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Out of hospital cardiac arrest in Saskatoon : an assessment of the emergency medical system Medd, Lorna May 1984

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OUT OF HOSPITAL CARDIAC ARREST IN SASKATOON: AN ASSESSMENT OF THE EMERGENCY MEDICAL SYSTEM BA (1966) B Sc. Med. By LORNA MAY MEDD (1970) MD (1970), U n i v e r s i t y of Manitoba A THESIS SUBMITTED IN PARTIAL FULFILMENT OF THE REQUIREMENTS FOR THE DEGREE MASTER OF SCIENCE i n THE FACULTY OF GRADUATE STUDIES (DEPARTMENT OF HEALTH CARE AND EPIDEMIOLOGY) We accept t h i s t h e s i s as conforming t o the r e q u i r e d s tandard THE UNIVERSITY OF BRITISH COLUMBIA October 1984 © Lorna May Medd, 1984 In presenting t h i s thesis i n p a r t i a l f u l f i l m e n t of the requirements for an advanced degree at the University of B r i t i s h Columbia, I agree that the Library s h a l l make i t f r e e l y available for reference and study. I further agree that permission for extensive copying of t h i s thesis for scholarly purposes may be granted by the head of my department or by h i s or her representatives. I t i s understood that copying or publication of t h i s thesis for f i n a n c i a l gain s h a l l not be allowed without my written permission. Department of I The University of B r i t i s h Columbia 1956 Main Mall Vancouver, Canada V6T 1Y3 Date Cur iv Abstract The question addressed i n t h i s thesis i s should the City of Saskatoon, Saskatchewan develop an emergency medical system (EMS) s p e c i f i c a l l y designed to deal with out-of-hospital cardiac arrest? In order to answer t h i s question, a series of subsidiary questions must be dealt with, as follows: 1. Can an EMS provide r e a l health gains i n terms of decreased morbidity and mortality from cardiac arrest? 2. What are the components of an EMS that are required to achieve t h i s decrease i n morbidity and mortality? 3. Is the community i n question t y p i c a l for cardiac arrest i n terms of sociodemographic, morbidity, and mortality patterns, or s u f f i c i e n t l y d i f f e r e n t from population data i n the published l i t e r a t u r e that the EMS w i l l be required to accommodate the differences? 4 . How important a cause of morbidity and mortality i s cardiac arrest, and w i l l i t become a greater or a lesser problem i n the next decade? 5. Is the establishment of such a service an e f f e c t i v e way of reducing morbidity and mortality from cardiac arrest, or are there ways of dealing with cardiac arrest that w i l l have more impact? The province of Saskatchewan and the City of Saskatoon are attempting to deal with these issues i n order to develop long range plans for an e f f e c t i v e and affordable ambulance service for both the province and the larger c i t i e s . The causes and extent of sudden cardiac death i n Canada and i n Saskatoon are described from reports i n the e x i s t i n g s c i e n t i f i c l i t e r a t u r e and l o c a l death r e g i s t r y data. The epidemiology of coronary heart disease (CHD) and the impact on mortality from CHD by an array of primary, secondary and t e r t i a r y preventive interventions are presented i n order to provide a context from which the most appropriate approach for Saskatoon may be chosen. Highly developed EMS1s i n North America are described from published reports. Their impact on mortality i s analysed, with p a r t i c u l a r attention paid to recent developments which appear most promising for Saskatoon and area. Features of the system which i s currently operating i n Saskatoon are drawn from data i n the annual reports of the Saskatoon and Area Ambulance Board from 1980 to 1983. Recommendations based on the compiled data are s p e c i f i c to Saskatoon and area and are related to the needs, e x i s t i n g services and structures, and available resources i n that community. i v TABLE OF CONTENTS Chapter Page No, I Statement of the Problem and Background 1 II Methodology 6 1. Sources of Data 2. Plan of Analysis III- The Epidemiology of Cardiac Arrest 11 1. Coronary Heart Disease 2. Sudden Cardiac Death IV- The System of Emergency Medical Services 36 1. Components of the System 2. Recent Modifications 3. Impact of the System V Emergency Medical Services i n Saskatoon 56 1. The Pr o v i n c i a l Context 2. The System i n Saskatoon 3. Epidemiology of Cardiac Arrest i n Saskatoon 4. A Proposal with Alternatives VI Summary and Recommendations 77 Bibliography Appendix A Appendix B 81 85 86 V LIST OF FIGURES Figure 1 Age-Adjusted Death Rates 12 for Ischemic Heart Disease, By Color and Sex. United States 1950-76 Figure 2 Age-Adjusted Death Rates 15 from CHD Among Men Aged 35-74. Figure 3 a-d Factors Causing the Coronary 17 Mortality Decline and the Measure of t h e i r Contribution Figure 4 The Role of Preventive Strategies i n CHD 29 v i LIST OF TABLES Countries with a Decrease or Increase i n Rate of Mortality Due to Coronary Heart Disease (men aged 35 to 74 years, 1969 to 1977) Rates of Survival (%) for Paramedic-Treated or EMT-Treated Cases of Cardiac Arrest Rates of Survival (%) Following Bystander-I n i t i a t e d CPR Age-Standardized Mortality Rates for CHD 1 9 7 3 - 1 9 7 9 i n Selected Canadian C i t i e s Deaths from Acute Myocardial Infarc t i o n (ICDA Code 410) Saskatoon 1 9 8 0 - 1 9 8 3 v i t Acknowledgements I am very pleased to be able to express my thanks to the members of my thesis committee for t h e i r encouragement and advice. Dr. Cort Mackenzie has provided invaluable assistance at a l l stages of my program and his guidance has been c r u c i a l to the completion of the study. I am indebted to Dr. Anne Crichton for her perceptive analyses of the approach and her c r i t i c a l i n s i g h t s into the arguments herein. Dr. Morton Warner has been a constant source of support, and his ideas have influenced me greatly. My association with these advisors has r a d i c a l l y changed my understanding of health and health care, and I owe them a great debt of gratitude. Any errors, and the l i m i t a t i o n s of t h i s study are s o l e l y my r e s p o n s i b i l i t y . October 1984 Lorna Medd 1 Chapter I Statement of the Problem and Background The question dealt with i n t h i s thesis i s should the Ci t y of Saskatoon, Saskatchewan develop an emergency medical service system (EMS) designed s p e c i f i c a l l y to deal with out-of - h o s p i t a l cardiac arrest? The question cannot be answered u n t i l a series of subsidiary but necessary questions are f i r s t addressed. 1. Can an EMS be expected to provide r e a l health gains i n terms of decreased morbidity and mortality from cardiac arrest? 2. What are the components of an EMS that are required to achieve t h i s decrease i n morbidity and mortality? 3. Can a c i t y with a population of 170,000 support a service that f u l f i l l s these requirements? 4. How important a cause of morbidity and mortality i s cardiac arrest, and w i l l i t become a greater or a lesser problem i n the next decade? 5. Is the establishment of such a service an e f f e c t i v e way of reducing morbidity and mortality from cardiac a r r e s t , or are there ways of dealing with cardiac arrest that w i l l have more impact? 2 E f f o r t s to resuscitate the dead are as old as hi s t o r y i t s e l f , and the r e s u s c i t a t i o n techniques of many cultures and eras have been documented. Sudden cardiac death has been depicted i n Egyptian r e l i e f sculpture from the tomb of a noble of the Sixth Dynasty, approximately 4500 years ago."*" Mouth to mouth re s u s c i t a t i o n i s described i n the Bible (II Kings 4 2 (34) King James Version) and there have been h i s t o r i c a l attempts to revive an i n d i v i d u a l e l e c t r i c a l l y . The i n s t i t u t i o n a l i z a t i o n of r e s u s c i t a t i o n i n contemporary terms began i n the I960's with the advent of coronary care 3 units (CCU). In 1967 Pantridge and Geddes published a landmark paper describing mobile coronary care units ("flying squads") operating i n the streets of B e l f a s t . A rapid and widespread evolution of si m i l a r emergency medical response systems followed immediately. These systems were directed toward preventing deaths from coronary heart disease (CHD) which at that time had reached the peak of i t s epidemic curve. The modern o r i g i n s of out-of-hospital emergency medical services (EMS) are thus i n e x t r i c a b l y linked to sudden death from cardiac disease. EMS has come to be defined as programs that d e l i v e r d e f i n i t i v e care for cardiopulmonary arrest (CPA) i n the f i e l d . Although there are other applications for EMS, cardiac patients remain the single largest user group. Non-cardiac arrest uses of emergency medical services w i l l not be addressed i n the paper. 3 A f u l l y developed EMS system i s large, technologically complex and c o s t l y . Its components include a mechanism for rapid access to the system, usually a universal emergency number such as 911; c i t i z e n s trained to d e l i v e r CPR; f i r s t response units staffed with personnel trained and e f f e c t i v e i n d e l i v e r i n g basic l i f e support (BLS); paramedic units with more highly trained s t a f f able to d e l i v e r the wider range of services (many of them physician-delegated) that comprise advanced cardiac l i f e support (ACLS). Examples of ACLS techniques include d e f i b r i l l a t i o n , establishment of intravenous l i n e s , EKG interpretation and drug administration. Because time i s so c r u c i a l a factor i n a successful response and because of the technologically sophisticated support systems required, EMS works best i n large metrop-o l i t a n areas. Rural communities have rarely been considered appropriate s i t e s for paramedic units, although the inequity of e s t a b l i s h i n g an EMS for a c i t y but not for nearby smaller communities i s an important issue. When s p e c i f i c questions about developing an EMS are posed, there are two major obstacles that prevent the development of complete answers. The f i r s t i s the s c a r c i t y of r e l i a b l e supporting data. Research into and evaluation of emergency medical services as one component of the health care system has i n t e n s i f i e d , but u n t i l recently the q u a l i t y and quantity of the data have not been adequate to provide a basis for making informed judgments on the u t i l i t y of the 4 system. The second obstacle i s the sheer force of the emotional component involved i n the provision of emergency ambulance services. Policy planners may be able to deal i n the abstract with numbers and q u a l i t y of l i v e s saved by competing systems, but one t e l e v i s i o n c l i p of an ambulance at the scene of a collapse, l i g h t s f l ashing, with paramedics r e s u s c i t a t i n g an i n d i v i d u a l on the pavement can overpower reasoned judgment i n the minds of taxpayers. The most r a t i o n a l arguments i n favor of preventing such a scenario instead of dealing with i t a f t e r - t h e - f a c t go by the board. This study arose from the e f f o r t s of the Saskatoon and Area Ambulance D i s t r i c t Board (SAADB) to plan and d i r e c t the evaluation of ambulance services i n the C i t y of Saskatoon and surrounding r u r a l d i s t r i c t s . The Board i s developing a plan i n concert with e f f o r t s by the p r o v i n c i a l planning unit, the Ambulance Services Unit, to e s t a b l i s h a uniformly adequate EMS across the province of Saskatchewan. In the near future the Board w i l l be dealing with issues of equity of access for r u r a l and urban constituents, the costs and benefits of e s t a b l i s h i n g a 911 system, the optimum l e v e l of t r a i n i n g for ambulance personnel, sources of funding for s a l a r i e s i f personnel are required to take add i t i o n a l t r a i n i n g , and optimal deployment of ambulance units within the D i s t r i c t . This paper attempts to provide information that may a s s i s t the Board in i t s deliberations. 5 Chapter I Notes 1. Lown, B. "Sudden Cardiac Death: The Major Challenge Facing Contemporary Cardiology." Amer. J. C a r d i o l . 4_3 February 1979. pp. 313-28. p. 313. 2. Warren, J.V. "Delivery System for Emergency Cardiac Care: The Medical Plan of Action." Amer. J. C a r d i o l . 50. August 1982. pp. 370-72. p. 370. 3. Pantridge, J.F., J.S. Geddes. "A Mobile Intensive Care Unit i n the Management of Myocardial I n f a r c t i o n . " Lancet 2. 1967. pp. 271-73. 6 Chapter II Methodology 1. Sources of Data The epidemiologic features of the group who most need emergency ambulance services are described i n Chapter I I I , The Epidemiology of Cardiac Arrest. This chapter also situates ambulance services within the context of the c l a s s i c a l model of l e v e l s of prevention (primary, secondary, t e r t i a r y ) as applied to diseases causing cardiac arrest. I t discusses evidence for the primary and secondary prevention of those diseases, including maximum numbers of people i n cardiac arrest affected by emergency medical services under i d e a l s i t u a t i o n s . Data for t h i s discussion are drawn from the published l i t e r a t u r e . Chapter IV describes the development of emergency medical services i n general terms from the mid-1960's to the present. The history of the service, the f u l l y developed model as i t e x i s t s i n a few urban centres i n the United States, and the impact i n terms of length of s u r v i v a l are taken from analyses published i n the current l i t e r a t u r e . The comparative analysis of three Canadian c i t y systems i s derived from consultants' studies c a r r i e d out on behalf of those c i t i e s and from discussions with in d i v i d u a l s who have observed those systems fi r s t h a n d . 7 Chapter V, Emergency Medical Services i n Saskatoon, has been developed from documentary data available from p r o v i n c i a l and municipal sources. Sociodemographic data has been taken from Neighborhood Profiles"*", a document published by the Ci t y of Saskatoon Planning Department using 1981 Census data and 1983 p r o v i n c i a l population figures. The epidemiology of cardiac arrest i n Saskatoon i s derived from l o c a l v i t a l s t a t i s t i c s information available from the Saskatoon Community Health Unit and the University of Saskatchewan Department of Social and Preventive Medicine. The analysis of the operation of the SAADB ambulance system was developed from the Annual Reports 1980-83 of the ambulance d i s t r i c t operation. The primary data that form the basis for the reports consist of the i n d i v i d u a l ambulance run reports, formatted for and analyzed by a computer program developed by Joan Feather of the University of Saskatchewan Department of Social and Preventive Medicine. The program i s run by the Hospital Systems Study Group (HSSG) and data processing was car r i e d out by HSSG personnel. 2. Plan of Analysis The analysis of the data has been structured by 2 Chambers' need/demand-supply model. In t h i s model, need i s defined as: 8 "...services that should be provided to the public on the basis of the perceptions of the experts... This includes i n t e r p r e t a t i o n of need for health services on the basis of health status information about target groups." Need thus includes epidemiological analyses and assessment by "experts" in the f i e l d . Demand i s defined as: "...the types and amounts of health services requested or desired by the public once they know the costs and prices involved... Con-sumers' wants change with additional knowledge of what i t w i l l cost (or what altern a t i v e s would be foregone) to f u l f i l l them... frequently demand i s expressed i n public action by informed consumers." Supply i s defined as: "...a consideration of 'the numbers and d i s t r i b u t i o n s of f a c i l i t i e s and health personnel r e l a t i v e to the populations they serve,' or a consideration 'of the q u a l i t y of care provided by these services," The Epidemiology of Cardiac Arrest coupled with the Saskatoon data on cardiac arrest, i s intended to provide an estimate of need. The description of the components of the system i n both general and s p e c i f i c terms represents supply. Demand, or want informed by knowledge of cost, i s not easy to t y p i f y . In large part t h i s i s because the r e l a t i v e costs and benefits of alternatives or options to be foregone are not well understood, and have yet to be elucidated by further research. To complicate the paucity of data, competing i n t e r e s t groups ( i . e . c a r d i o l o g i s t s and community physicians) may present c o n f l i c t i n g and opposite pictures of demand 9 using the fragments of information that are a v a i l a b l e . A t h i r d complicating issue i s the fact that i n a discussion of t h i s most concrete " l i f e - o r - d e a t h " issue, r a t i o n a l i t y becomes clouded by emotion more than i t would i n more abstract "health" debates. The f i n a l recommendations of the study have evolved from a comparison of need/demand and supply, and seek to i d e n t i f y gaps or overlaps i n service. They also address the a l t e r n a t i v e options for saving l i v e s , which w i l l be foregone i f resources are allocated to an EMS. 10 Chapter II Notes 1. Neighborhood P r o f i l e s . C i t y of Saskatoon Planning Department. May 1984. p. 54. 2. Chambers, L.W., C. Woodward, C. Dok. Guide to Health Needs Assessment: A Crit i q u e of Available Sources of Health and Health Care Information. McMaster University Faculty of Health Sciences (mimeograph). November 1979. p. 3. 11 Chapter III The Epidemiology of Cardiac Arrest Coronary heart disease (CHD) i s the leading cause of death i n the i n d u s t r i a l i z e d world. In Canada i n 1977 49% of a l l deaths were due to diseases of the c i r c u l a t o r y system. These diseases were also the leading cause of h o s p i t a l i z a t i o n and p o t e n t i a l years of l i f e l o s t and were the most s i g n i f i c a n t cause of d i s a b i l i t y . Diseases of the c i r c u l a t o r y system have been i d e n t i f i e d as the top public health problem in Canada.^ In the United States i n 1978, 985,800 persons died of heart or blood vessel disease (51% of a l l deaths). Up to 1.5 m i l l i o n people were expected to have heart attacks i n 1981 with a r e s u l t i n g 650,000 deaths. 4.3 m i l l i o n l i v i n g Americans have a hi s t o r y of acute myocardial i n f a r c t i o n (AMI), angina or both. For 1981 the projected cost of a l l cardiovascular disease i n the United States was $46.2 b i l l i o n , not counting losses i n management s k i l l s , production experience, personnel 2 development and labour. In spite of the pervasiveness of t h i s epidemic of heart disease, there has been a remarkable decline i n deaths from CHD i n recent years. The decline began between 1964-69 but i t was not f u l l y appreciated or accepted as r e a l u n t i l around 1978. Figure 1 shows trends i n age-adjusted death rates due to cardiovascular disease i n the United States between 1950-1976. The breaks i n the curves represent the 12 Avwtton* o) ttw tnt*rtwt«n«i Cta»t>c»tton 0 f p n u n 1 WMta rnalt All otter m t o . v # • V 1 / / •s / * 4 All ottar *»mala >s . ... s \ N \ \ \ \ s v Whtta tamat. T E A K Figure 1. Age-adjuated death r a t a * f o r lachemlc heart dlaeaaa, by c o l o r and sex: United S t a t e s , 1950-76 Figure 1 reprinted by permission from the National Heart, Lung and Blood I n s t i t u t e Working Group on Heart Disease Epidemiology NIH publication #79-1667 June 1979 3 major revisions i n c l a s s i f i c a t i o n codes of ICDA. The decline has affected a l l age groups, both sexes, and three e t h n i c / r a c i a l groups. Between 1968 and 1976 the age-adjusted o v e r a l l mortality from ischemic heart disease i n the United States declined by 3 20.7%, and by 24% for persons over 85 years of age. If the 1968 death rates had prevailed i n 1978, about 114,000 more deaths would have occurred. For the entire decade there 13 were 568,000 deaths expected that did not occur. In Canada between 1969 and 1977, mortality-rates for CHD dropped 14% for males and 21% for females 5 - o v e r a l l 16.4%.6 However, h o s p i t a l i z a t i o n rates for the same diseases increased. These findings may be consistent with some improvement i n the case f a t a l i t y rate of ind i v i d u a l s h o s p i t a l i z e d with myocardial 7 i n f a r c t i o n . There are some s t r i k i n g differences i n the pattern of de c l i n i n g rates across the i n d u s t r i a l i z e d nations. Table I shows the ranking of ten i n d u s t r i a l i z e d nations experiencing a decline between 1969 and 1977, and 17 i n d u s t r i a l i z e d nations showing an increase over the same time period. Among nations with d e c l i n i n g rates, Canada ranks t h i r d , with a decline somewhat less than the remarkable changes demonstrated i n the United States and A u s t r a l i a . 14 TABLE I Countries With Decrease or Increase in Rate of Mortality Due to Coronary Heart Disease (men aged 35 to 74 years, 1S69 to 1977) 1969 .1977 % Country Rate Rate Difference Difference A. Countries With a Decrease in Rate United Slates 864.7 669.5 - 1 9 5 .2 - 2 2 . 6 Australia 843.7 683 .1 - 1 6 0 . 6 - 1 9 . 0 Canada 703.3 624.1 - 7 9 . 2 - 1 1 . 3 Israel 653.3 581.0* - 7 2 . 3 - 1 1 . 1 Norway 582.9 537.1 - 4 5 . 8 - 7 . 9 Japan 126.3 102.6 - 2 3 . 7 - 1 8 . 8 Belgium 446.1 426.8* - 1 9 . 3 - 4 . 3 Finland 893.7 876.0* - 1 5 . 7 - 1 . 8 Scotland 813.7 808.6 - 5 . 1 - C . 6 Italy 313.0 309.6" - 3 . 4 - 1 . 1 B. Countries With an Increase in Rale Bulgaria 299.3 423.5 + 124.2 + 41.5 Poland 186.5 307.7 + 121.2 + 65.0 North Ireland 782.4 867.1 + 84.7 + 10.8 Rumania 170.5 237.3 + 66.6 + 39.2 Hungary 441.6 499.2 + 57.6 + 13.0 Yugoslavia 185.0 227.6 + 42 .6 + 23.0 Sweden 523.9 560.1 + 36.2 + 6.9 Ireland 662.2 697.7" + 35.5 + 5.4 German Federal 427.3 456.1 + 3C.8 + 7.2 Republic Austria 428.3 455.3 + 27.0 + 6.3 New Zealand 773.3 747.1 + 26.2 + 3.4 Switzerland 290.4 312.7 + 22.3 + 7.7 Netherlands 476.7 500.5 + 21.8 + 4.6 France 195.2 206.9* + 11.7 + 6.0 Denmark 566.1 576.3 + 10.2 + 1.8 Enoland and Wales 662.1 •671.7 +9.6 + 1.4 Czechoslovak ia 587.9 590.4' + 2.5 + 0.4 * 1976 data. " 1975 data. ICD 410 -14 , 8th revision. Rates per 100.000 population are averages of the rates for men aged 35 to 44. 45 to 54. 55 to 64. 65 to 74. Reprinted by permission from Stamler Jeremiah, Amer. J. Cardiol 47 March 1981.4 15 Figure 2 presents these changes i n rates for a more select group of nations. In Japan throughout t h i s time period, rates have been consistently low. A u s t r a l i a and the United States began the period with high rates but by the end of the decade the rates were comparable to those i n England and Wales, where a small increase had taken place. Developing his argument from the data i n the graph, Rose stated that the B r i t i s h are f a i l i n g g to prevent a preventable disease. The question i s , what i s happening i n the United States, A u s t r a l i a and Canada that i s not happening i n the United Kingdom? 800 700 600 o %. K 5 0 0 g 400 * 300 o D 200 H 100 USA Australia 8.T • -'8 England and Wales , . P " . o - - 0 " - o . . . . o - - 0 - - o o—• o-" Sweden Japan 1968 70 72 - 74 76 77 Figure 2. Age-adjusted death rates from CHD among men aged 35-74. Reprinted by permission from Rose, G, B r i t i s h Medical Journal 282 1981.^8 16 In the nations with s i g n i f i c a n t decreases i n mortality, the decline has been large enough and consistent enough that p o t e n t i a l a r t e f a c t s such as changes i n completing and coding death c e r t i f i c a t e s are considered inconsequential and the decline from peak rates has been judged as r e a l . However, a f u l l y s a t i s f a c t o r y explanation for the decline has not yet been found. Is the reduction a consequence of reduced incidence (fewer people get heart disease, but the same proportion die from i t ) or increased s u r v i v a l (the same number get heart disease but fewer die, either because the disease i s milder or because of improved intervention)? Figures 3a-3d show some of the possible contributions of the various primary 9 and secondary interventions to the decline i n coronary mortality. Not unexpectedly, there are strong proponents for nearly every possible contributing intervention. ^ Stern has reviewed the possible causes of the decline and the evidence for each.'*"''" There i s l i t t l e information on what i s happening to incidence, but Stern postulated that i f incidence rates were i n fact known to be dropping, the decline i n mortality could be a t t r i b u t e d to primary prevention. If the incidence rate i s steady (or r i s i n g ) the decline i n mortality could be a t t r i b u t e d to secondary prevention (improved medical care of patients with c l i n i c a l l y manifest coronary disease). Stern d i d not examine the p o s s i b i l i t y that the disease i s becoming less l e t h a l . However, i t i s u n l i k e l y that the nature of the disease could change so much i n a ten Figure 3, a-d. Reproduced From: C A N WE IDENTIFY FACTORS C A U S I N G THE C O R O N A R Y MORTALITY DECLINE A N D M E A S U R E THEIR CONTRIBUTION? The Epidemiology of Cardiovascular disease; Lecture notes (mimeo) Herman Tyroler Minneapolis 1931 "^"z 1. Z "" — tMS/cpn 18 year period. There are recent data from Minnesota that i n d i c a t e a 9% drop i n incidence of AMI between 1965 and 1975, 13 and a p a r a l l e l 48% decline i n f a t a l i t y rate. Primary prevention of CHD involves preventing or e l i m i n a t i n g known r i s k factors for the disease. The "big three" r i s k factors for CHD are hypertension, elevated serum ch o l e s t e r o l l e v e l s from a d i e t high i n cholesterol and saturated f a t , and cigarette smoking. Lesser r i s k factors include type A personality, physical i n a c t i v i t y , obesity and . . . 14 perhaps abnormalities of coagulation , including fibrinogen i , 15 l e v e l s . One argument i n favor of r i s k factor reduction as a major contributor to d e c l i n i n g mortality rates examines the chronological order of events. In 1960 the American Heart Association issued i t s f i r s t statement on cigarette smoking and cardiovascular disease. This was followed i n 1961 by i t s f i r s t statement on d i e t and coronary heart disease. In 1964, the year of the f i r s t decline i n CHD mortality, the Surgeon General published his landmark statement on the hazards of c i g a r e t t e smoking. In 1973 the National High Blood Pressure Education Program was launched to tackle hypertension, which was i d e n t i f i e d as an American national public health priority."*"^ P a r a l l e l changes i n consumption of s p e c i f i c related products occurred from 1963 to 1980. The percent change i n consumption of cigarette tobacco was -27.1%, f l u i d milk and cream -24.1%, butter -33.3%, eggs -12.3%, animal fats and 19 o i l s -38.8%, vegetable fats and o i l s +57.6% and f i s h +22.6%. Furthermore, the penetration of hypertension detection and control programs has been far greater than expected and i s 18 thought to have had a major role i n the decline. However, the l i n k between the decline i n r i s k factors and the decline i n mortality i s not a straight l i n e r e l a t i o n -ship. Where a l l socioeconomic strata have experienced the decline i n mortality i t has been demonstrated that cessation of smoking and increased physical exercise have been 19 d i f f e r e n t i a l l y taken up by the higher socioeconomic groups. In Canada the prevalence of cigarette smoking declined by 16% between 1965-77, but women and younger age groups have changed t h e i r tobacco consumption minimally and yet are experiencing proportionately greater declines i n t h e i r mortality from CHD than older males.^ About 46% of the Canadian population now regularly p a r t i c i p a t e s i n some form of physical exercise; however, the longterm impact has not yet been assessed because the 21 phenomenon i s so recent. Stern concluded the review of the role of r i s k factor reduction i n the decline i n mortality by a t t r i b u t i n g half the decline i n white males and one-third 22 the decline i n white females to primary prevention. Secondary preventive measures include coronary care units, out-of-hospital emergency medical services (EMS) and coronary bypass surgery. A l l have been credited with some impact on the decline i n mortality rates. 20 There have been two study designs employed to prove that coronary care units (CCU) lower mortality: those using h i s t o r i c a l controls, and randomized controlled t r i a l s . Pre-CCU era f a t a l i t y rates of 30-40% may be contrasted with the current 10-20% achieved i n CCU's. However, the use of h i s t o r i c a l controls ignores the p o s s i b i l i t y of changes over time i n the c h a r a c t e r i s t i c s of patients hos p i t a l i z e d with acute myocardial i n f a r c t i o n . there i s wide v a r i a t i o n i n the mix of mild and severe cases i n pre- and post-CCU studies, and pre-CCU mortality rates as low as 15% have been reported, as have post-CCU rates as high as 48%. It i s also possible that the case f a t a l i t y rates are better i n the post-CCU era because physicians are h o s p i t a l i z i n g milder cases with better prognoses. Previously 20-40% of a l l myocardial i n f a r c t i o n s were unrecognized or " s i l e n t " , but with increasing p u b l i c i t y , patients' awareness and physicians' index of suspicion may be heightened, with the r e s u l t that milder cases may now be being h o s p i t a l i z e d . The prospective randomized controlled t r i a l s c arried out to 2 3 24 date have both been i n England. ' While neither showed an advantage for coronary care units, both studies have been c r i t i c i z e d for not dealing with the c r i t i c a l two hours aft e r onset of symptoms by not beginning randomization u n t i l r e l a t i v e l y l a t e i n the prehospital phase. Presumably both studies thereby select for a group that survived the highest r i s k period, making i t d i f f i c u l t to show an advantage of 21 CCU's over care at home. A retrospective randomized survey of urban and r u r a l Manitoba ho s p i t a l records i n 1974-1976 revealed mortality rates from acute myocardial i n f a r c t i o n (AMI) of 14-15%. There was no s i g n i f i c a n t difference i n mortality rates from AMI for urban hospitals with CCU's or r u r a l hospitals equipped at best with a monitor and d e f i b r i l l a t o r . There was only a suggestion of a better outcome for urban hospitals. The authors postulated that the dissemination to the r u r a l h o s p i t a l s ' of the p r i n c i p l e s of sophisticated coronary care i f not the technologic c a p a b i l i t y / was the factor responsible for 2 6 comparable CCU and non-CCU rates. Improvements i n hospital coronary care beyond a 10-2 0% mortality rate w i l l have minimal impact on o v e r a l l CHD mortality. The major c r i t i c i s m of the impact of CCU's on CHD mortality i s that two-thirds of the patients have been dying before ever reaching a CCU. If a greater percentage of victims of acute myocardial i n f a r c t i o n have been reaching hospital because of improved EMS, the f a l l i n case f a t a l i t y rates would be expected to have had a correspondingly greater impact on o v e r a l l mortality. This area requires further study. The impact of emergency medical services (programs that d e l i v e r d e f i n i t i v e care for cardiorespiratory arrest i n the f i e l d ) i s easier to analyze than the impact of CCU's. Prototype systems such as those i n Seattle and Miami report that from 10-25% of patients with documented out-of-hospital 22 v e n t r i c u l a r f i b r i l l a t i o n are eventually discharged from 27 28 h o s p i t a l and about 7-10% survive longterm. ' Eisenberg has stated that a well developed program can lower the annual mortality from ischemic heart disease on a 29 community-wide basis by 8.4%. However, as Stern pointed out, such programs are rare and could not possibly have affected o v e r a l l national mortality. Only 68 of the 304 American Emergency Medical Services Regions are i n the advanced l i f e support phase of a fe d e r a l l y sponsored program designed to 30 achieve t o t a l national coverage by 1982. Since Stern's review of the role of primary and secondary prevention, r e s u l t s have come in from a number of major multiple r i s k factor intervention t r i a l s conducted throughout the i n d u s t r i a l i z e d world. It had been anticipated that the effectiveness of primary prevention could be established by demonstrating that reducing r i s k factors would reduce the incidence of and mortality from CHD. There was surprise and dismay when the r e s u l t s turned out to be equivocal. Unlike e a r l i e r t r i a l s which modified r i s k factors p o s t - i n f a r c t , these c l i n i c a l t r i a l s selected subjects who were free of c l i n i c a l heart disease at entry into the study. The best known of these t r i a l s include MRFIT (U.S.), the North Karelia study (Finland), the Oslo t r i a l (Norway) and the WHO European Coronary Prevention Study. Most of the t r i a l s were not blinded e i t h e r because i t was impossible, as with smoking cessation, or unethical, as 23 for example a no-treatment group for hypertension. It was also recognized that multiple interventions would be s c i e n t i f i c a l l y less precise than single factor intervention. The MRFIT was a randomized primary prevention t r i a l involving 12,866 high-risk males aged 35-57 years who were randomly assigned either to a special intervention program consisting of stepped-care treatment for hypertension, counselling for smokers, dietary advice to reduce choles t e r o l l e v e l s , or to the usual sources of health care i n the community. The average followup period was seven years. In both groups there was a greater than expected reduction i n a l l three r i s k factors. However, the mortality rates i n the s p e c i a l intervention group were not s i g n i f i c a n t l y d i f f e r e n t from those i n the 31 usual care group, although they were 7% lower. Three explanations for these findings were considered: 1) The o v e r a l l intervention program did not a f f e c t CHD mortality. This was rejected as inconsistent with most published s c i e n t i f i c data. 2) The intervention does a f f e c t CHD mortality but the benefit was not observed i n t h i s t r i a l of 7 years' duration. If t h i s i s true then i t i s d i f f i c u l t to continue to a t t r i b u t e 30-50% of the decline i n mortality between 1969 and 1978 to changes i n r i s k factors i n the population at large. I t was concluded on the basis of recalculations that 24 the second explanation was u n l i k e l y . 3) Measures to decrease c i g a r e t t e smoking and lower c h o l e s t e r o l may have decreased m o r t a l i t y w i t h i n subgroups of the s p e c i a l i n t e r v e n t i o n cohort, whereas there may have been an unfavorable change i n m o r t a l i t y r a t e s among hypertensive 32 men w i t h abnormal EKG's on treatment f o r hypertension. The combination of favorable and unfavorable e f f e c t s c a n c e l l i n g out what might have been a s i g n i f i c a n t lowering of m o r t a l i t y r a t e s i s p r e s e n t l y the i n t e r p r e t a t i o n accepted f o r the MRFIT r e s u l t s . However, O l i v e r (Edinburgh) has reviewed the r e s u l t s of MRFIT, the North K a r e l i a community i n t e r v e n t i o n and the WHO European Coronary Prevention Study and has come to the c o n c l u s i o n t h a t "the evidence against any s u b s t a n t i a l b e n e f i t to the community from m u l t i p l e r i s k f a c t o r i n t e r v e n t i o n i s 33 i n c r e a s i n g . " Although i n North K a r e l i a there was an aggregated f a l l of 17% i n coronary r i s k f a c t o r s , when compared to the c o n t r o l province Kuopio there was no change i n the i n c i d e n c e of coronary heart disease. In the WHO study there was no change i n incidence of CHD and i n the B e l g i a n s e c t i o n a s m a l l increase occurred. "The F i n n i s h , American (MRFIT) and WHO f i n d i n g s — i n s t r i c t primary prevention t e r m s - - a l l suggest t h a t m u l t i p l e r i s k f a c t o r i n t e r v e n t i o n does not work i n 34 middle-aged men." O l i v e r recommended adoption of a more s e l e c t i v e p o l i c y of i n t e r v e n t i o n f o c u s i n g on those at highest r i s k even though they are a r e l a t i v e l y smaller group. 25 By contrast, Walker (United States) interpreted the MRFIT re s u l t s to conclude the exact opposite, that r i s k factor reduction i s indicated for a l l , not just those i d e n t i f i e d as 35 high r i s k . He pointed out that the usual care subjects made s i g n i f i c a n t changes to t h e i r r i s k factors, and that t h e i r observed mortality rates were 41% lower than expected. Further, the mortality rate from CHD was 21% lower i n normotensive males i n the dietary intervention group than among the controls. However, t h i s e f f e c t was countered by a higher mortality i n a treated subgroup of hypertensives. Walker also reviewed findings from the Oslo Study Group (1981) which had c a r r i e d out a prospective randomized f i v e year study of d i e t and smoking with intervention i n normotensive males at high r i s k for CHD. In the intervention group the incidence of myocardial i n f a r c t i o n and sudden death was reduced by 4 7%. Interpretation of these r e s u l t s has been r e l a t i v e l y straightforward i n contrast to the MRFIT r e s u l t s . The impact of primary preventive measures on the incidence of and mortality from CHD i s not yet c l e a r . However, as Stern recommended, "... lack of d e f i n i t i v e data on the causes of the decline should not be used as an excuse to slow the 3 6 implementation of plausible public health measures." 26 The Syndrome of Sudden Cardiac Death "Sudden cardiac death i s the leading cause of f a t a l i t y in the i n d u s t r i a l l y developed world. In the United States, someone dies unexpectedly every 75 seconds, day or night. Sudden cardiac death has been shadowing man's l i f e since the inception of recorded history. The unpredict-a b i l i t y of i t s occurrence burdens our dreams and provides an awesome reminder of the f r a g i l i t y of our biology. While i t i s recognized that sudden cardiac death i s due to an e l e c t r i c a l derangement of heart rhythm known as v e n t r i c u l a r f i b r i l l a t i o n , no c l e a r acute morphologic lesions i n the heart have been i d e n t i f i e d which tr i g g e r t h i s event." "Sudden cardiac death presents a paradox: a massive, unheralded catastrophe, yet i n the heart a paucity of changes. Extensive coronary artery disease i s the r u l e , but the severity and d i s t r i b u t i o n are not d i s t i n c t i v e . The underlying process i s known to be caused by atherosclerosis but the trigger for the terminal, nearly instantaneous event remains undefined."37 Lown's dramatic statement above conveys the gravity and mysteriousness that makes the issue of r e s u s c i t a t i o n for sudden cardiac death (SCD) such an emotionally charged issue. Over two-thirds of SCD occur out-of-hospital, usually within two hours of the onset of symptoms. For 25% of victims, 3 8 SCD i s the f i r s t sign of heart disease. Kuller et a l described the prodromal symptoms and other features of SCD and found that a large number of t h e i r group of patients had already had evidence of cardiovascular disease at the time of death. 38% had received medical care within the previous two weeks, so the collapse i s not e n t i r e l y unheralded. Surveys from the Seattle Medic I system have characterized 27 the range of conditions which caused out-of-hospital cardiac arrest and prompted a c a l l to the emergency medical service. Sudden cardiac deaths (as distinguished from cardiac arrest secondary to non-cardiac disease) comprise the great majority of these deaths. Traumatic causes of cardiac arrest were excluded from these ser i e s . Sudden Cardiac Death in King County, Washington CAUSE OF DEATH LOCATION, YEAR CITY 1978 3 9 SUBURBS 1979' No. % No. % primary heart disease 931 79.0 528 81.4 respiratory disease 39 3.3 17 2.6 cancer 38 3.2 26 4.0 neurologic disease 37 3.1 18 2.8 sudden infant death syndrome 23 2.0 10 1.5 drowning 20 1.6 14 2.2 valvar heart disease 14 1.2 — alcoholism 13 1.1 10 1 . 5 overdose/suicide 12 1.0 7 1.1 overdose/non-suicide 12 1.0 6 0.9 a l l other 40 3.5 13 2.0 1179 100 649 100 40 28 In suburban King County the average age of a l l cardiac arrest patients was 61 years and of heart disease patients, 65 years. Men comprised 72% of the t o t a l group and 74% 4 0 of the primary cardiac group. Another study from suburban King County described 41 the epidemiology of cardiac arrest i n children. Over a si x year period (1976-1982) 119 cardiac arrests receiving emergency r e s u s c i t a t i o n were documented, for a rate of 12.7/100,000 individ u a l s l e s s than 18 years of age. Sudden infant death syndrome accounted for 38 cases (32%). The next two commonest causes were drowning, 22%, and respiratory causes, 9%. Nearly half the arrests occurred i n chi l d r e n under one year of age. Asystole was the most common presenting rhythm (77%) with v e n t r i c u l a r f i b r i l l a t i o n being the presenting rhythm i n only 9%. Overall, 8 (7%) of the c h i l d r e n were successfully resuscitated and discharged a l i v e from h o s p i t a l . Over half of these were near drownings. There were no resuscitations from among the sudden infant death group. During a comparable time period i n the same service area 20% of adults were successfully resuscitated and discharged a l i v e . The major d i s t i n c t i o n between adult and p e d i a t r i c age groups i n cardiac arrest i s the etiology. The high incidence of sudden infant death and drowning i n children contrasts sharply with the etiology i n adults, where coronary heart disease causes 80% of cardiac arrests. 29 Figure 4 i s an e f f o r t to summarize the role of prevention i n CHD. Figure 4 The Role of Preventive Strategies i n CHD •Health No t B i o l o g i c a l t . No r i s k Atherosclerosis factors Socioeconomic PRIMARY PREVENTION per i o d i c exam for high r i s k groups screening for hypertension behavior modification multiple r i s k factor intervention t r i a l s •No C l i n i c a l Heart Angina ^ Disease AMI I CHD SCD J SECONDARY PREVENTION -EMS -ecu -Drug Therapy, Surgery • C l i n i c a l Disease •Sudden Cardiac Death TERTIARY PREVENTION Antiarrhythmics Rehabilitation •Implantable Cardioverter • Recurrent SCD • Anoxic Damage 30 From the diagram i t may be seen that the outcome of primary prevention i n the s t r i c t e s t sense i s absence of CHD, although i n the l i t e r a t u r e reviewed i t i s generally taken to mean absence of c l i n i c a l heart disease including sudden cardiac death. At t h i s early stage, prevention includes f a m i l i a l and socioeconomic variables which are d i f f i c u l t to modify, and absence of the c l a s s i c a l r i s k factors of smoking, hypertension, elevated cholesterol l e v e l , obesity, lack of physical exercise, and Type A personality behavior. Primary prevention includes measures designed to intervene and treat before expression of disease. It was e a r l i e r noted that i n 20-25% of cases the f i r s t manifestation of disease i s sudden cardiac death. Preventive measures i n t h i s category include the f u l l range of techniques available to modify smoking and dietary behavior, periodic examination of high r i s k groups, screening and tr e a t i n g hypertension, and the multiple r i s k factor intervention t r i a l s . Secondary prevention includes measures designed to reduce the severity and sequelae of established disease; i n t h i s case myocardial i n f a r c t i o n and sudden cardiac death. Out-of-hospital emergency medical services, coronary care units and other d e f i n i t i v e treatment and r e h a b i l i t a t i o n programs are the major secondary l e v e l interventions. Kuller has stated that of the 400,000 people i n the U.S. dying each year of SCD about 20,000-40,000 could be saved by CCU's and e f f e c t i v e EMS, and that i t was clear that primary 31 prevention was the only f e a s i b l e longterm route. T e r t i a r y prevention minimizes the impact and sequelae of established disease and there are two issues i n p a r t i c u l a r to be considered i n t h i s realm. Resuscitation introduces a whole new complex of p o s s i b i l i t i e s , including the syndrome of "recurrent sudden death" and the tragedy of in d i v i d u a l s who have been "successfully"revived but have sustained s i g n i f i c a n t anoxic damage and major motor or i n t e l l e c t u a l d e f i c i t s . 32 Chapter III Notes 1. Morgan, P.P. and D.T. Wigle. Medical Care and the Declining Rates of Death due to Heart Disease and Stroke. CMAJ 125. November1, 1981. pp. 953-985. 2. Current Cardiovascular Mortality; e d i t o r i a l JAMA 245 (6), February 18, 1981. p. 555. 3. Stern, M.P. The Recent Decline i n Ischemic Heart Disease M o r t a l i t y . Ann. Intern. Med. 9_1 (4). October 1979. pp. 630-640. 4. Stamler, J. Primary Prevention of Coronary Heart Disease: The Last 20 Years. Am. J. C a r d i o l . 47. March 1981. pp. 722-35. p. 730. 5. Wigle, D.T. Heart Disease Morbidity and Mortality Trends. Chronic Disease i n Canada 2_ (2). September 1981. p. 10. 6. N i c h o l l s , E.S., T. Jung, J.W. Davies. Cardiovascular Disease Mortality i n Canada. CMAJ 125. November 1981. p. 981. 7. Wigle, D.T. i b i d . p. 10. 8. Rose, G. Strategy of Prevention: Lessons from Cardiovascular Disease. B r i t . Med. J. 282. June 6, 1981. pp. 1847-51. p. 1848. 9. Primary prevention i s defined as prevention occurring before a disease state becomes established. Secondary prevention i s defined as prevention of c l i n i c a l expression of disease or of early p r e c l i n i c a l intervention. 10. For proponents of primary prevention see Walker (1983), Stamler (1981), Kuller (1981). For proponents of secondary prevention see Cobb and Alvarez (1976), Warren (1982) . 11. Stern. i b i d . 12. Wigle, D.T. i b i d . p. 10. 33 13. Epstein, Fh, Z. Pisa. International Comparisons in Ischemic Heart Disease Morbidity. In: Havlik, R.J., Reinleib, M., eds. Proceedings of the Conference on the Decline i n Coronary Heart Disease Mortality. Bethesda, MD: National Institutes of Health, 1979, p. 58 (NIH Publication No. 39-1610) as quoted by Wigle, D.T. i b i d . p. 10. 14. K u l l e r , L.H. E d i t o r i a l : Prevention of Cardiovascular Disease and Risk Factor Intervention T r i a l s . C i r c u l a t i o n 61 (1). January 1, 1980. pp. 26-28. 15. Wilhelmson, L. and others. Fibrinogen as a Risk Factor for Stroke and Myocardial Infarction. New England J. Med. 311 (8), August 23, 1984. pp. 501-5. 16. Stamler, J. i b i d . pp. 722-3. 17. Walker, W.J. Changing U.S. Lifestyle, and Declining Vascular Mortality - A Retrospective. New England J. Med. 308 (11). March 17, 1983. pp. 649-51. p. 650. 18. K u l l e r , L.H. Epidemiology of Cardiovascular Disease. Lecture series University of Minnesota. June - July 1981. 19. Stern. i b i d . p. 636. 20. Wigle, D.T. i b i d . p. 9. 21. Hosking, D.J. An Evaluation of Paramedic Services. University of Saskatchewan, Department of Social and Preventive Medicine, Saskatoon. February 1982. p. 32. 22. Stern. i b i d . 23. Mather, J.G., D.C. Morgan, N.G. Pearson, et a l . Myocardial Infarction: A Comparison Between Home and Hospital Care for Patients. Br. Med. J. 1976, 1. pp. 925-9. 24. H i l l , J.D., J.R. Hampton, J.R.A. M i t c h a l l . A Randomized T r i a l of Home-Versus-Hospital Management for Patients with Suspected Myocardial Infarction. Lancet 1978 1. pp. 837-41. 25. Crampton, R. Prehospital Advanced Cardiac L i f e Support: Evaluation of a Decade of Experience. Topics i n Emergency Medicine 1 (4). January 1980. pp. 27-35. 34 26. Morris, A.L., V. Nernberg, N.P. Roos, P. Henteleff, L. Roos. Acute Myocardial I n f a r c t i o n : Survey of Urban and Rural Hospital M o r t a l i t y . Amer. Heart Journal 105 (1). January 1983. pp. 44-53. 27. Cobb, L.A., H. Alvarez, M.K. Kopass. A Rapid Response System for Out-of-Hospital Cardiac Emergencies. Med. C l i n . N. America 6_0. 1976. pp. 283-90. 28. Cobb, L.A., R.S. Baum, H. Alvarez, W.A. Schaeffer. Resuscitation from Out-of-Hospital Ventricular F i b r i l l a t i o n : Four Years Followup. C i r c u l a t i o n 52 (Supp. I I I ) . 1975, I I I . pp. 223-35. 29. Eisenberg, M., L. Bergner, A. Hallstrom. Paramedic Programs and Out-of-Hospital Cardiac Arrest. I. Factors Associated with Successful Resuscitation. Am. J. Public Health 6_9 (1). January 1979. pp. 30-42. 30. Stern. i b i d . p. 637. 31. MRFIT Research Group. Multiple Risk Factor Intervention T r i a l . JAMA 248 (12). September 24, 1982. pp. 1465-1477. 32. MRFIT Research Group. i b i d . 33. O l i v e r , M.F. Should We Not Forget About Mass Control of Coronary Risk Factors? Lancet. July 2, 1983. pp. 37-38. 34. O l i v e r , M.F. i b i d . p. 37. 35. Walker, W.J. i b i d . 36. Stern. i b i d . p. 639. 37. Lown, B. Introduction to Cousins, N. The Healing Heart: Antidotes to Panic and Helplessness. George J. McLeod Ltd. Toronto 1983. pp. 21-22. 38. K u l l e r , L., M. Cooper, J. Pepper. Epidemiology of Sudden Death. Arch Intern Med. 129. 1972. pp. 714-19. 39. Bergner, L., M. Eisenberg. Project Restart: An Outcome Evaluation of Paramedic Programs (mimeograph). Room 508 South Tower, 506 Second Avenue, Seattle. November 1978. 35 40. Eisenberg, M.S., L. Bergner, A. Hallstrom. Epidemiology of Cardiac Arrest and Resuscitation i n a Suburban Community. JACEP 8_ (1). January 1979. pp. 2-5 41. Eisenberg, M., L. Bergner, A. Hallstrom. Epidemiology of Cardiac Arrest and Resuscitation in Children. Am. Emerg. Med. 12_ (11). November 1983. pp. 672-4. 42. K u l l e r , L.H. Epidemiology of Cardiovascular Disease. Lecture s e r i e s . University of Minnesota. June - July 1981. 36 Chapter IV The System of Emergency Medical Services 1. Components of the System A f t e r the p u b l i c a t i o n by Pantridge and Geddes of the early r e s u l t s of the B e l f a s t mobile coronary care units, the concept of layered-response out-of-hospital r e s u s c i t a t i o n systems was r a p i d l y developed and implemented i n the United States. Some of the better-known systems have been established i n Los Angeles, Miami and Seattle. A p r o l i f e r a t i o n of systems across the United States was encouraged a f t e r the 19 7 3 Emergency Medical Services Systems Act was passed. By 1979 Stern noted that "...68 of the nation's 304 emergency medical service regions are i n the "advanced" l i f e - s u p p o r t phase of a federally-sponsored program designed to achieve 2 "wall-to-wall" regional services by 1982." 3 The components of an emergency medical system are: 1) rapid (2-5 minute) response 2) r e s u s c i t a t i o n from c i r c u l a t o r y arrest 3) early therapy for the i n i t i a t i n g event ( i . e . myocardial i n f a r c t i o n , trauma and other l i f e - t h r e a t e n i n g situations) 4) d i r e c t admission to a coronary care unit 5) education of the public 6) improvement of other emergency medical services. Rapid response includes making potential users aware of the warning signs of impending cardiac arrest i n order to activate the system. This i s e s p e c i a l l y relevant to CHD patients and w i l l be discussed subsequently. Early a c t i v a t i o n of the system may be enhanced by rapid 37 access, such as i s provided by a universal emergency telephone number (911). The p r o b a b i l i t y of rapid response i s increased when a s i g n i f i c a n t proportion of c i t i z e n s are trained to perform cardiopulmonary resuscitation (CPR) or basic l i f e support (BLS). It i s also improved when first-response units are s u f f i c i e n t i n number and are located s t r a t e g i c a l l y in the area to be served. Resuscitation from c i r c u l a t o r y arrest includes three components: CPR, BLS and ACLS (see below). BLS i s defined as emergency f i r s t aid that consists of the recognition of airway obstruction, respiratory arrest and cardiac arrest and the proper application of CPR. CPR consists of the opening and maintenance of a patent airway, the provision of a r t i f i c i a l v e n t i l a t i o n by means of rescue breathing, and the provision of a r t i f i c i a l c i r c u l a t i o n by means of external cardiac compression. BLS alone i s u n l i k e l y to restore heartbeat and c i r c u l a t i o n 4 to normal. Enns et a l demonstrated det e r i o r a t i o n of rhythm i n 13 of 21 patients i n cardiopulmonary arrest (CPA) resuscitated and transported by a BLS system. In t h e i r series 5 of 10 patients found i n a tachydysrhythmia (VF and others) deteriorated to asystole during transportation to hospit a l , as d i d 8 of 9 patients found i n bradycardia or heart block. Enns and others have relegated BLS to the status of a holding action to prevent brain death u n t i l d e f i n i t i v e therapy could be i n i t i a t e d . 38 ALS or ACLS (advanced cardiac l i f e support) i s defined as BLS plus the use of adjunctive equipment to support r e s p i r a t i o n and c i r c u l a t i o n ; establishment of an intravenous l i n e , drug administration, d e f i b r i l l a t i o n and cardiac monitoring. It also includes two-way communication with the receiving i n s t i t u t i o n and physicians.^ Resuscitation from c i r c u l a t o r y arrest includes bystander CPR and rapid a r r i v a l of a first-responder unit with personnel trained i n BLS. In large metropolitan areas, f i r e f i g h t i n g units are usually more widely d i s t r i b u t e d across the community than are ambulance units. In the highly e f f i c i e n t prototype systems i t i s the f i r e units with attendants trained i n BLS that respond i n i t i a l l y . The paramedic or ACLS units are dispatched simultaneously, but because there are fewer of these units, the response times are slower. D e f i n i t i v e therapy i s begun with a r r i v a l of the ACLS unit. Removal to a h o s p i t a l with a coronary care unit and s u r g i c a l c a p a b i l i t y g completes the system. The c r u c i a l element i n EMS i s time elapsed u n t i l d e f i n i t i v e treatment can be i n i t i a t e d . Brain c e l l destruction usually begins within four minutes of cardiac arrest and a l l e f f o r t s are directed toward reaching the i n d i v i d u a l i n cardiac arrest before those four minutes have passed. A study i n elapsed time for 998 f a t a l cases of CHD from Belfast was published i n 1968.7 A l l deaths attributed to coronary artery disease occurring i n B e l f a s t from July 1965 to July 1966 39 were reviewed. The ACLS system was i n place for a b r i e f portion of the study but was judged not to have had an impact because the time was too short. Of 998 cases, 98 (9.8%) were found dead by ambulance personnel, 389 (38.9%) died e i t h e r before an ambulance was c a l l e d for, or arri v e d , 109 (10.9%) were pronounced dead on a r r i v a l at h o s p i t a l , while i n the ambulance, 305 (30.5%) were admitted and died i n hospital and 97 (9.7%) were i n hospital for other reasons and died of CHD. Overall, 596, or f u l l y 60% of the cases died out-of-h o s p i t a l . Of these, 229 were known to have survived for more than 30 minutes a f t e r onset of symptoms, 182 for more than an hour, and 14 3 survived more than two hours. The authors analyzed six c r i t i c a l time periods i n t h e i r series i n which delay i n reaching d e f i n i t i v e care might have been reduced. Data were not complete and calcu l a t i o n s were c a r r i e d out on smaller subgroups of the t o t a l 5 96 out-o f - h o s p i t a l deaths. 1) Onset of symptoms to c a l l i n g for help (GP, r e l a t i v e ) : the median time was 1 hour 17 minutes for men and 1 hour .6 minutes for women. In 20% of cases the time elapsed was more than 6 hours. 2) C a l l i n g for help to c a l l i n g ambulance: the median time was 59 minutes for men and 1 hour 2 6 minutes for women. 3) Ambulance dispatcher receives c a l l to dispatch of vehicle: the median time was 3 minutes for men and 8.5 minutes for women. The sex difference here was s i g n i f i c a n t (Pi 0.01) and unexpected. The authors suggested that the onset of symptoms was more insidious i n women and the physician was therefore less l i k e l y to stress urgency to the ambulance dispatcher. 40 4) Vehicle dispatched to a r r i v a l at patient: the median time was 8 minutes for men and 8.3 minutes for women. 5) Pickup of patient to a r r i v a l at emergency room: t h i s time period was not presented. Summary of time elapsed: 6) Ambulance dispatcher receives c a l l to admission to ward: the median time was 74 minutes for males and 88 minutes for females. 7) Onset of symptoms to admission to ward: the median time was 7 hours 52 minutes for males and 8 hours 4 0 minutes for females. In t h i s study the greatest sources of delay lay with patients and t h e i r advocates i n a c t i v a t i n g the system. In another review, Doehrman found that although half of the patients surveyed arrived at the ho s p i t a l within three Q hours of onset of symptoms, many delayed eight or more hours. Public and professional education, and possibly a universal-access emergency number might have averted a s i g n i f i c a n t proportion of these deaths. The response times of the Belfast EMS per se were not out of l i n e for 1965-66, when the ambulance procedure was "scoop and run", and not unusual for some j u r i s d i c t i o n s today, although there are d i s t i n c t d i f f erences from the best times currently being achieved. The other c r i t i c a l time period that could have been reduced to some e f f e c t was the time elapsed between a r r i v a l of the ambulance and onset of d e f i n i t i v e therapy. Had treatment been started on the spot instead of at the hospital another hour would have been saved. Bystander CPR, and first-responder BLS coupled with d e f i b r i l l a t i o n , or ACLS 41 onsite would a l l reduce t h i s time to a matter of minutes. Based on experience from large American c i t i e s i t has been estimated that one primary-response BLS unit i s required for every 50,000 people and one definitive-response ALS unit for every 125,000 - 150,000 people. One ALS unit requires a complement of 5 people including dispatcher and dr i v e r . To provide 24 hour service, 5 such teams or 25 people are required. Unless an ACLS unit can respond i n less than 10 minutes, i t w i l l not improve mortality from SCD. In King County i n 1982 the cost of one g ACLS unit serving 100,000 people was $415,000 per year. 2. Recent Modifications Bystander CPR Several studies have reported on the l i f e s a v i n g c a p a b i l i t i e s of out-of-hospital advanced l i f e support units'*'0 ^ but most were based on uncontrolled s e r i e s . Eisenberg and Tweed c a r r i e d out prospective controlled studies and Wennerblom conducted a prospective randomized controlled t r i a l of standard care vs. ACLS care for AMI i n Sweden (1982). These l a t t e r studies a l l confirmed the e a r l i e r reports that paramedic-treated patients had better survival rates than patients managed with BLS delivered by les s e r - t r a i n e d emergency medical technicians (EMT)_15,16,17 42 T a b l e l l demonstrates t h i s finding by summarizing the r e s u l t s of studies of survival to admission to or discharge from h o s p i t a l , for paramedic and EMT-treated patients. Table I I . Rates of Survival (%) for Paramedic-Treated or EMT-Treated Cases of Cardiac Arrest Study No. of Paramedic EMT Patients Admitted Discharged Admitted Dischargee % % % % Eisenberg et a l " ^ 487 39 27 17 6 19 Cobb et a l 595 44 23 20 Tweed et a l 849 — 21 4 21 Eisenberg et a l 574 22 6 V e r t e s i et a l 2 2 318 26 7 A successful outcome of resuscitation has been variously found to be associated with a short access time, short response time, location of c a l l , patients' age, and presence of ven t r i c u l a r f i b r i l l a t i o n instead of asystole or heart block. Tweed has provided an important analysis of some of the predictors of outcome, with p a r t i c u l a r emphasis on bystander CPR and ACLS u n i t s . 2 3 T a b l e III(modified from Tweed) shows rates of survival following bystander-initiated CPR. 43 Table I I I Rates of Survival (%) Following Bystander-I n i t i a t e d CPR Study Type of EMS Ver t e s i et a l Paramedic 224 30 8 EMT 98 6 1 Thompson Paramedic 316 43 21 Eisenberg Paramedic 487 23 12 Lund EMT 631 36 8 Tweed EMT 226 25 5 EMT 227 30 8 Guzy Paramedic 115 27 6 Rate of Survival (%) No. of to Discharge Patients With Bystander Without CPR Bystander CPR While bystander CPR has been shown to be associated with improved s u r v i v a l , there i s no rel a t i o n s h i p to the qual i t y of performance by the bystander. Several studies have shown that CPR s k i l l s deteriorate r a p i d l y and have v i r t u a l l y disappeared 24 one year aft e r t r a i n i n g . Furthermore, the b e n e f i c i a l e f f e c t of bystander CPR disappears i f the EMS response time i s more than f i v e minutes. "Though bystanders who attempt CPR contribute i n some way, perhaps by rapidl y summoning help, to a higher rate of s u r v i v a l , there i s no evidence that either the q u a l i t y of the CPR or even t h e 2 ^ attempt at CPR has any s i g n i f i c a n t influence." Bystander CPR has also been found to be highly p r e d i c t i v e of 44 the presence of v e n t r i c u l a r f i b r i l l a t i o n , which i s a major determinant of a successful outcome. The association has yet to be explained. The conclusion Tweed has drawn is' that while some aspect of bystander-associated CPR i s associated with improved outcome, whether i t i s the actual procedure or the a b i l i t y to recognize cardiac arrest and activate the system promptly i s not known. Vert e s i showed a synergistic e f f e c t of bystander CPR combined with ACLS. Bystander CPR did not enhance su r v i v a l when only an EMT unit responded. V e r t e s i recommended development of these two components of an EMS i n concert rather than either i n i s o l a t i o n . These s t a r t l i n g data on bystander CPR suggest, at a minimum, that except for research units, no additional resources ought to be directed toward t r a i n i n g the public i n CPR u n t i l the b e n e f i c i a l component i s i d e n t i f i e d and better understood. That i s , the present l e v e l of t r a i n i n g may be maintained.but should not be expanded. Alternatives to Paramedic Units Sixty percent of out-of-hospital cardiac arrests are caused by v e n t r i c u l a r f i b r i l l a t i o n (VF). Successful r e s u s c i t a t i o n i s more l i k e l y i f VF or s i m i l a r dysrhythmias are present. Resuscitation i s considerably less l i k e l y i f heart block or asystole are the presenting rhythms. It has 45 also been shown that VF untreated or treated with BLS alone w i l l deteriorate to asystole i n 50% or more of cases, decreasing 27 the p r o b a b i l i t y of s u r v i v a l . These features viewed i n combination suggest a new p o s s i b i l i t y : that rapid recognition of VF and application of countershock may be the most important component of pre-hospital ACLS. 2 8 This p o s s i b i l i t y was tested by Eisenberg i n suburban King County, Washington, where emergency services were being 2 9 provided s o l e l y by EMT's. In other published reports survival rates for cardiac arrest i n t h i s area were around 6%. A t r a i n i n g program was developed for EMT's which consisted of 10 hours of i n s t r u c t i o n i n CPR, arrhythmia recognition with emphasis on VF and the use of a d e f i b r i l l a t o r . The cost of the t r a i n i n g program was $40.00 per student. Apart from d e f i b r i l l a t i o n , no other ACLS technique was authorized. During the preceding two year period when only BLS services were av a i l a b l e , 4 of 100 patients i n cardiac arrest (4%) were discharged from h o s p i t a l . During one year when the BLS service was augmented by d e f i b r i l l a t i o n only,10 of 54 patients i n cardiac arrest (18%) were discharged from hospital (P<0.01). Despite some drawbacks to the study, such as non-random assignment, a retrospective control group, and possible interference i n the results by other aspects of the t r a i n i n g program, the concept remained an e x c i t i n g p o s s i b i l i t y . 30 S t u l t s and colleagues developed a prospectively c o n t r o l l e d study designed to t e s t the e f f e c t of the same two 46 l e v e l s of intervention i n much smaller communities i n r u r a l areas (average population 10,000). In 18 communities EMT's were trained i n d e f i b r i l l a t i o n . Twelve si m i l a r communities with EMT service only provided control data. The 16 hour t r a i n i n g program was delivered to EMT personnel in a l l communities, the only difference being t r a i n i n g i n d e f i b r i l l a t i o n was included for the study communities. Over a twenty-month period, 19% of patients (12 of 64) i n the study communities were discharged from hospital compared to 3% (1 of 31) i n the control communities (P<0.05). St u l t s i d e n t i f i e d several cautions i n in t e r p r e t i n g the data including the fa c t that because there are large numbers of volunteer EMT personnel i n small communities, and a low incidence of cardiac arrest, many EMT's trained i n d e f i b r i l l a t i o n might not be required to use t h e i r s k i l l s for years. He recommended a rigorous r e c e r t i f i c a t i o n schedule to prevent inappropriate a p p l i c a t i o n of d e f i b r i l l a t i o n . 31 Most recently Eisenberg and others expanded on th e i r e a r l i e r study by combining EMT personnel trained i n d e f i b r i l -l a t i o n with backup ACLS units. They compared the impact on mortality from t h i s expanded team to that of a standard EMT-paramedic team. With short response times for both levels of treatment the h o s p i t a l discharge rate was the same, 39% and 37%. However, i f the i n t e r v a l between a r r i v a l of EMT's and a r r i v a l of paramedics was longer than four minutes, s u r v i v a l i n the basic EMT-treated group was 18% and 38% 47 i n the E M T - d e f i b r i l l a t i o n group (P<0.01). Even a f t e r c o n t r o l l i n g for other variables such as age, sex and i n i t i a l response time, there was a s i g n i f i c a n t positive e f f e c t for E M T - d e f i b r i l l a t i o n . This study did not compare EMT-def i b r i l l a t i o n services to paramedic services, but rather assessed the additive benefit. The d e f i n i t i v e randomized t r i a l comparing the two treatment modes has yet to be published. In summary the following p o s s i b i l i t i e s have been examined: 1) When bystander CPR i s accompanied by EMT only and not pre-hospital ACLS, there has been no improvement i n s u r v i v a l rates (Vertesi; Tweed). 2) There i s no evidence that the quality of bystander CPR, or the attempt at bystander CPR has any s i g n i f i c a n t influence on mortality, although some feature of i t i s p r e d i c t i v e of a successful outcome (Tweed). 3) ACLS units are very c o s t l y to operate although they improve s u r v i v a l rates. Smaller communities do not have the necessary tax base to support a paramedic service ( S t u l t s ) . 4) Early d e f i b r i l l a t i o n by minimally-trained EMT personnel i s an e f f e c t i v e and r e l a t i v e l y inexpensive way of dealing with out-of-hospital cardiac arrest, p a r t i c u l a r l y in locations distant from large urban centres (Eisenberg, S t u l t s ) . 5) It may be that there are only two key determinants of s u r v i v a l ; i n i t i a t i o n of CPR i n less than 4 minutes a f t e r cardiac arrest, and early d e f i b r i l l a t i o n (Tweed). 48 Taken together, these statements suggest that for a l l but the largest c i t i e s i n Canada, an adequate EMS designed to deal with cardiac arrest may be provided by EMT-defibril-l a t i o n teams i n s u f f i c i e n t numbers and appropriate locations i n the community to be served. Bystander CPR and ACLS units may be components of the system that could be foregone u n t i l further studies have been c a r r i e d out. The most recent technological development to impinge 32 on t h i s category of patients i s the implantable cardioverter. A small (95 gram) f u l l y programmable device has been tested i n patients with recurrent v e n t r i c u l a r tachycardia (VT) who were not candidates for s u r g i c a l treatment of VT. Cardioversion required a very small shock (less than 0.5 Joules) and was well tolerated by the subjects. There were s i g n i f i c a n t d i f f i c u l t i e s i n t h i s t r i a l with d i f f e r e n t i a t i o n of arrhythmias by the cardioverter. However, i t i s possible that the next generation w i l l be able to d e f i b r i l l a t e . The 20-25% of SCD victims who are discharged from the hospital have a 50% mortality over 4 years. The main cause of death i s recurrent SCD induced by v e n t r i c u l a r f i b r i l l a t i o n . In the near future, t h i s device may s i g n i f i c a n t l y improve longterm sur v i v a l for such patients. 3. Impact of the System One of the major concerns about management of out-of-hospital cardiac arrest i s that rather than productive l i v e s 49 being saved, death i s merely being delayed a few months by means of an extremely expensive technology. Twenty to t h i r t y percent of cardiac arrest patients are currently being succ e s s f u l l y resuscitated and discharged from hospital a l i v e . However, the age of the survivors and the quantity and qu a l i t y of l i f e a f t e r discharge have been the subjects of much debate. There are some recent data on longterm survivors of out-of-hospital cardiac arrest. Eisenberg and others followed a series of patients over four years aft e r r e s u s c i t a t i o n . The i n i t i a l s eries consisted of 1567 cases of cardiac arrest of whom 557 (36%) were admitted and 302 (19%) were discharged. Of those discharged, 276 were available for longterm followup. Two hundred and f i f t y of the 276 went home; 26 had major sequelae and went to nursing homes or extended-care f a c i l i t i e s . Forty-seven percent of a group interviewed at six months post-discharge had worked either f u l l or part-time p r i o r to t h e i r a r r e s t . Thirty-four percent of t h i s group were able to resume f u l l or part-time work afte r the event. The p r o b a b i l i t y of survival at 6 months, one year, two years, three years and four years was 81, 76, 66, 55 and 49% respectively. The 49% 4-year survival rate was contrasted to an 80% s u r v i v a l rate for an age-sex-matched normal group, and a 66% rate for a group with uncomplicated myocardial i n f a r c -t i o n . The cause of death aft e r discharge was overwhelmingly 33 (89%) due to atherosclerotic heart disease. 50 Rockswold and others co l l e c t e d a series of 514 consecutive patients s u f f e r i n g out-of-hospital cardiac arrest i n Minneapolis between 1974 and 1976. Of the 514, 83 (16%) were discharged a l i v e from h o s p i t a l . Thirty-four had s i g n i f i c a n t impairment, primarily neurologic, and 49 were ambulatory, with good mental function. Of those 49. 4 7 were followed for a period of up to two years. Overall, the survival rates i n t h i s group were 85% at the end of one year and 50% at the end of two years. The majority of deaths during the followup period were attributed to SCD.3'* Cobb and others followed 234 discharged survivors of cardiac arrest for an average period of 14 months. The mean age of the group was 60 years. The survival rate was 70% at the end of one year and 59% at the end of two years. Thirty of Cobb's patients (13%), experienced recurrent SCD aft e r discharge. F i f t e e n were resuscitated from t h e i r second episode, with 10 surviving longterm, and subsequently 3 of these were resuscitated from a t h i r d episode, with one 35 longterm survivor. A l l three studies provided clear evidence that patients i n v e n t r i c u l a r f i b r i l l a t i o n (VF) i n the absence of myocardial i n f a r c t i o n experienced considerably higher mortality than patients resuscitated from VF associated with myocardial i n f a r c t i o n . In p a r t i c u l a r , patients i n VF without i n f a r c t i o n proved to be at high r i s k for recurrence of VF i n the early post-discharge phase (.17 weeks) . 51 As this high r i s k group became apparent, a search began for predictors of r i s k i n an e f f o r t to further improve s u r v i v a l rates. Lesch and Kehoe found a three-fold increase in the r i s k for SCD aft e r myocardial i n f a r c t i o n i f frequent or complex ven t r i c u l a r ectopic a c t i v i t y was present. The increased r i s k rose to s i x - f o l d i f congestive heart f a i l u r e 3 6 was added to the v e n t r i c u l a r ectopic a c t i v i t y . At present there i s no single technique with s u f f i c i e n t s e n s i t i v i t y and s p e c i f i c i t y to d i s t i n g u i s h low- arid high-risk groups, and a combination of techniques i s required. Further, the u t i l i t y of suppressing v e n t r i c u l a r ectopic a c t i v i t y , and of coronary bypass surgery remain to be demonstrated. For the present a systematic approach to management i s recommended, including a regimen of anti-arrhythmics a f t e r a complete hemodynamic and electrophysiologic review (via Holter 37 monitoring and radionuclide imaging). The newest technological advance (vide supra), the implantable cardioverter, may i n the future provide a method for reducing post-discharge mortality i n t h i s group of patients. However, i t i s s t i l l i n the very early stages of development. To summarize, about 10-20% of victims of cardiac arrest are being discharged a l i v e from hospital. The proportion sustaining s i g n i f i c a n t neurologic damage i s variable but may be as high as 40%. For those discharged without impairment, usually males i n t h e i r late f i f t i e s to late s i x t i e s , a 52 50-60% two year s u r v i v a l may be expected. Over a t h i r d of those a l i v e at 6 months w i l l be back at work. The primary cause of death among these longterm survivors i s SCD and e f f o r t s are currently being directed toward i d e n t i f y i n g high-risk subgroups and devising e f f e c t i v e interventions to prevent recurrent SCD. Crampton has reviewed data from several EMS and has expressed the res u l t s i n terms of l i v e s saved. The average was found to be 6.8 l i f e - s a v e s per 100,000. He calculated the value of a l o s t l i v e l i h o o d as worth $41,000 per 100,000 3 8 people i n 1980 d o l l a r s . If a d e f i n i t i v e care EMS can save 6.8 l i v e s per 100,000 the gross value per year of survival w i l l be about $280,000. The cost of one ACLS unit i n 39 King County, Washington i n 1979 was estimated at $275,000. If these data may be compared, they suggest a cost:benefit r a t i o of 1:1 i n the f i r s t year of s u r v i v a l . The benefits w i l l increase with each additional year that survivors work, but not a l l survivors are generating a l i v e l i h o o d . On balance, a cost:benefit r a t i o of 1:1 does l i t t l e to recommend a parame die ACLS unit. Since the impact of SCD i s undeniably/ large, however, i t w i l l be worthwhile to pursue the less costly but equally e f f e c t i v e options described i n the preceding section. 53 Chapter IV Notes 1. Pantridge, J.F., J.S. Geddes. A Mobile Intensive Care Unit i n the Management of Myocardial Infarction. Lancet 2. 1967. pp. 271-73. 2. Stern, M.P. The Recent Decline i n Ischemic Heart Disease Mortality. Ann., Intern Med. 9_1. October 1979. pp. 630-640. 3. Cobb, L.A., H. Alvarez, M.K. Kopass. A Rapid Response System for Out-of-Hospital Cardiac Emergencies. Med. Can. N. America 60 (2). March 1976. pp. 283-91. 4. Enns, J., W.A. Tweed, N. Donen. Prehospital Cardiac Rhythm: Deterioration i n a System Providing Only Basic L i f e Support. Amer. Emerg. Med. 12 (8). August 1983. pp. 478-81. 5. Webster, A.C. Evolution of Emergency Cardiac Care i n Canada. CMA Journal 117. December 17, 1977. pp. 1383-86. 6. McNally, R.H., J. Pemberton. Duration of Last Attack i n 998 Fatal Cases of Coronary Ajrtery Disease and i t s Relation to Possible Cardiac Resuscitation. B r i t Med. J. July 20, 1968. pp. 139-42. 7. Doehrman, S.R. Psycho-Social Aspects of Recovery from Coronary Heart Disease; A Review. Soc. S c i . Med. 1_1 1979. pp. 199-218. 8. Boyd, D.R. Government Administration and Funding of Emergency Medical Care Programs: Role of the Federal Government i n Proceedings of the F i r s t National Conference on the Medicolegal Implications of Emergency Medical Care. Dallas, Am. Heart assoc. 1976. pp. 85-110. 9. Eisenberg, M.S. and others. Treatment of Ventricular F i b r i l l a t i o n . JAMA 251 (13). A p r i l 6, 1984. .-pp, 1723-25, 10. V e r t e s i , L., L. Wilson, N. Glick. Cardiac Arrest: Comparison of Paramedic and Conventional Ambulance Services. Can. Med. Assoc. J. 128. 1983. pp. 809-83 11. Eisenberg, M., L. Bergner, T. Hearne. Out-of-Hospital Cardiac Arrest: A Review of Major Studies and a Proposed Uniform Reporting System. Am. J. Public Health 70. 1980. pp. 236-240. 54 12. Cobb, L., J. Werner, G. Trobaugh. Sudden Cardiac Death: A Decade's Experience with OUt-of-Hospital Resuscitation. Med. Concepts Cardiovasc. Dis. 49. 1980. pp. 31-36. 13. Rockswald, G. and others. Followup of 514 Consecutive Patients with Cardiopulmonary Arrest Outside the Hospital. J. Am. C o l l . Emerg. Physicians 8_. 1979. pp. 216-220. 14. Liberthson, P.R. and others. Prehospital V e n t r i c u l a r F i b r i l l a t i o n : Prognosis and Followup Course. N. Engl. J. Med. 29a. 1974. pp. 317-321. 15. Eisenberg, M., L. Bergner, A. Hallstrom. Paramedic Programs and Out-of-Hospital Cardiac Arrest: I. Factors Associated with Successful Resuscitation. Am. J. Publ. Health 69 (1). 1979. pp. 30-38. 16. Tweed, W.A., G. Bristow, N. Donen. Resuscitation from Cardiac Arrest: Assessment of a System Providing Only Basic L i f e Support Outside of Hospital. Can. Med. Assoc. J. 122. February 9, 1980. pp. 297-304. 17. Wennerblom, B. Early Mortality from Ischemic Heart Disease and the E f f e c t of Mobile Coronary Care. Acda Med. Scand. 1982. pp. 1-58. 18. Eisenberg, M. and others. opcit. 19. Cobb, L.A. and others. Resuscitation from Out-of-Hospital V e n t r i c u l a r F i b r i l l a t i o n : Four Years Followup. Ci r c u l a t i o n Supp. I l l 51 and 52. 1975. pp. 223-228. 20. Tweed, W.A. and others. o p c i t . 21. Eisenberg, M. and others. Management of Out-of-Hospital Cardiac Arrest: F a i l u r e of Basic Emergency Medical Technician Services. JAMA 243 (10). March 14, 1980. pp. 1049-1051. 22. Vertesi , L and others. o p c i t . 23. Tweed. opcit. 24. Tweed. opcit. 25. Tweed. opcit. p. 430 26. Vertesi , L and Others. o p c i t . 55 27. Tweed, W.A. and others. opcit. 28. Eisenberg, M. and others. Treatment of Out-of-Hospital Cardiac Arrests with Rapid D e f i b r i l l a t i o n by Emergency Medical Technicians. NEJM 302 (25) June 19,1980 1379-83. 29. Eisenberg, M. and others. JAMA 243 (10). March 14, 1980. pp. 1049-1051. opcit. 30. S t u l t s , K., D. Brown, V. Schug, J. Bean. Prehospital D e f i b r i l l a t i o n Performed by Emergency Medical Technicians i n Rural Communities. New Engl. J. Med. 310 (4). January 26, 1984. pp. 219-23. 31. Eisenberg, M., A. Hallstrom, M. Copass. Treatment of Vent r i c u l a r F i b r i l l a t i o n : Emergency Medical Technician D e f i b r i l l a t i o n and Paramedic Services. MAMA 251 (13). A p r i l 6, 1984. pp. 1723-1726. 32. Zipes, D. and others. Early Experience with an Implantable Cardioverter. New Engl. J. Med. 311 (8). August 23, 1984. pp. 485-490. 33. Eisenberg, M., A. Hallstrom, L. Bergner. Long-Term Survival After Out-of-Hospital Cardiac Arrest. New Engl. J. Med. 306 (22). June 3, 1982. pp. 1340-43. 34. Rockswold, G. and others. Followup of 514 Consecutive Patients with Cardiopulmonary Arrest Outside the Hospital. J. Amer. C o l l . Emerg. Physicians 8_ (6). June 1979. pp. 216-220. 35. Cobb, L.A., R.S. Baum, H. Alvarez and W.A. Schaffer. Resuscitation from Out-of-Hospital Ventricular F i b r i l l a t i o n : 4 Years Followup. C i r c u l a t i o n Supp. I l l 51-52. December 1975. III-223-228. 36. Lesch, M. and R.F. Kehoe. P r e d i c t a b i l i t y of Sudden Cardiac Death. New Engl. J. Med. 310 (4). January 26, 1984. pp. 255-57. 37. Myerburg, R.J. and others. Survivors of Prehospital Cardiac Arrest. JAMA 247 (10). March 12, 1982. pp. 1485-90. 38. Crampton, R. Prehospital Advanced Cardiac L i f e Support: Evaluation of a Decade of Experience. Topics i n Emergency Medicine 1_ (4). January 1980. pp. 27-34. 39. Eisenberg, M., L. Bergner, A. Hallstrom. Cardiac Resuscitation i n the Community. JAMA 241 (18) May 4, 1979. pp. 1905-7 56 Chapter V Emergency Medical Services i n Saskatoon 1. The P r o v i n c i a l Context Because health i s a p r o v i n c i a l r e s p o n s i b i l i t y , ambulance services generally emanate from p r o v i n c i a l Departments of Health and each province has d i f f e r e n t p r i o r i t i e s , d i f f e r e n t l e g i s l a t i o n and d i f f e r e n t patterns of operation. Larger municipalities within provinces have developed t h e i r l o c a l EMS beyond p r o v i n c i a l standards to meet the unique demands of c i t i e s , and t h i s has resulted i n a m u l t i p l i c i t y of structures, l e v e l s of funding and services. P r o v i n c i a l l i c e n s i n g regulations for ambulances were introduced i n Saskatchewan i n 1946. I n i t i a l l y the regulations covered equipment and vehicle s p e c i f i c a t i o n s only. In 1958 they were upgraded to address the issue of t r a i n i n g for ambulance attendants (at that time the t r a i n i n g required was a St. John's F i r s t Aid C e r t i f i c a t e ) . During the 1970's ambulance operators were struggling with r i s i n g costs, marginal p r o f i t s and the need to increase user fees. They therefore made presentations to the p r o v i n c i a l government to develop a system for i n d i r e c t p r o v i n c i a l funding of ambulance services. The Municipal Road Ambulance Program (MRAP) provided funding for ambulance services through a per capita grant to m u n i c i p a l i t i e s . The funds were derived through the Revenue-Sharing agreement between the province and 57 the m u n i c i p a l i t i e s . In several geographic areas, neighboring communities joined together to form ambulance d i s t r i c t s . Currently there are about 100 d i s t r i c t s i n the province, with 95 licensed operators. M u n i c i p a l i t i e s transfer the per capita grant to ambulance boards, which i n turn disburse the funds to the ambulance service providers."'" In Saskatoon i n 1977, the Provisional Board of Health was a new en t i t y constituted to, "formulate the objective, bylaws, organizational structure and related matters necessary to the establishment and functioning of a permanent health board capable of coordinating and integrat i n g the delivery of health care to the ' c i t i z e n s of Saskatoon and/or surrounding area." This group was asked to review the preliminary MRAP grant proposal and make recommendations to City Council. Over the following year, e f f o r t s were made by a committee of the Provisional Board of Health to bring other surrounding m u n i c i p a l i t i e s into an ambulance d i s t r i c t . In addition to th i s major recommendation to amalgamate urban and r u r a l m u n i c i p a l i t i e s into a d i s t r i c t , with a representative board, the committee also recommended: 1) that there be an exclusive contract with one operator; 2) that standards of operation be established for the contractor, to be monitored by a Technical Advisory Committee of the Ambulance D i s t r i c t Board. In 1979 fourteen m u n i c i p a l i t i e s including Saskatoon passed 58 bylaws authorizing p a r t i c i p a t i o n i n a single ambulance d i s t r i c t . The r u r a l communities were grouped into three geographic areas, and a board composed of four Saskatoon and three r u r a l representatives was formed. During the same timespan a community board was being established to guide the operations of the Saskatoon Community Health Unit, previously the Department of Health for the City of Saskatoon. The Board of the Health Unit regarded coordination of health services as part of i t s mandate, and sought and was granted the role of host agency for the Saskatoon and Area Ambulance D i s t r i c t Board (SAADB). The Health Unit has since provided administrative support for the SAADB and i n addition two in d i v i d u a l s hold cross-appointments on both 3 Boards to f a c i l i t a t e an exchange of information. Although there has not been much l a t i t u d e for l o c a l d i s c r e t i o n i n apportioning the funds provided, the SAADB since i t s inception has taken an active r o l e i n shaping l o c a l services, and has paid considerable attention to the development of the service and to measurements of q u a l i t y c o n t r o l . In 1978 a province-wide t r a i n i n q program based i n Regina was developed to upgrade the q u a l i f i c a t i o n s of the ambulance attendants. By 1980, throuqh e f f o r t s by the Saskatchewan Medical Association and the Saskatchewan Road Ambulance Association, the p r o v i n c i a l department of Continuinq Education established the Emergency Medical Technicians (EMT-1) program, with a refresher program added l a t e r . EMT-1 59 c e r t i f i c a t i o n i s conferred by a 131-hour program of i n s t r u c t i o n . When augmented by 25 hours of actual emergency experience, an Emergency Medical Assistant (EMA-1) c e r t i f i c a t e i s issued. About 300 ambulance personnel throughout the province are currently c e r t i f i e d at the EMT or EMA-1 l e v e l . Regulations currently require c i t y operators to have at l e a s t one EMT-1 on for each s h i f t . The course has not been made accessible except for those near Regina. and r u r a l personnel i n p a r t i c u l a r e i t h e r do not have the basic c e r t i f i c a t e or are unable to take the refresher i n or^er -t-o maintain th«= standard-In addition to serious d i f f i c u l t i e s with t r a i n i n g (especially when compared with the extensive program offered through the Southern Alberta I n s t i t u t e of Technology in Calgary, for example) there were other major problems with the province's emergency medical services. In 1982 the newly elected Conservative government established the Ambulance Review Committee chaired by MLA Larry Birkbeck to review the structures, standards and financing for ambulance services i n the province. The problems noted i n the Birkbeck Report were as follows: 1) l e g i s l a t i o n pertaining to ambulance services i s contained within f i v e separate acts administered by f i v e d i f f e r e n t departments of government. 2) there i s a lack of autonomy, expertise, and d i r e c t i o n among the D i s t r i c t Boards. 3) there i s no uniform system of communications and no p o l i c y 60 pertaining to a communications network. 4) funds used to support ambulance services come from a confusing mix of public and private sources including v a r i a b l e charges to the users of ambulance services. The majority of funds (57% i n 1982-83) are provided by the p r o v i n c i a l government. The recommendations of the Ambulance Review Committee were cautious but addressed a l l the foregoing issues. S p e c i f i c a l l y they included recommendations that covered the following areas: 1) with respect to p r o v i n c i a l organization,,,that a l l aspects of ambulance services be brought into Saskatchewan Health and that a dedicated administrative unit guided by a p r o v i n c i a l advisory body be established with the Department. This change has been i n i t i a t e d . The Ambulance Services Unit has been a c t i v e l y operating since 1983. 2) With respect to l e g i s l a t i o n , that Ambulance Services be covered by a single separate piece of l e g i s l a t i o n . 3) With respect to ambulance operations throughout the province, that: 3.1 the l o c a l organization remain a mix of public and p r i v a t e agencies, with consideration to be given to r e g i o n a l i z a t i o n of more speci a l i z e d services over the longterm; 3.2 that t r a i n i n g be standardized at the basic EMT-1 l e v e l and offered on a decentralized modular basis throughout the province; 61 3.3 that communication be standardized with respect to equipment and frequencies and that improved access v i a a t o l l - f r e e number or universal access number (911) be considered; 3.4 that funding be r a t i o n a l i z e d to r e f l e c t d i fferences across d i s t r i c t s i n distances t r a v e l l e d and c a l l volumes. At present the per capita grant system i s not responsive to d i f f e r e n t patterns of use. 3.5 that a variety of funding sources, including f e d e r a l , p r o v i n c i a l and municipal public sectors and the private insurance sector be encouraged to continue but that a c e i l i n g be put on the user fee to protect c i t i z e n s requiring ambulance services. 4) That public education be u t i l i z e d to improve the a b i l i t y of c i t i z e n s to respond to emergency s i t u a t i o n s . The newly established Ambulance Services Unit has been act i v e i n es t a b l i s h i n g a uniform data base derived from standardized run-report forms to be completed for every c a l l to every ambulance. The Unit i s also a c t i v e l y developing proposals for t r a i n i n g and l i c e n s i n g requirements and standards. However, i t has not been i n existence long enough to have f u l l y implemented any of i t s mandated i n i t i a t i v e s . In addition, while the run-report data are being c o l l e c t e d , analysis has not yet begun. 62 While the Ambulance Review Committee's recommendations and the work of the Ambulance Services Unit have been welcomed by the SAADB, the Board indicated that Saskatoon and area constituted a special area because i t included one of the two l a r g e s t c i t i e s i n the province. The Board accepted the Committee's recommendations as a baseline upon which they intend to b u i l d additional components related to the needs of a large metropolitan area surrounded by several r u r a l communities. The EMS service i n Saskatoon i s in a r e l a t i v e l y good p o s i t i o n with respect to data analysis because of the early i n i t i a t i v e of the SAADB to monitor quality v i a a computerized analysis of l o c a l l y designed run-reports. 6 The data have been analyzed by Feather and published i n the Annual Reports of the Saskatoon and Area Ambulance D i s t r i c t Board for the years 1980-81, 1981-82 and 1982-83. This data base i s the prime source of the information available on the operation 7 of the system i n the Saskatoon and Area D i s t r i c t . 2. The System i n Saskatoon The three most commonly observed organizational models for urban EMS include: 1) multiple private operators; 2) one operator holding an exclusive contract with the municipality or other contracting agency; 63 3) The municipality or other agency operating an o ambulance as a public service. In Saskatoon there i s a delicate balance between the f i r s t two models, with a single operator contracted by a community board, but with no municipal or p r o v i n c i a l l e g i s l a t i o n to prevent other operators from entering into competition with the contracted operator. The contracted operator, M.D. Ambulance, has worked well with the Board and has brought several features of the EMS into compliance with the recommendations of the Board over the past six years. At present the operator has three bases within the c i t y , and 11 BLS vehicles. There i s no sharing of space or communications with the F i r e Department. The r a t i o often used i n the l i t e r a t u r e for vehicle to population ca l c u l a t i o n s i s 1:50,000. One ACLS unit i s generally planned for each 100,000 - 125,000 population. Using t h i s maximum model, Saskatoon would require 4 BLS units and 1-2 ACLS units. The s t a f f of the ambulance service includes 20 f u l l t i m e and 10 parttime ambulance attendants, 4 dispatchers and 5 administrative s t a f f . The attendants are unionized. A s t r i k e over wage demands was narrowly averted i n 1981, and there i s a contingency plan i n place to cover such emergencies, which was developed by the operator in response to t h i s e a r l i e r c r i s i s . Personnel c e r t i f i c a t i o n has been upgraded i n 1984 to the 64 point where almost a l l s t a f f have EMT or EMA-1 q u a l i f i c a t i o n s . This i s the f i r s t year that on-site t r a i n i n g has been ava i l a b l e . The wages of the f u l l t i m e ambulance personnel i n the province are usually s l i g h t l y above minimum wage (around $6.00 per hour).. Because of the r e l a t i v e l y poor remuneration, s t a f f turnover i s high and i t i s rare to have a f u l l y trained complement of s t a f f who also have long f i e l d experience. In r u r a l areas the s i t u a t i o n d i f f e r s i n that most first-response teams are comprised of volunteers who are committed to remaining i n t h e i r community. The problem of turnover i s replaced i n t h i s s i t u a t i o n by the problem of providing adequate t r a i n i n g to a large cadre of volunteers. The annual budget for the BLS system described above i s about $600,000. Increasing the wages of the attendants to $12.00 an hour would bring costs to somewhat over $1 m i l l i o n . I f the vehicle-to-population r a t i o s used i n the larger systems were applied here, c a p i t a l outlay the f i r s t year would t r i p l e , and operating costs would r i s e i n proportion because of the additional costs of wages and benefits. A 911 communications system was estimated to cost $200,000 per year i n 1982 d o l l a r s and a public education/awareness campaign would also 9 contribute an additional $60,000. With respect to operators of the ambulance service the Annual Reports of the SAADB provide data on the number, geographic d i s t r i b u t i o n and type of c a l l (urgent, prompt, non-emergency or transfer, and dead). There are also data 65 on response times which have been used by the Board as a benchmark for q u a l i t y of s e r v i c e . ^ 0 Over the course of 24 hours the three s h i f t s are covered as follows: from midnight to 0730, 2 units; from 0730 to 1930, 4 units; and from 1930 to 2400, 3 units. Over a year there are about 10,000 c a l l s , 80% from within the c i t y l i m i t s . The average number of c a l l s per day has increased from 20 i n 1980-81 to 28 in 1982-83. There are more emergency c a l l s on Fridays and Saturdays (16% compared to 12-14% on other days of the week). The d i s t r i b u t i o n of emergency c a l l s throughout the day i s f a i r l y even at 5% per hour, except from 0100 to 0600 when the proportion drops to around 2%. Most e l e c t i v e transfers tend to occur during normal working hours. With respect to source of c a l l , patients and r e l a t i v e s i n i t i a t e 25-30% of c a l l s , police and f i r e 10-12% and the majority of the remainder are from hospitals (transfers) and nursing homes. About a quarter of the i n s t i t u t i o n a l c a l l s are urgent or prompt. For the c a l l s i n i t i a t e d by patients or r e l a t i o n s , no information i s available on the time i n t e r v a l between onset of symptoms and placement of c a l l . A survey of elapsed time in t h i s s i t u a t i o n might indicate i f delay i s s i g n i f i c a n t , and whether public education may be required. The d i s t r i b u t i o n of emergency c a l l s through the c i t y i s 30% from the core area and 70% from the periphery (Appendix A). Response times are best for the core area, and decrease as the 66 c i t y l i m i t s are approached. Over the past three years 40% of emergency c a l l s have been answered i n four minutes or l e s s , 50% by 5 minutes, 65% by 6 minutes and 75% by 7 minutes (Appendix B). With BLS c a p a b i l i t y only, the system's response c a p a b i l i t y i n under 4 minutes i s unlikely to be e f f e c t i v e i n dealing with cases of SCD. A prospective survey of numbers and outcomes for SCD w i l l be required, but a comparable system i n Winnipeg has been shown to produce a 5% rate of discharge from hospital."'"''" The standard for the C i t y F i r e Department i s a response time of 5 or fewer minutes. To achieve t h i s time, the c i t y has established 6 f i r e h a l l s . The Planning Department of the C i t y of Saskatoon has suggested that i f a 4 minute response time i s required for ambulance services, i t i s probable that 5-6 ambulance stations w i l l be required. This department has recommended deployment i n each of six suburban commercial complexes. These shopping and recr e a t i o n a l areas have been established i n s p e c i f i c locations i n order to provide services to units of 50,000 population. This service unit dovetails n i c e l y with the standard of one BLS vehicle to 50,000 people. 3. The Epidemiology of Cardiac Arrest i n Saskatoon The population of Saskatoon i s currently 170,000 (1984 Saskatchewan Hospital Services Plan) with about 10-11% being 67 people over the age of 65. While the c i t y i s already e x p e r i e n c i n g the "seniors boom" a n t i c i p a t e d elsewhere i n Canada over the next two decades, age standardized m o r t a l i t y r a t e s (ASMR) are comparatively low f o r the l e a d i n g causes of death. In Table IV data e x t r a c t e d from volume 3 i n the s e r i e s , M o r t a l i t y A t l a s of Canada "-Urban M o r t a l i t y , are used to rank Saskatoon w i t h other s e l e c t e d Canadian c i t i e s f o r deaths due 13 to coronary heart disease. The data are aggregated over 1973-1979 and have been drawn from m o r t a l i t y f i g u r e s f o r ICDA codes 410-413 (8th r e v i s i o n ) and ICDA codes 410-414 (9th r e v i s i o n ) . TABLE IV Age Standardized M o r t a l i t y Rates f o r CHD 1973-1979 Selected Canadian C i t i e s , by Sex ICD codes 410-413 1973-76 (8th r e v i s i o n ) ICD codes 410-414 1976-79 (9th r e v i s i o n ) MALE FEMALE SASKATOON 235.4 52.4 REGINA 300.6 69.9 ST. JOHN, N.B. 446. 0 133.5 MONTREAL 420.6 •127.2 KINGSTON 430.2 132.4 HAMILTON 353. 9 101. 9 WINNIPEG 362.4 96.1 CALGARY 289.7 76.1 EDMONTON 297. 1 77.4 VANCOUVER 322.0 82.3 WHITEHORSE 424. 0 57.7 68 It may be seen that Saskatoon had a s i g n i f i c a n t l y low mortality experience for CHD during those years. Hosking has calculated numbers of deaths of Saskatoon 1 4 residents coded ICDA 410 for the years 1980 to 1983. Table V shows for each year the t o t a l number of deaths i n Saskatoon a t t r i b u t e d to code 410 and those occurring out-of - h o s p i t a l as opposed to those occurring within hospital or i n a s i m i l a r i n s t i t u t i o n , and the average age of the patients. Table V DEATHS FROM ACUTE MYOCARDIAL INFARCTION (ICDA CODE 410) SASKATOON 198 0-83 14 From Hosking, D.J. In Hospital Total Average Out of Hospital Or I n s t i t u t i o n YEAR Deaths Age No. % ' 0 3 No. % 1980 157 78 36 23 121 77 1981 163 71 45 28 118 72 1982 233 75 54 23 179 77 1983 155 N'/A 44 28 111 72 These figures are probably conservative since they are r e s t r i c t e d to code 410, instead of codes 410-414, the usual r.ange surveyed. In addition, when Gillum and others c a r r i e d out a si m i l a r study i n Minneapolis they conducted 69 an extensive ascertainment procedure to ensure complete counting of a l l out-of-hospital deaths that ought to have been a t t r i b u t e d to these codes. They found about 8% of out-of-hospital deaths were i n c o r r e c t l y coded. 1 5 Given these two possible sources for underestimating SCD i n Saskatoon, a figure of about 60 such deaths per year i s proposed as a working average. Estimates derived from l i t e r a t u r e c i t e d previously have suggested a figure of 6 out-of-hospital cardiac arrests a year per 10,000 people (Eisenberg 1978). In a c i t y of 170,000, about 100 SCD would have been expected. If 20-30% survived to be discharged from h o s p i t a l , as happens i n c i t i e s with the most extensively developed EMS, Saskatoon might experience 2 0-30 l i v e s saved per year. With 50% mortality i n the f i r s t two to three years, about 10-15 people, mainly men i n the seventh and eighth decades would s t i l l be a l i v e more than two years after the event, and of those, about 3 to 5 would be working f u l l or part-time. However, given the actual data from Saskatoon for 1980 to 1983 and bearing in mind the s i g n i f i c a n t l y low mortality rates from CHD from 1973 to 1979, these "expected" c a l c u l a t i o n s require reduction by about one-third to one-half. The benefits of l i v e s saved have been discussed in Chapter 4. If a l i f e saved provided a benefit of about $41,000 per i n d i v i d u a l per year and i f i n Saskatoon under i d e a l circumstances 6-10 l i v e s might be saved per year, the o v e r a l l benefit would range from $240,000 to $410,000 70 (1980 d o l l a r s ) . The cost of developing the system to the point where 20-30% of SCD are discharged from hospital has been analyzed i n the foregoing section. I n i t i a l c a p i t a l outlay would have to t r i p l e and operating costs of just one ACLS unit would exceed the calculated benefits. It i s well recognized that smaller communities do not have the tax base to support systems such as those operated i n Seattle or Miami. The fact that the high mortality rates experienced i n large American c i t i e s may not be experienced i n communities i n other regions also has a s i g n i f i c a n t bearing on the argument. An adequate and affordable EMS for Saskatoon w i l l be quite d i f f e r e n t from the prototype systems. 4. A Proposal with Alternatives For any s i t u a t i o n there are three basic alternative options. F i r s t , present programs may be continued, and i n some cases, the do-nothing approach may be j u s t i f i e d . Second, present programs may be modified within the constraints of available resources to address assessed needs i n a more responsive way. Third, resources may be s h i f t e d away from present programs and put into new programs that more d i r e c t l y address the assessed need. To continue with the present program means continuing with inadequate t r a i n i n g and remuneration of s t a f f , i n e f f e c t i v e l y located ambulance s i t e s , a response time in 40% of emergencies 71 of greater than 6 minutes, and i n 60%, of greater than 4 minutes, no organized approach to first-response teams i n r u r a l areas, no standardization of communication, no public awareness programs on early warnings of impending emergency except for ongoing bystander CPR t r a i n i n g sponsored by community agencies, and f i n a l l y , no s p e c i f i c a l l y collected data on the numbers of SCD i n the D i s t r i c t or t h e i r salvage rate. This option i s unsupportable for the following reasons: 1) i t i s probably unethical to maintain current standards i n the l i g h t of minimal costs required to upgrade t r a i n i n g and improve deployment of ambulance units; 2) the treatment of the r u r a l parts of the D i s t r i c t i s inequitable; 3) there are i n e f f i c i e n c i e s b u i l t into the system which may be f a i r l y simply remedied; 4) bystander CPR i n the absence of mobile d e f i n i t i v e care may be doing harm and i s possibly not doing any good. Another a l t e r n a t i v e i s to reallocate resources away from the e x i s t i n g program i n order to begin new i n i t i a t i v e s . In t h i s instance the new i n i t i a t i v e s would probably include smoking cessation, dietary counselling and f i t n e s s campaigns. S t r i c t l y speaking t h i s may turn out to be the most e f f e c t i v e solution i n the longterm. However, the calculated b e n e f i c i a l e f f e c t s of primary prevention i n i t i a t i v e s on CHD mortality were set at one-half for white males and one-third for white 72 females. The f a i l u r e of any cl e a r , p o s i t i v e answers to emerge from the multiple r i s k factor intervention t r i a l s further detracts from the strength of t h i s option. F i n a l l y i t would almost c e r t a i n l y be p o l i t i c a l l y unacceptable to reduce e x i s t i n g services, p a r t i c u l a r l y when the present government has s i g n a l l e d i t s intent to move i n the opposite d i r e c t i o n . The f i n a l option i s to modify present programs in the l i g h t of assessed needs. The system requires better response times to i n i t i a t i o n of CPR i n both urban and r u r a l areas before any other changes are introduced. Improved time to onset of d e f i n i t i v e therapy and improved public response may also be required but further information must be gathered f i r s t . The C i t y of Saskatoon has an unusual urban planning c a p a b i l i t y i n that the neighborhood d i s t r i c t s that comprise the community are based on a gr i d compatible with census t r a c t boundaries. The age-sex population pyramid for any of the 54 neighborhood d i s t r i c t s i s known, as are standard census sociodemographic data. In the immediate future, a postal code t r a n s l a t i o n program w i l l be added to the present system which w i l l enable the City to attribute h o s p i t a l morbidity and mortality data back to neighborhood of residence. This feature w i l l permit analysis of the d i s t r i b u t i o n and concentration of target conditions across c i t y d i s t r i c t s with known population bases. It w i l l be possible within the next year to plot the d i s t r i b u t i o n of 73 SCD and other emergencies by location and time. The proposal for managing out-of-hospital cardiac arrest i n Saskatoon and area has six components: 1. Assessment of the geographic d i s t r i b u t i o n of SCD i n both the urban and r u r a l areas of the D i s t r i c t . In the c i t y t h i s may be achieved by using the program outlined above. In r u r a l area^s, a prospective survey w i l l be necessary. 2. A prospective survey of SCD incidence and salvage rates to be undertaken within the D i s t r i c t . This w i l l provide a baseline from which to r e f i n e calculations of costs and benefits. 3. A planning exercise to be undertaken regarding the number and deployment of vehicles i n the c i t y and the l o c a t i o n of first-response teams i n the r u r a l area of the D i s t r i c t . The exercise w i l l be s p e c i f i c a l l y directed toward reducing response time to four minutes or l e s s . 4 . A public awareness campaign to be i n i t i a t e d i f prospective surveys indicate that there are s i g n i f i c a n t delays between onset of symptoms and ac t i v a t i o n of the system. 5. A l l ambulance attendants to be upgraded to EMT-1 with regular r e c e r t i f i c a t i o n . 6. A p i l o t study of EMT-defibrillation to be i n i t i a t e d i n one ambulance unit for the c i t y service and i n one geographic area of the r u r a l part of the D i s t r i c t . 74 Some of these components may be undertaken simultan-eously which w i l l reduce the time required for the study. Except for the public awareness campaign and the p i l o t study of E M T - d e f i b r i l l a t i o n , resources required can come from e x i s t i n g a l l o c a t i o n s . Presumably both components with s i g n i f i c a n t costs attached w i l l be of intere s t to the p r o v i n c i a l government because of the p o s s i b i l i t y of wider a p p l i c a t i o n . The l i k e l i h o o d of funding for these two components seems reasonable. 75 Chapter V Notes 1. Saskatchewan Department of Health: Report of the Ambulance Review Committee. Towards a Comprehensive  and Integrated Ambulance Service for Saskatchewan. L. Birkbeck (Saskatchewan, 198.3. p. 3-5). 2. Report of the Provisional Board of Health. Unpublished mimeo. 19 77. 3. Slimmon, J. The History of the Saskatoon Area Ambulance  D i s t r i c t . Unpublished mimeo 19.83. SAADB Orientation Manual. 350 - 3rd Avenue N., Saskatoon. 4. Saskatchewan Health. i b i d . 5. Saskatchewan Health. i b i d . p. 35-39. 6. The run reports were designed, implemented, and monitored by Mrs. Joan Feather, the secretary to the SAADB from i t s inception to 1981. 7. Annual Reports of the Saskatoon and Area Ambulance D i s t r i c t Board 1980-1983. 350 - 3rd Avenue N. Saskatoon. 8. Matthews, V.L. Letter to the Provisional Board of Health. December 6, 1978. Saskatoon. 9. Hosking, D.J. An Evaluation of Paramedic Services February 1982. A Report to the SAADB, Saskatoon. 10. Annual Reports of the SAADB. i b i d . 11. Tweed, W.A. , G. Bristow, N. Donen. "Resuscitation from Cardiac Arrest: Assessment of a System Providing Only Basic L i f e Support Outside of Hospital. CMA Journal 122 February 9, 1980. pp 297-304. 12. Annual Report 198 3 Saskatoon Community Health Unit Saskatoon October 1984 156 p.) 13. Health and Welfare Canada. Mortality Atlas of Canada, Vol. 3 : Urban Mortality (Ottawa 1984 139 p.) 14. Hosking, D.J. i b i d . I am greatly indebted to Dr. Hosking for permitting me to use t h i s mortality information. Gillum, R.F. and others. "Sudden Death and Acute Myocardial Infarction i n a Metropolitan Area 1970-1980. New Engl. J. Med. 309^  (.22). December 1, 1983. pp. 1353 77 Chapter VI Summary and Recommendations There are several key points contained i n the material reviewed in t h i s study. F i r s t CHD i s the leading cause of death i n North America and i n the c i t y of Saskatoon. However, i n Saskatoon the rates are comparatively low. Sudden cardiac death i s numerically an important category of mortality from CHD i n much of North America, but does not appear to be as prevalent as expected i n Saskatoon. An estimate of 60 cases per year has been made for the c i t y , but f u l l y accurate data are not available. A prospective survey may be the best way to determine incidence of SCD for Saskatoon. The incidence of and mortality from CHD are de c l i n i n g s i g n i f i c a n t l y i n North America. An estimated one-third to one-half of the decline has been att r i b u t e d to primary prevention but the data are not clear enough for t h i s estimate to be unassailable. Secondary preventive measures applied optimally can salvage only about 10% of victims of CHD, and therefore do not provide a longterm solution. U n t i l further studies are done, both primary and secondary preventive measures should be maintained. With respect to EMS systems i n operation today, i t i s known that one of the major sources of delay l i e s with patients not a c t i v a t i n g the system. The importance of public awareness of the symptoms of impending collapse 78 cannot be overstressed. Although the l i f e s a v i n g c a p a b i l i t i e s associated with ACLS and bystander CPR have been well documented, i t i s not clear that ei t h e r component per se d i r e c t l y a f f e c t s s u r v i v a l . It appears now that short time to i n i t i a t i o n of CPR, and short time to d e f i n i t i v e therapy ( d e f i b r i l l a t i o n ) may be the key and may permit innovative variants on ACLS and bystander CPR. Bystander CPR i n the absence of ACLS, or without the provision of d e f i n i t i v e care i n le s s than 10 minutes,, does not improve s u r v i v a l , and may a c t u a l l y do harm. ACLS units have r a r e l y been viewed as having universal appl i c a t i o n . They cannot work i n r u r a l or remote areas, and appear to be too expensive to be supported by smaller c i t i e s and towns. Given present cost-estimates and the current mortality rates from SCD i n Saskatoon the cost benefit r a t i o for a tiered-response system including ACLS and bystander CPR i n t h i s area i s u n l i k e l y to exceed 1:1. Fortunately, there i s new evidence that scaled-down a l t e r n a t i v e s such as EMT-def i b r i l l a t i o n may produce similar benefits. The added advantage i s that EMT-defibrillation has been shown to work in at least one study in a r u r a l area. The r e l a t i v e l y few l i v e s now being saved by EMS should not be discounted. Not only are people staying healthier l a t e r i n l i f e , but there are also new technologies being developed that may enhance the longterm s u r v i v a l of these patients. 79 F i n a l l y , Saskatchewan i s undergoing a process of review and upgrading of EMS services on a province-wide basis, and the l o c a l ambulance board i s strongly committed to developing the best service possible for the resources a v a i l a b l e . The p o l i t i c a l w i l l to improve e x i s t i n g systems i s on record, as i s community support for the best affordable service. Some of the d i f f i c u l t i e s with the Saskatoon Ambulance service may be r e c t i f i e d at minimal cost. Other changes ought to be preceded by a period of l o c a l study. The questions set f o r t h i n i t i a l l y i n t h i s paper may now be answered in part. 1. A properly designed EMS can provide small gains i n terms of reducing mortality from cardiac arrest. 2. The components required to achieve t h i s reduction i n mortality may not be as c o s t l y or complex as once anticipated. They include a public education campaign, enough ambulance units i n s t r a t e g i c locations that w i l l permit BLS response i n four minutes, adequately trained and remunerated ambulance attendants (EMA-1), d e f e r r a l of consideration of ACLS, and possibly a t r i a l of E M T - d e f i b r i l l a t i o n . 3. Saskatoon and area may be able to afford the scaled-down version of the most e f f e c t i v e EMS. 4. The epidemiology of cardiac arrest i n Saskatoon appears to be d i f f e r e n t enough from published data that the f u l l y developed ACLS system i s not warranted. 80 5. CHD and cardiac arrest,not withstanding the r e l a t i v e l y low rates i n Saskatoon, remain leading causes of death i n the community. 6. There are other ways of impacting on CHD mortality that may be more e f f e c t i v e i n the long run. However, modest improvements i n our EMS should be pursued i n tandem with further development of primary prevention programs. The recommendations a r i s i n g from t h i s study are as follows: 1. Both primary and secondary preventive programs directed toward reducing mortality from out-of-hospital cardiac arrest ought to be maintained and where possible improved. 2. Public awareness of the"signs of an impending cardiac event, and appropriate response, i s one component of an EMS that requires immediate attention. 3. Notwithstanding #2 above, community-based programs to teach bystander CPR should not be expanded from t h e i r present l e v e l of a c t i v i t y u n t i l the b e n e f i c i a l feature of bystander CPR i s known. 4. Consideration by the SAADB of the components of the proposal i n Chapter V for modifying the EMS in Saskatoon and area w i l l hopefully provide material for debate and discussion. 81 BIBLIOGRAPHY Annual Reports of the Saskatoon Area Ambulance D i s t r i c t Board 1980-1983. 350 - 3rd Avenue N., Saskatoon. Chambers, L.W., C. Woodward, C. Dok. Guide to Health Needs Assessment: A Critique of Available Sources of Health and Health Care Information. McMaster University Faculty of Health Sciences (mimeograph). November 1979. p. 3. Crampton, R. Prehospital Advanced Cardiac L i f e Support: Evaluation of a Decade of Experience. Topics i n Emergency Medicine 1 (4). January 1980. pp. 27-35. Current Cardiovascular Mortality; e d i t o r i a l JAMA 245 (6). February 18, 1981. p. 555. Cobb, L.A., R.S. Baum, H. Alvarez, W.A. Schaeffer. Resuscitation from Out-of-Hospital Ventricular F i b r i l -l a t i o n : Four Years Followup. C i r c u l a t i o n 5_2 (Supp. I I I ) . 1975, I I I . pp. 223-35. Cobb, L., J. Werner, G. Trobaugh. Sudden Cardiac Death: A Decade's Experience with Out-of-Hospital Resuscitation. Med. Concepts Cardiovasc. Dis. 4_9. 1980. pp. 31-36. Enns, J., W.A. Tweed, N. Donen. Prehospital Cardiac Rhythm: Deterioration in a System Providing Only Basic L i f e Support. Amer. Emerg. Med. 12 (8). August 198 3. pp. 478-81. Eisenberg, M.S., L. Bergner, A. Hallstrom. Epidemiology of Cardiac Arrest and Resuscitation i n a Suburban Community. JACEP 8 (1). January 1979. pp. 2-5. Eisenberg, M., L. Bergner, A. Hallstrom. Cardiac Resuscitation i n the Community. JAMA 241 (18). May 4, 1979. pp. 1905-7. Eisenberg, M., L. Bergner, A. Hallstrom. Epidemiology of Cardiac Arrest and Resuscitation in Children. Am. Emerg. Med. 12 (11). November 1983. pp. 672-4. Eisenberg, M., A. Hallstrom, L. Bergner. Long-Term Survival After Out-of-Hospital Cardiac Arrest. New Engl. J. Med. 306 (22). June 3, 1982. pp. 1340-43. Eisenberg, M. and others. Management of Out-of-Hospital Cardiac Arrest: F a i l u r e of Basic Emergency Medical Technician Services. JAMA 243 (10). March 14, 1980. pp. 1049-1051. 82 Eisenberg, M., L. Bergner, A. Hallstrom. Paramedic Programs and Out-of-Hospital Cardiac Arrest. I. Factors Associated with Successful Resuscitation. Am. J. Public Health 69 (1). January 1979. pp. 30-42. Eisenberg, M., A. Hallstrom, M. Copass. Treatment of Ventricular F i b r i l l a t i o n : Emergency Medical Technician D e f i b r i l l a t i o n and Paramedic Services. JAMA 251 (13). A p r i l 6, 1984. pp. 1723-1726. Gillum, F.R. and others. "Sudden Death and Acute Myocardial Infarction i n a Metropolitan Area 1970-1980. New Engl. J. Med. 309 (22). December 1, 1983. pp. 1353-9. Health and Welfare Canada. Mortality Atlas of Canada, Vol.  3 : Urban Mortality (Ottawa 1983, 139 p.). H i l l , J.D., J.R. Hampton, J.R.A. M i t c h a l l . A Randomized T r i a l of Home-Versus-Hospital Management for Patients with Suspected Myocardial Infarction. Lancet 1978 1. pp. 837-41. Hosking, D.J. An Evaluation of Paramedic Services. University of Saskatchewan, Department of Social and Preventive Medicine, Saskatoon. February 1982. p. 32. K u l l e r , L., M. Cooper, J. Pepper. Epidemiology of Sudden Death. Arch Intern Med. 129. 1972. pp. 714-19. Kul l e r , L.H. E d i t o r i a l : Prevention of Cardiovascular Disease and Risk Factor Intervention T r i a l s . C i r c u l a t i o n 61 (1). January 1, 1980. pp. 26-28. Lesch, M. and R.F. Kehoe. P r e d i c t a b i l i t y of Sudden Cardiac Death. New Engl. J. Med. 310 (4). January 26, 1984. pp. 255-57. Liberthson, P.R..and others. Prehospital Ventricular F i b r i l l a t i o n : Prognosis and Followup Course. N. Engl. J. Med. 291. 1974. pp. 317-321. Lown, B. Introduction to Cousins, N. The Healing Heart:  Antidotes to Panic and Helplessness. George J. McLeod Ltd. Toronto 1983. pp. 21-22. Lown, B. "Sudden Cardiac Death: The Major Challenge Facing Contemporary Cardiology." Amer. J. Cardiol. 43. February 1979. pp. 313-28. p. 313. 83 Mather, J.G., D.C. Morgan, N.G. Pearson, et a l . Myocardial In f a r c t i o n : A Comparison Between Home and Hospital Care for Patients. Br. Med. J. 1976, 1. pp. 925-9. McNally, R.H., J. Pemberton. Duration of Last Attack in 998 F a t a l Cases of Coronary Artery Disease and i t s Relation to Possible Cardiac Resuscitation. B r i t . Med. J. July 20, 1968. pp. 139-42. Morgan, P.P. and D.T. Wigle. Medical Care and the Declining Rates of Death Due to Heart Disease and Stroke. CMAJ 125. November 1, 1981. pp. 953-985. Morris, A.L., V. Nernberg, N.P. Roos, P. Henteleff, L. Roos. Acute Myocardial Infarction: Survey of Urban and Rural Hospital Mortality. Amer. Heart Journal 105 (1). January 1983. pp. 44-53. MRFIT Research Group. Multiple Risk Factor Intervention T r i a l . JAMA 248 (12). September 24, 1982. pp. 1465-1477. Myerburg, R.J. and others. Survivors of Prehospital Cardiac Arrest. JAMA 2£7 (10). March 12, 1982. pp. 1485-90. Neighborhood P r o f i l e s . City of Saskatoon Planning Department. May 1984. p. 54. N i c h o l l s , E.S., T. Jung, J.W. Davies. Cardiovascular Disease Mo r t a l i t y i n Canada. CMAJ 125. November 1981. P. 981. Oliver, M.F. Should We Not Forget About Mass Control of Coronary Risk Factors? Lancet. July 2, 1983. pp. 37-38. Pantridge, J.F., J.S. Geddes. "A Mobile Intensive Care Unit i n the Management of Myocardial Infarction." Lancet 2. 1967. pp. 271-273. Report of the Provisional Board of Health. Unpublished mimeo. (Saskatoon, 350 - 3rd Avenue N. 1977). Rockswald, G. and others. Followup of 514 Consecutive Patients with Cardiopulmonary Arrest Outside the Hospital. J. Am. C o l l . Emerg. Physicians 8_. 1979. pp. 216-220. Rose, G. Strategy of Prevention: Lessons from Cardiovascular Disease. B r i t . Med. J. 282. June 6, 1981. pp. 1847-51. p. 1848. 84 Saskatchewan Department of Health: Report of the Ambulance Review Committee. Towards a Comprehensive and Integrated  Ambulance Service for Saskatchewan. L. Birkbeck (Saskatchewan, 1 9 8 3 . pp. 3 - 5 ) . Slimmon, J. The History of the Saskatoon Area Ambulance D i s t r i c t . Unpublished mimeo 1 9 8 3 . SAADB Orientation Manual. 350 - 3 r d Avenue N., Saskatoon. Stamler, J. Primary Prevention of Coronary Heart Disease: The Last 20 Years. Am. J. Cardiol. 4J7. March 1 9 8 1 . pp. 7 2 2 - 3 5 . p. 7 3 0 . Stern, M.P. The Recent Decline i n Ischemic Heart Disease M o r t a l i t y . Ann. Intern. Med. 9_1 ( 4 ) . October 1 9 7 9 . pp. 6 3 0 - 6 4 0 . S t u l t s , K., D. Brown, B..Schug., J. Bean. Prehospital D e f i b r i l l a t i o n Performed by Emergency Medical Technicians i n Rural Communities. New Engl. J. Med. 310 ( 4 ) . January 2 6 , 1 9 8 4 . pp. 2 1 9 - 2 3 . V e r t e s i , L. , L. Wilson, N. Glick. Cardiac Arrest: Comparison of Paramedic and Conventional Ambulance Services. Can. Med. Assoc. J. 1 2 8 . 1 9 8 3 . pp. 8 0 9 - 8 3 . Walker, W.J. Changing U.S. L i f e s t y l e and Declining Vascular Mor t a l i t y - A Retrospective. New Engl. J. Med. 308 ( 1 1 ) . March 1 7 , 1 9 8 3 . pp. 6 4 9 - 5 1 . p. 6 5 0 . Warren, J.V. "Delivery System for Emergency Cardiac Care: The Medical Plan of Action." Amer. J. Car d i o l . 5 0 . August 1 9 8 2 . pp. 3 7 0 - 7 2 . p. 3 7 0 . Webster, A.C. Evolution of Emergency Cardiac Care i n Canada. CMA Journal 1 1 7 . December 1 7 , 1 9 7 7 . pp. 1 3 8 3 - 8 6 . Wigle, D.T. Heart Disease Morbidity and Mortality Trends. Chronic Disease i n Canada 2_ ( 2 ) . September 1 9 8 1 . p. 1 0 . Zipes, D. and others. Early Experience with an Implantable Cardioverter. New. Engl. J. Med. 311 ( 8 ) . August 2 3 , 1 9 8 4 . pp. 4 8 5 - 4 9 0 . SASKATOON AREA AMBULANCE DISTRICT CITY OF SASKATOON ONLY Figure 3: Pick-up Locations f o r Emergency c a l l s (Codes 3 and 4) Legend: • No c a l l s , or less than 3 percent of total c a l l s 3 . 0 - 5.9 percent 6 . 0 - 8 .9 percent - 11.7 percent I ' l l , - ! , - 1 ' 1 : Scale: metric 1:50,000 Grid: 1 square mile APPENDIX A 1,7if.I .^jv• vJ 1 r j i?flifti.fti "It. i I if -• ^ J i i t 3 •1 ^ IiT> '-••vr» •'• \ . J SASKATOON AREA AMBULANCE DISTRICT CITY OF SASKATOON ONLY Figure 5" Legend: Proportion of Emergency C a l l s (Codes 3 & 4) for which Response Time Exceeded Six Minutes 0 - 39 percent 4C - 59 percent 60 - 79 percent 80 - 100 percent Scale: metric 1 :50,000 Grid: 1 sinmre mile '^•'0". --Vn j's?1 ,:ir;;>. : m i.i.u.i t ^ J s f! v ^ ~ ' T r w ' r 4 ! ' . . i.lJui.l.LI r / / o n ! i : : a 1 » ' 11 i • , f i t ft h*&m*M //>. . I S . !.«> i ,/ APPENDIX B if iMrJjX, 1 "I l -\ If. « IJ f j i if I l i t I! I . f ! h;i ' . ' . C O ( : , V < i; i i • j ' Y ' . ! l « I I ? : I1 11 TIT. U ^ ^ : . j y » - . y ^ S f e ^ i £ \ X- ' > 

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