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Effect of age on prehospital cardiac resuscitation outcome
Effect of Age on Prehospital Cardiac Resuscitation Outcome RICHARD C. WUERZ, MD, C. JAMES HOLLIMAN, MD, STEVEN A. MEADOR, MD, MPH, GREGORY E. SWOPE, EMT-P, ROBERT BALOGH, MD* To compare resuscitation outcomes in elderly and younger prehospital cardiac arrest victims, we used a retrospective case series over 5 years in rural advanced life support (ALS) units and a University hospital base station. Participants included 563 adult field resuscitations. Excluded were patients with noncardiac etiologies, those less than 30 years old, and those with unknown initial rhythms. Patients were grouped by age. Return of spontaneous circulation (ROSC) and survival to hospital discharge were compared by Yates' chi-square test. ALS treatment of cardiac arrest was by regional protocols and on-line physician direction. Sixty percent (320/532) of patients were over 65 years old. The proportion with initial rhythm ventricular fibrillation (VF) was 50% in the elderly and 48% in younger patients. ROSC was achieved in 18% of elderly and 16% of younger patients; survival was 4% among the elderly and 5% for younger patients. The oldest survivor was 87 years old. Most survivors were discharged, in good Cerebral Performance Categories. There was no difference in outcome by age group when initial cardiac rhythm was considered. Early cardiopulmonary resuscitation (CPR) and ALS and initial rhythm VF were associated with the best resuscitation success. Age has less effect on resuscitation success than other well-known factors such as early CPR and ALS. Advanced age alone should probably not deter resuscitation attempts. (Am J Emerg Med 1995;13:389-391. Copyright © 1995 by W.B. Saunders Company) The elderly are a rapidly increasing segment of the US population, 1 and their utilization of emergency care is substantial. 2'3 The utility of many "end of life" interventions is undergoing renewed scrutiny because of ethical and financial constraints, 4 and some authors have recommended withholding resuscitation based on age alone. 5 Is it appropriate to consider age in the decision to initiate or terminate cardiac resuscitation? To answer this question, one must have information on the effectiveness of resuscitation in different age groups. The objective of this study was to compare resuscitation outcomes in elderly and younger victims of prehospital cardiac arrest.
METHODS The setting for this study is a rural two-tiered emergency medical service (EMS) system serving approximately 150,000 persons. The area is served by 911 telephone service. Three advanced life support (ALS) services provided care to cardiac arrest victims during the study period. The units are staffed by emergency medical technician (EMT) paramedics and registered nurses who receive off-line medical direction and continuingeducation from the University Hospital at which the authors are emergency medicine faculty. Basic life support (BLS) services are provided by numerous independent entities, most of whom are staffed by volunteers trained at the EMTbasic level. BLS units arrive first in 80% of cardiac arrest cases, but did not have automated defibrillators available during the time of the study. ALS crews operated under standing orders protocols based on the American Heart Association's 1986 Cardiopulmonary Resuscitation-Advanced Cardiac Life Support (CPR-ACLS) Guidelines. Defibrillation, endotracheal intubation, and intravenous medications (epinephrine, atropine, and lidocaine) were included in the standing orders. In addition, on-line medical direction by emergency physicians was obtained for further orders, unless radio communications failed. This was a retrospective case series from 1987 through 1991. Data was abstracted from an established prehospital care database containing run report and hospital outcome information on approximately 30,000 ALS patients, including 1,085 cardiac arrest cases. Cases excluded were those with no prehospital resuscitation attempt (n = 426), noncardiac etiologies (n = 76), those less than 30 years old (n = 20), and those with unknown initial rhythm (n = 31). Patients were grouped according to age. The elderly group included those over 65 years old, whereas the younger group included those from 30 to 65 years old. Outcomes were reported according to the recommendations of the Utstein consensus conference. 6 Survival was defined as hospital discharge. Groups were compared by the Yates' chi-square test with a = 0.05.
RESULTS From the Center for Emergency Medicine, The Milton S. Hershey Medical Center, The Pennsylvania State University, Hershey, PA, and *Good Samaritan Hospital, 4th and Walnut St, Lebanon, PA. Manuscript received July 14, 1994; revision accepted August 13, 1994. Presented in part at the Society for Academic Emergency Medicine Annual Meeting, San Francisco, CA, May 1993, and the 8th World Congress of Emergency and Disaster Medicine, Stockholm, Sweden, June 1993. Address reprint requests to Dr Wuerz, Center for Emergency Medicine, Milton S. Hershey Medical Center, Pennsylvania State University, Hershey, PA 17033. Key Words: Emergency medical services, prehospital care, cardiac arrest, cardiopulmonary resuscitation, advanced life support, ventricular fibrillation, elderly. Copyright © 1995 by W.B. Saunders Company 0735-6757/95/1304-000255.00/0
Figure 1 summarizes the results. Return of spontaneous circulation (ROSC) was achieved in 17% (91/532) of the patients; 18% (59/320) of the elderly, and 16% (32/202) of the younger patients (P value was not significant). Survival to hospital discharge occurred in 5% (28/532) of patients; 5% (16/320) of the elderly, and 6% (12/202) of the younger patients (P value was not significant). Of the 28 survivors, 24 were discharged home. There were no significant differences between groups for descriptive characteristics or initial cardiac rhythms (Table 1). Ventricular fibrillation (VF) has more favorable outcomes than either asystole or pulseless electrical activity; however, within each rhythm group, age does not appear to affect outcome. The mean - SD ages of the groups were 75 _ 7 (elderly) and 55 --- 9 (younger). The groups' median -+
389
390
AMERICAN JOURNAL OF EMERGENCY MEDICINE • Volume 13, Number 4 • July 1995
TABLE1. Comparison of Groups
150,000 population 1085 Confirmed cardiac arrests considered for resuscitation
[
non-cardiac etiology
I
659
no resuscitation attempted
L
resuscitations attempted
532
Age > 3 0 , / c a r d i a c etiology/ known initial rhythm
91(16%)
died in field
died in ED
died in hospital
ROSC
r
74 Admitted
28(5%) Survival
other HCF
24 home
FIGURE 1. Utstein-style description of cardiac arrests, 1987 to 1991. interquartile ranges were 74 (69 to 80, elderly) and 59 (50 to 61, younger). Factors associated with resuscitation success are summarized (Table 2). Initial rhythm, early CPR, and ALS are associated with successful resuscitation, but age is not a significant independent factor. Neurologic outcome data was available for 19 of the 28 discharged patients. The Pittsburgh-Glascow Cerebral Performance Categories 6 were as follows: category 1:9 elderly, 7 younger; category 2: none; category 3:1 elderly; category 4 : 2 younger. DISCUSSION
Our study found that elderly and younger patients have comparable resuscitation outcomes. We corroborate previous research 7-9 that the major determinants of resuscitation success are initial rhythm (VF), early CPR, and early defibrillation. In our EMS system, the elderly were equally
ALS call-response interval Witnessed collapse CPR within 4 min ALS within 10 min VF ROSC Survival Asystole ROSC Survival Puiseless electrical activity ROSC Survival
Elderly (n = 320)
Younger (n = 202)
9 +-- 5 min 191 (59%) 135 (42%) 135 (42%) 152 (48%) 41 (26%) 13 (8%) 97 (31%) 7 (7%) 0 (0%) 71 (21%) 11 (15%) 1 (1%)
9 ± 5 min 119 (59%) 79 (39%) 81 (40%) 101 (50%) 19 (19%) 9 (9%) 75 (37%) 7 (9%) 1 (1%) 26 (13%) 6 (23%) 0 (0%)
P values were not significant for all comparisons.
likely to have a witnessed arrest, to be found in ventricular fibrillation, and to receive timely CPR and ALS. Although our rural system's overall cardiac arrest survival rate is only 5% (9% for VF), our results compare favorably with large urban EMS systems 1°'11 which report a 1% to 2% survival. Furthermore, our neurologic outcomes are encouraging, with most survivors (regardless of age) being discharged home. We conclude that advanced age alone should not deter resuscitation attempts. Previous data on the effect of age on cardiac arrest outcomes has generally been discouraging. Weaver et al9 found that age did not influence initial resuscitation, but did negatively affect hospital survival. Murphy et a112found that only 0.8% of elderly out-of-hospital arrest victims survived and called resuscitation of the elderly "futile." Tresch et al1344 found that the elderly had a substantially lower survival, but nonetheless recommended resuscitation attempts regardless of age. Fusgen and Summa ~5 found that survival among the elderly was only V3 as high as in the younger victim. They also surveyed survivors about quality of life and whether they wished to be resuscitated again; most did not. Other studies have been more positive. The Belgian Cerebral Resuscitation Study 16 found that resuscitation and 2-week survival were equivalent in four age groups. Like both Weaver et al and Tresch et al, the Belgian study found a trend for higher in-hospital postresuscitation mortality related to decreased physiologic reserve in the elderly. InvesTABLE2. Determinants of Resuscitation Success
Age >65 (n = 320)* Age <65 (n = 202)* VF (n = 258) Other rhythms (n = 274) CPR within 4 min (n = 204) CPR after 4 min (n = 348) ALS within 10 min (n = 214) ALS after 10 min (n = 317)
No. of ROSC
No. of Survivals
59 (18%) 32 (16%) 60 (23%) 31 (11%) 52 (24%) 50 (14%) 59 (28%) 43 (12%)
16 (5%) 12 (6%) 22 (9%) 2 (1%) 20 (10%) 5 (1%) 23 (11%) 5 (1%)
* P values were not significant for age comparisons; all others, P < .05.
WUERZ ET AL • AGE AND CARDIAC RESUSCITATION
tigators in Seattle 17 found equal resuscitation outcomes among elderly and younger victims of out-of-hospital cardiac arrest. They also found that, contrary to many fears of persistently vegetative survivors, most patients were discharged. Bonnin et a118 and Safar et a119 reported abstracts with similar results. Our data has several limitations. The numbers of survivors are low, limiting the ability to detect differences between groups. Our EMS system did not use automatic external defibrillation by EMTs, and we have a relatively long ALS response interval because of the rural nature of our service area. It is possible that earlier defibrillation might improve ROSC more than survival, thereby resulting in a difference between age groups as found by Weaver et al. The age groupings we used were arbitrary, and others have used 70 years as a cutoff. However, this was part of our a priori study design, and 65 years is the most widely recognized definition of the elderly age group. Post hoc analysis of our data using the 70-year-old age grouping showed similar results.
REFERENCES 1. Schneider EL, Geraimik JM: The aging of America. JAMA 1990;263:2335-2340 2. Strange GR, Chen EH, Sanders AB: Use of emergency departments by elderly patients: Projections from a multicenter data base. Ann Emerg Med 1992;21:819-824 3. Meador SA: Age-related utilization of advanced life support services. Prehosp Disaster Med 1991 ;6:9-14 4. Murphy DJ: Should emergency physicians make decisions about futility. Med Ethics Phys 1992;7:1-4 5. Baer LS: Cardiopulmonary resuscitation after age 65. Am J Cardiol 1979;43:1065 6. Cummins RO, Chamberlain DA, Abramson NS, et al: Recommended guidelines for uniform reporting of data from outof-hospital cardiac arrest: The Utstein Style. Ann Emerg Med 1991 ;20:861-874
391
7. Eisenberg MS, Horwood BT, Cummins RO, ReynoldsHaertle R, Hearne TR: Cardiac arrest and resuscitation: A tale of 29 cities. Ann Emerg Med 1990;19:179-186 8. Niemann JT: Cardiopulmonary resuscitation. N Engl J Med 327:1075-1080, 1992 9. Weaver WD, Cobb LA, Hallstrom AP, et al: Factors influencing survival after out-of-hospital cardiac arrest. J Am Coil Cardiol 1986;7:752-757 10. Becker LB, Ostrander MP, Barrett J, Kondos GT: Outcome of CPR in a large metropolitan area--Where are the survivors? Ann Emerg Med 1991;20:355-361 11. Lombardi G, Gallagher EJ, Gennis P: Outcome of out-ofhospital cardiac arrest in New York City--The pre-hospital arrest survival evaluation (PHASE) study. JAMA 1994;271:678-683 12. Murphy DJ, Murray AM, Robinson BE, et al: Outcomes of cardiopulmonary resuscitation in the elderly. Ann Intern Med 1989;111:199-205 13. Tresch DD, Thakur RK, Hoffmann RG, et al: Should the elderly be resuscitated following out-of-hospital cardiac arrest? Am J Med 1989;86:145-150 14. Tresch DD, Thakur R, Hoffmann RG, et al: Comparison of outcome of resuscitation of out-of-hospital cardiac arrest in persons younger and older than 70 years of age. Am J Cardio11988; 61:1120-1122 15. Fusgen L, Summa JD: How much sense is there in an attempt to resuscitate an aged person? Gerontology 1978;24: 37-45 16. Van Hoeyweghen RJ, Bossaert LL, Mullie A, et al: Survival after out-of-hospital cardiac arrest in elderly patients. Ann Emerg Med 1992;21:1179-1183 17. Longstreth WT, Cobb LA, Fahrenbruch CE, Copass MK: Does age affect outcomes of out-of-hospital cardiopulmonary resuscitation? JAMA 1990;264:2109-2110 18. Bonnin MJ, Pepe PE, Clark PS: Survival prognosis for the elderly after out-of-hospital cardiac arrest. Ann Emerg Med 1989;14:469 19. Safar P, Abramson N, Detre K: Old age does not negate good outcome after cardiac arrest (CA) and CPR. Resuscitation 1989;17:$133 (suppl)
METHODS The setting for this study is a rural two-tiered emergency medical service (EMS) system serving approximately 150,000 persons. The area is served by 911 telephone service. Three advanced life support (ALS) services provided care to cardiac arrest victims during the study period. The units are staffed by emergency medical technician (EMT) paramedics and registered nurses who receive off-line medical direction and continuingeducation from the University Hospital at which the authors are emergency medicine faculty. Basic life support (BLS) services are provided by numerous independent entities, most of whom are staffed by volunteers trained at the EMTbasic level. BLS units arrive first in 80% of cardiac arrest cases, but did not have automated defibrillators available during the time of the study. ALS crews operated under standing orders protocols based on the American Heart Association's 1986 Cardiopulmonary Resuscitation-Advanced Cardiac Life Support (CPR-ACLS) Guidelines. Defibrillation, endotracheal intubation, and intravenous medications (epinephrine, atropine, and lidocaine) were included in the standing orders. In addition, on-line medical direction by emergency physicians was obtained for further orders, unless radio communications failed. This was a retrospective case series from 1987 through 1991. Data was abstracted from an established prehospital care database containing run report and hospital outcome information on approximately 30,000 ALS patients, including 1,085 cardiac arrest cases. Cases excluded were those with no prehospital resuscitation attempt (n = 426), noncardiac etiologies (n = 76), those less than 30 years old (n = 20), and those with unknown initial rhythm (n = 31). Patients were grouped according to age. The elderly group included those over 65 years old, whereas the younger group included those from 30 to 65 years old. Outcomes were reported according to the recommendations of the Utstein consensus conference. 6 Survival was defined as hospital discharge. Groups were compared by the Yates' chi-square test with a = 0.05.
RESULTS From the Center for Emergency Medicine, The Milton S. Hershey Medical Center, The Pennsylvania State University, Hershey, PA, and *Good Samaritan Hospital, 4th and Walnut St, Lebanon, PA. Manuscript received July 14, 1994; revision accepted August 13, 1994. Presented in part at the Society for Academic Emergency Medicine Annual Meeting, San Francisco, CA, May 1993, and the 8th World Congress of Emergency and Disaster Medicine, Stockholm, Sweden, June 1993. Address reprint requests to Dr Wuerz, Center for Emergency Medicine, Milton S. Hershey Medical Center, Pennsylvania State University, Hershey, PA 17033. Key Words: Emergency medical services, prehospital care, cardiac arrest, cardiopulmonary resuscitation, advanced life support, ventricular fibrillation, elderly. Copyright © 1995 by W.B. Saunders Company 0735-6757/95/1304-000255.00/0
Figure 1 summarizes the results. Return of spontaneous circulation (ROSC) was achieved in 17% (91/532) of the patients; 18% (59/320) of the elderly, and 16% (32/202) of the younger patients (P value was not significant). Survival to hospital discharge occurred in 5% (28/532) of patients; 5% (16/320) of the elderly, and 6% (12/202) of the younger patients (P value was not significant). Of the 28 survivors, 24 were discharged home. There were no significant differences between groups for descriptive characteristics or initial cardiac rhythms (Table 1). Ventricular fibrillation (VF) has more favorable outcomes than either asystole or pulseless electrical activity; however, within each rhythm group, age does not appear to affect outcome. The mean - SD ages of the groups were 75 _ 7 (elderly) and 55 --- 9 (younger). The groups' median -+
389
390
AMERICAN JOURNAL OF EMERGENCY MEDICINE • Volume 13, Number 4 • July 1995
TABLE1. Comparison of Groups
150,000 population 1085 Confirmed cardiac arrests considered for resuscitation
[
non-cardiac etiology
I
659
no resuscitation attempted
L
resuscitations attempted
532
Age > 3 0 , / c a r d i a c etiology/ known initial rhythm
91(16%)
died in field
died in ED
died in hospital
ROSC
r
74 Admitted
28(5%) Survival
other HCF
24 home
FIGURE 1. Utstein-style description of cardiac arrests, 1987 to 1991. interquartile ranges were 74 (69 to 80, elderly) and 59 (50 to 61, younger). Factors associated with resuscitation success are summarized (Table 2). Initial rhythm, early CPR, and ALS are associated with successful resuscitation, but age is not a significant independent factor. Neurologic outcome data was available for 19 of the 28 discharged patients. The Pittsburgh-Glascow Cerebral Performance Categories 6 were as follows: category 1:9 elderly, 7 younger; category 2: none; category 3:1 elderly; category 4 : 2 younger. DISCUSSION
Our study found that elderly and younger patients have comparable resuscitation outcomes. We corroborate previous research 7-9 that the major determinants of resuscitation success are initial rhythm (VF), early CPR, and early defibrillation. In our EMS system, the elderly were equally
ALS call-response interval Witnessed collapse CPR within 4 min ALS within 10 min VF ROSC Survival Asystole ROSC Survival Puiseless electrical activity ROSC Survival
Elderly (n = 320)
Younger (n = 202)
9 +-- 5 min 191 (59%) 135 (42%) 135 (42%) 152 (48%) 41 (26%) 13 (8%) 97 (31%) 7 (7%) 0 (0%) 71 (21%) 11 (15%) 1 (1%)
9 ± 5 min 119 (59%) 79 (39%) 81 (40%) 101 (50%) 19 (19%) 9 (9%) 75 (37%) 7 (9%) 1 (1%) 26 (13%) 6 (23%) 0 (0%)
P values were not significant for all comparisons.
likely to have a witnessed arrest, to be found in ventricular fibrillation, and to receive timely CPR and ALS. Although our rural system's overall cardiac arrest survival rate is only 5% (9% for VF), our results compare favorably with large urban EMS systems 1°'11 which report a 1% to 2% survival. Furthermore, our neurologic outcomes are encouraging, with most survivors (regardless of age) being discharged home. We conclude that advanced age alone should not deter resuscitation attempts. Previous data on the effect of age on cardiac arrest outcomes has generally been discouraging. Weaver et al9 found that age did not influence initial resuscitation, but did negatively affect hospital survival. Murphy et a112found that only 0.8% of elderly out-of-hospital arrest victims survived and called resuscitation of the elderly "futile." Tresch et al1344 found that the elderly had a substantially lower survival, but nonetheless recommended resuscitation attempts regardless of age. Fusgen and Summa ~5 found that survival among the elderly was only V3 as high as in the younger victim. They also surveyed survivors about quality of life and whether they wished to be resuscitated again; most did not. Other studies have been more positive. The Belgian Cerebral Resuscitation Study 16 found that resuscitation and 2-week survival were equivalent in four age groups. Like both Weaver et al and Tresch et al, the Belgian study found a trend for higher in-hospital postresuscitation mortality related to decreased physiologic reserve in the elderly. InvesTABLE2. Determinants of Resuscitation Success
Age >65 (n = 320)* Age <65 (n = 202)* VF (n = 258) Other rhythms (n = 274) CPR within 4 min (n = 204) CPR after 4 min (n = 348) ALS within 10 min (n = 214) ALS after 10 min (n = 317)
No. of ROSC
No. of Survivals
59 (18%) 32 (16%) 60 (23%) 31 (11%) 52 (24%) 50 (14%) 59 (28%) 43 (12%)
16 (5%) 12 (6%) 22 (9%) 2 (1%) 20 (10%) 5 (1%) 23 (11%) 5 (1%)
* P values were not significant for age comparisons; all others, P < .05.
WUERZ ET AL • AGE AND CARDIAC RESUSCITATION
tigators in Seattle 17 found equal resuscitation outcomes among elderly and younger victims of out-of-hospital cardiac arrest. They also found that, contrary to many fears of persistently vegetative survivors, most patients were discharged. Bonnin et a118 and Safar et a119 reported abstracts with similar results. Our data has several limitations. The numbers of survivors are low, limiting the ability to detect differences between groups. Our EMS system did not use automatic external defibrillation by EMTs, and we have a relatively long ALS response interval because of the rural nature of our service area. It is possible that earlier defibrillation might improve ROSC more than survival, thereby resulting in a difference between age groups as found by Weaver et al. The age groupings we used were arbitrary, and others have used 70 years as a cutoff. However, this was part of our a priori study design, and 65 years is the most widely recognized definition of the elderly age group. Post hoc analysis of our data using the 70-year-old age grouping showed similar results.
REFERENCES 1. Schneider EL, Geraimik JM: The aging of America. JAMA 1990;263:2335-2340 2. Strange GR, Chen EH, Sanders AB: Use of emergency departments by elderly patients: Projections from a multicenter data base. Ann Emerg Med 1992;21:819-824 3. Meador SA: Age-related utilization of advanced life support services. Prehosp Disaster Med 1991 ;6:9-14 4. Murphy DJ: Should emergency physicians make decisions about futility. Med Ethics Phys 1992;7:1-4 5. Baer LS: Cardiopulmonary resuscitation after age 65. Am J Cardiol 1979;43:1065 6. Cummins RO, Chamberlain DA, Abramson NS, et al: Recommended guidelines for uniform reporting of data from outof-hospital cardiac arrest: The Utstein Style. Ann Emerg Med 1991 ;20:861-874
391
7. Eisenberg MS, Horwood BT, Cummins RO, ReynoldsHaertle R, Hearne TR: Cardiac arrest and resuscitation: A tale of 29 cities. Ann Emerg Med 1990;19:179-186 8. Niemann JT: Cardiopulmonary resuscitation. N Engl J Med 327:1075-1080, 1992 9. Weaver WD, Cobb LA, Hallstrom AP, et al: Factors influencing survival after out-of-hospital cardiac arrest. J Am Coil Cardiol 1986;7:752-757 10. Becker LB, Ostrander MP, Barrett J, Kondos GT: Outcome of CPR in a large metropolitan area--Where are the survivors? Ann Emerg Med 1991;20:355-361 11. Lombardi G, Gallagher EJ, Gennis P: Outcome of out-ofhospital cardiac arrest in New York City--The pre-hospital arrest survival evaluation (PHASE) study. JAMA 1994;271:678-683 12. Murphy DJ, Murray AM, Robinson BE, et al: Outcomes of cardiopulmonary resuscitation in the elderly. Ann Intern Med 1989;111:199-205 13. Tresch DD, Thakur RK, Hoffmann RG, et al: Should the elderly be resuscitated following out-of-hospital cardiac arrest? Am J Med 1989;86:145-150 14. Tresch DD, Thakur R, Hoffmann RG, et al: Comparison of outcome of resuscitation of out-of-hospital cardiac arrest in persons younger and older than 70 years of age. Am J Cardio11988; 61:1120-1122 15. Fusgen L, Summa JD: How much sense is there in an attempt to resuscitate an aged person? Gerontology 1978;24: 37-45 16. Van Hoeyweghen RJ, Bossaert LL, Mullie A, et al: Survival after out-of-hospital cardiac arrest in elderly patients. Ann Emerg Med 1992;21:1179-1183 17. Longstreth WT, Cobb LA, Fahrenbruch CE, Copass MK: Does age affect outcomes of out-of-hospital cardiopulmonary resuscitation? JAMA 1990;264:2109-2110 18. Bonnin MJ, Pepe PE, Clark PS: Survival prognosis for the elderly after out-of-hospital cardiac arrest. Ann Emerg Med 1989;14:469 19. Safar P, Abramson N, Detre K: Old age does not negate good outcome after cardiac arrest (CA) and CPR. Resuscitation 1989;17:$133 (suppl)