- Email: [email protected]
Survival after out-of-hospital cardiac arrest in elderly patients
ORIGINAL CONTRIBUTION cardiac arrest CPR do-not-resuscitate orders
Survival After Out-of-Hospital Cardiac Arrest in Elderly Patients From the University of Antwerp, Antwerp, Belgium. Received for publication July 15, 1991. Revision received February 11, 1992. Accepted for publication March 17, 1992.
Raf J Van Hoeyweghen, MD Leo L Bossaert, PhB Arsene Mullie, MD Patrick Martens, MD Herman H Delooz, PhD Walter A Buylaert, PhD Paul A Calle, PhD Luc Corne, MD Belgian Cerebral Resuscitation Study Group
Study objectives: Tostudy whether age of the cardiac arrest patient is related to prognostic factors and survival.
Study design: Retrospective analysis of a prospective registration of cardiac arrest events in the mobile ICUs of seven participating hospitals.
Study population: Two thousand seven hundred seventy-six outof-hospital cardiac arrests in which advanced life support was initiated. Cardiac arrests with a precipitating event requiring specific therapeutic consequences and with specific prognosis were not included in the analysis (eg, trauma, exsanguination, drowning, sudden infant death syndrome). Results: Neither resuscitation rate (23%) nor mortality caused by a neurologic reason (9%) was significantly different between age groups. Mortality after CPR of non-neurologic etiology was significantly higher in the elderly patient (younger than 40 years, 16%; 40 to 69 years, 19%; 70 to 79 years, 30%; 80 years or older, 34%; P< .005)and had a negative effect on survival in resuscitated elderly patients (P< .05). Elderly patients more frequently had a dependent lifestyle before the arrest (P< .025), an arrest of cardiac origin (P< .001), electromechanical dissociation as the type of cardiac arrest (P< .025), and a shorter duration of advanced life support in unsuccessful resuscitation attempts (r= -.178, P< .0001). Conclusion: Because survival two weeks after CPR was not significantly different between age groups, we suggest that decision making in CPR should not be based on age but on factors with better predictive power for outcome and quality of survival. [Van Hoeyweghen RJ, Bossaert LL, Mullie A, Martens P, Delooz HH, Buylaert WA, Calle PA, Come L, Belgian Cerebral Resuscitation Study Group: Survival after out-of-hospital cardiac arrest in elderly patients. Ann EmergMed October 1992;21:1179-1184.]
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INTRODUCTION CPR is a standard intervention inside and outside the hospital to restore failing circulation and respiration. Prompt initiation of CPR is recommended in witnessed cardiac arrest of u n k n o w n patients. The decision to continue or to withdraw advanced life support is based on clinical parameters and/or ethical considerations. Patients with a poor chance for successful outcome and a poor chance for an acceptable quality of life or patients suffering from a terminal ilh~ess might he resuscitated, and the process of dying and suffering might he prohmged.t In these cases, a statement of the patient's wish not to be resuscitated is required to prevent traumatic, futile, and expensive resuscitation attempts. Advanced age is an oft-cited argument to withhold CPR from a patient. Some authors suggest that, in the in-hospital setting, patients older than 65 or 70 years shmdd only be resuscitated in selected cases. 2,3 Outside the hosl)ital, CPR for the elderly has been described as rarely effective;¢ although, relevant literature suggests that age is not a negative predictor of outcome, z- t i Medicine is facing an increase in the prevalence of patients in their 70s and 80s. Because the prevalence of cardiac arrest is higher in these patients, 12 the dilemma of withhohling or withdrawing CPR in elderly patients will become even more acute than it is now. Most studies on the influence of age on survival after cardiac arrest have involved limited numhers of patients 3-(~-l° and lacked clarity and precision in reporting (eg, patient selection criteria, stratification for underlying disease).2, 5 The aim of this report is to determine whether advanced age couht he used in decision making before or during CPR by studying the influence of age nn prognostic factors of survival after cardiac arrest and to determine survival rate in age groups stratified for prearrest conditions. MATERIALS AND METHODS Seven emergency medical service (EMS) systems using a central telephone dispatch (dial 100) and a mobile ICU (MICU) team, participated and registered prospectively all cardiac arrest events during a five-year period (1983 to 1987). EMS systems were two tiered: The first tier consisted of a primary ambulance with basic life support (BLS) facilities; the second tier consisted of a rescue ambulance with an experienced emergency physician amt/or nurse, Outcome results between different centers were not significantly different. L~ The MICU team could he alerted by bystanders (using the 100 telephone dispatch system) or medieal professionals, i n nursing homes, do-not-resuscitate instructions were respected if ordered, and in these cases the EMS system was not activated. The registration form was completed by an MICU nurse or physician as soon as possible after the resuscitation procedure. The registration form and general results are described in detail in a previous report of the study group.14
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Only cardiac arrests confirmed by ECG monitoring where advanced life support (ALS) was initiated were included in the registration. Because only cardiac arrest cases where ALS was initiated were included in the registry, it is not known how many cardiac arrests have occurred where ALS was not initiated. A cardiac arrest occurring during transport by the MICU team to the hospital was considered an inhospital event hecause ALS and a medical team were available in the vehicle. In these circumstances, response times are virtually zero, as in the in-hospital situation. Patients suffering a cardiac arrest with underlying disease trauma, exsanguination, anesthesia, drowning, or sudden infant death syndrome were not included in this analysis. Arrests were considered to be witnessed when seen or heard by bystanders (last three years of registration) or when the access time of the event in the EMS system was less than one minute (first two years of registration). Retrospectively, witnessing of the arrest was significantly related to an access time of one minute or less. 14 Prearrest health state was recorded according to the classification of Jennet and Bond. is Access interval was defined as the interval between collapse and the moment the EMS system was alerted. This interval was estimated by bystanders. 16 Response interval of BLS was defined as the interval between collapse and initiation of basic CPR either by bystanders, ambulance personnel, or the MICU team. Response interval of ALS was defined as the interval between the collapse and the initiation of ALS by the MICU team. Response interval of BLS was estimated by bystanders or ambulance personnel. Response interval of ALS and duration of ALS were estimated by the MICU team. The telephone dispatch system recorded accurately when the EMS system was alerted, when the MICU team left the hospital, and when it arrived at the scene of the arrest. The type of cardiac arrest on arrival of the MICU was classified as ventricular fibrillation (including ventricular tachycardia causing collapse), asystole, or electromechanical dissociation. A CPR attempt was considered a failure if the patient died before admission to the hospital. A CPR attempt was Table 1. Effect of age on outcome after cardiac arrest
Age Groups(yr) <40 40-69 70-79 (N =220) (N = 1,382) (N =826) No.(%) No,(%) No.(%) Admitted ND* NND Long-term survival
>80 To~l (N =327) (N =2,755) No.(%) No.(%)
50 (23) 27(12) 8 (4)
318 (23) 127 (9) 60 (4)
196 (24) 77 (9) 59 (7)
61 {19) 21 (6) 21 (6)
625(23) 252 (9) 148 (5)
NS NS <.001
15 (7)
131 (9)
60 (7)
19 (6)
225 (8)
NS
*ND, neurologi¢ deaths within 14 days afer CPR. *NND, non-neurologic deaths within 14 days after (~PR. Missing data (N=2;}. Z2 test was used to evaluate differences between age groups.
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considered as initially successful if the patient was admitted to the hospital. Long-term survival was defined as consciousness at 14 days after the cardiac arrest event. If the patient died within 14 days after CPR, the p r i m a r y cause of death was recorded as neurologic or non-neurologic. Patients in a vegetative state at day 14 were classified as neurologically dead. Values are reported as mean + standard deviation. Qualitative data have been analyzed by the Z2 test, quantitative data by the Student's t-test. The correlation between age and time was analyzed by the Pearson correlation coefficient. Significance was assumed at the .05 level of probability. RESULTS
The 2,776 studied out-of-hospital cardiac arrests were admitted to the hospital in 23% of cases (Table 1). Long-term survival rate was 8%, with no significant differences between age groups. The n u m b e r of patients who died within 14 days after CPR because of non-neurologic reasons was significantly higher in the older age groups (P < .001). This was also the case when only admitted patients were considered (P < .005). In contrast, mortality caused by a neurologic death after resuscitation was not significantly different between age groups. Highest long-term survival rate was observed in the age group 40 to 69 years. This was significantly different from the other age groups considering only admitted patients (younger than 40 years, 30%; 40 to 69 years, 41%; 70 to 79 years, 31%; 80 years or older, 31%; P < .05). The most freTable 2. Prevalence of different location, underlying disease, witnessing, and prearrest health state in different age groups o f cardiac arrest (N=2,776)
<40
Age Groups (yr) (%) 40-69 70-79 __>80
Total N %
P
Location At home PuNic place Atwork Transportation Missing data
69 22 5 4
70 21 4 5
70 24 0.1 6
76 1,941 70 16 593 22 0.3 70 3 7 151 5 21 1
NS <.05 <.05 NS
39 24 7 14 17
87 6 2 2 4
92 4 2 0.6 2
94 2,351 85 2 175 6 0.3 53 2 0.3 64 2 3 112 4 21 1
<.001 <.001 <.001 <.001 <.001
Underlying disease Acute cardiac Respiratory Intracranial Intoxication Others Missing data
Witnessed or not Witnessed Not witnessed Missing data
45 55
57 43
57 43
59 41
1,458 53 1,142 41 178 6
71 20 8 1
56 37 6 0.3
46 45 8 0.2
38 51 11 0
1,436 52 <.001 1,100 40 <.001 207 7 <.go5 8 0.3 - 25 1
<.05
Prearrest health status Functionally normal Disabled/independent Disabled/dependent Unconscious Missing data
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quent location of the arrest (Table 2) was the home of the patient (70%). Elderly patients, aged 80 years or older, collapsed more frequently at home (76%, NS) than the other age groups less frequently at a public place (all ages, 22%; 80 years or older, 16%; P < .05). The disease underlying the cardiac arrest was presumed to be of cardiac origin in 85% of cases. The collapse was witnessed in 53% of the patients, and in 52% it concerned a fully functional individual. Patients older than 70 years were significantly more disabled and more often had a dependent lifestyle before the arrest. The prevalence of ventricular fibrillation was significantly lower in the age groups younger than 40 years and 80 years and older than in the age groups 40 to 69 years (30%) and 70 to 79 years (32%) (P < .001). The prevalence of asystole was significantly different between age groups (younger than 40 years, 75%; 40 to 69 years, 61%; 70 to 79 years, 56%; 80 years or older, 67%) (P < .001). Electromechanical dissociation occurred more frequently in patients older than 70 years (12% versus 9%, P < .025). Patients in ventricular fibrillation who were 80 years old or older were admitted to the hospital significantly less often than other age groups (32% versus 41%, P < .001). No significant difference could be observed in admission rates of patients in asystole or electromechanical dissociation (16% and 15%, respectively). Within the three subgroups of cardiac arrest, no significant differences in long-term survival were observed among age groups (ventricular fibrillation, 18%; asystole, 4%; electromechanical dissociation, 3%). Tables 3 and 4 summarize the relation between prearrest health state in different age groups and the outcome according to prearrest health state. Within each subgroup of prearrest health state, neither short-term or long-term survival was influenced by age. In this study of cardiac arrest, the EMS system was alerted after 4.3 + 9.8 minutes. The response intervals were 8.8 + 13.6 minutes for BLS and 18.5 + 11.2 minutes for ALS. Pearson's correlation coefficient demonstrated that access interval (r = -.097, P < .0001), BLS response interval (r = -.093, P < .0001), and ALS response interval (r = - . 170, P < .0001) became significantly shorter as the patient's age increased.
Table 3. Prevalence of type of prearrest health state (PAHS) according to the age of the patient Age Groups (yr) < 40 40-69 70-79 (N = 220) (N =1,381) (N=823) N (%) N (%) N (%)
> 80 Total (N=327) (N=2,751) N (%) N (%)
P
PAHS 1" 200 (91) 1,292 (94) 753 (91) 291 (89) 2,536 (92) < .025 PANS2 18 (8) 85 (6) 68 {8) 36(11) 207 (8) <.025 PAHS3 2 (1) 4 (0.3) 2 (0.3) 0 (0) 8 (0.3) *PAHS 1, functionally normal or disabled but independent; PAHS 2, disabled and dependent.; PAHS 3, coma. Missing data (N=25).
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Duration of ALS in unsuccessful CPR attempts was shorter in patients with dependent p r e a r r e s t lifestyle (23.9 + 14.7 minutes; P < .01) than in patients with independent prearrest lifestyle (31.3 + 22.9 minutes; P < .01). I n both groups of patients, ALS duration was significantly shorter in elderly patients (independent: r = - . 1 7 8 , P < .0001; dependent: r = - . 2 0 2 , P < .004). DISCUSSION
During a five-year period, a data base of cardiac arrest patients receiving ALS was compiled prospectively; however, only cardiac arrests without an overt underlying disease were included in the analysis. Frequently, the patient's wishes concerning resuscitation were not known at the time of intervention. Therefore, patients without evident underlying disease were regarded as the subgroup with the most clinical relevance. A n u m b e r of cases were missing data, and time intervals were estimated by bystanders (eg, access time). Long-term survival was determined at 14 days after CPR, which might be comparable with discharge from hospital b u t not with long-term survival as defined by others. 16,17 Our results do not demonstrate a negative effect of advanced age on immediate success of resuscitation. This is a general finding in the hterature. 18d9 Short-term neurologic consequences of ischemia/anoxia related to circulatory arrest seem to have an equal impact on the young and old. Indeed, the prevalence of neurologic deaths within 14 days after CPR was not significantly different between age groups. This has previously been noted by Tresch et al. u Although the acute event is neurologically equally tolerated, the reconvalescence period in the elderly is characterized by a higher non-neurologic mortality (eg, cardiac failure, sepsis), which may be the Table 4. Outcome of cardiac arrest according to type of prenrrest health state (PAHS) in different age groups Age Groups(yr) < 40 40-69 70-79 (N=220) (N=1,381) (N=823) N (%) N (%) N (%)
k 8Q Total (N=327) (N=2,751) N (%) N (%)
2,536 PAHS 1 200 1,292 753 291 Admitted 45 (23) 301 (23) 182 (24) 56 (19) 584 (23) Long-term 214 (8) survival 13 (7) 125(10) 58 (8) 18 (6} 207 PAHS 2 18 85 68 36 38(18) Admitted 4 (22) 17 (20) 12 (18) 5 (14) Long-term 11 (5) survival 2(11) 6 (7) 2 (3) 1 (3) PAHS 3 2 4 2 0 8 3 (38) Admitted 1 (50) O {0) 2 (100) Long -term survival 0 (0) 0 (0) *PAHS 1, functionally normal or disabled but independent. PAHS 2, disabled and dependent. PAHS 3, coma. Missing data (N=25),
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NS NS NS NS
result of decreased physiologic reserve in the geriatric patient. The prevalence of p e r m a n e n t neurologic sequelae after resuscitation was not investigated in this study nor did we investigate the number of survivors beyond two weeks. In hospitalized9d ° as well as out-of-hospital cardiac arrest patients ,11 elderly survivors are not r e p o r t e d to suffer from more residual neurologic impairment. Long-term survival of elderly survivors of cardiac arrest is controversial. Tresch et al u and Myerburg et al 2° failed to demonstrate that the patient's age was a p r e d i c t o r of long-term survival n,20 whereas Eisenberg et aP 6 and Baum et aP 7 demonstrated the reverse. Multivariate analysis on patients included in the Brain Resuscitation Clinical Trial 1 showed age as an independent p r e d i c t o r of death b u t not of recovery with b r a i n damage .21 However, in Brain Resuscitation Clinical Trial 2, age was an independent predictor of neither mortality nor survival with b r a i n damage. 21 Another question is whether the higher prevalence of non-neurologic deaths in the elderly population is solely the result of a higher vulnerability caused by senescence or whether there is an influence of p r e - C P R conditions. Mullie et aD 3 discussed that p r e - C P R conditions (underlying disease, p r e a r r e s t health status, location, type of cardiac arrest) significantly influence survival. In our study, the patients younger than 40 years shared characteristics significantly different from older age groups. Clinton et a122 r e p o r t e d that cardiac arrest victims younger the age of 40 years less frequently suffer a cardiac arrest of cardiac origin. Our data also suggest that these patients are more frequently fully functional before to the arrest and that arrests in patients aged younger than 40 years more often take place at public places. Elderly patients are more frequently struck by an arrest of cardiac origin at home, where their survival was significantly lower, and were frequently in a p o o r e r prearrest health state.iS In the out-of-hospital setting, it has been demonstrated that the p r e a r r e s t health state does not have an influence on survival. 13 The fact that p r e a r r e s t health state did not influence long-term survival in our study confirms the observation of other authors that (in-hospital) patients suffering a b a d general condition still have a considerable chance for survival and that this chance for survival is not influenced by age. a The prevalence of patients in ventricular fibrillation on a r r i v a l of the MICU team is low compared with other reports. 23 This can p r o b a b l y be explained by the relatively long response intervals of the Belgian EMS system. In a previous study, Bossaert et a124 observed that elderly cardiac arrest patients were less frequently resuscitated by bystanders and that b y s t a n d e r CPR might have a beneficial effect by maintaining more patients in ventricular fibrillation. 24 In p a r t , this might explain the observation that in elderly cardiac arrest patients, electromechanical dissociation and asystole was observed more frequently at arrival of the
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MICU. This difference in rhythms also was observed by other investigators. 25,26 Besides pre-CPR conditions, it is evident that response intervals have a significant effect on survival, z7 The Belgian EMS system has, compared with some other studies, r a t h e r long response times. 23 This is p r o b a b l y due to organizational differences in the EMS system, such as the density of MICU teams and the widespread use of a two-tiered system, ancient city centers with narrow streets, and a delayed notification of the EMS system by bystanders. Access and response intervals of BLS and ALS were significantly shorter in elderly patients, which might bias outcome results in different age groups. This age-related difference in out-of-hospital EMS response might be explaine~l because the registry included only cardiac arrests that received ALS. Indeed, no information is available on patients in whom ALS was not initiated. It is possible that there was less willingness to initiate ALS in elderly patients compared with younger subjects. A different attitude toward elderly patients and patients with a dependent lifestyle is evident from our analysis of the duration of ALS in unsuccessful CPR attempts. The d u r a tion of the CPR attempt has been considered by Nightingale and Grant 2s as a measure of actual practices during the attempt because guidelines on when to declare resuscitation efforts unsuccessful leave considerable room for individual discretion. It remains unclear whether the decision to cease CPR earlier in elderly and dependent patients was based on clinical findings or on p r o v i d e r decisions, to spare further suffering. CONCLUSION
Finally, we conclude that the chronologic age of a patient should not be used as the only determinant in the decision to withhold or to withdraw CPR. In cases without advance directives, the decision not to resuscitate should be based on a set of conditions that accurately predicts outcome and quality of survival. If known, the patient's wishes, the extent of the patient's disease(s), and the level of physical and mental function can be the most i m p o r t a n t determinants in decision making.5,n Unfortunately this information is not always available outside the hospital. In the hospital, however, a clear "DNR" policy that considers all admitted patients probably is the best prevention of unnecessary suffering by inappropriate CPR.
REFERENCES 1. Blakhall LJ: Must we always use CPR? NEoglJMed1987;317:1281,1284. 2. Taffet 6E, Teasdale TA, Luchi RJ: In-hospital cardiopulmonary resuscitation. JAMA 19881260:2069-2072. 3. Bear LS: Cardiopulmonary resuscitation after age fi5. Am J Cardio1197914311065. 4. Murphy DJ, Murray AM, Robinson BE, et al: Outcomes of cardiopulmonary resuscitation in the elderly. Ann Intern Med 19891111:199-205. 5. F[Jsgen I, Summa J-D: How much sense is there in an attempt to resuscitate an aged person? Gerontology1978;24:37-45. 6. Bayer A J, Ang BC, Pathy MSJ: Cardiac arrest in a geriatric unit. AgeAging 1985:14:271-276. 7. Gordon M, Hurowitz E: Cardiopulmonary resuscitation of the elderly. JAm GeriatrSoc 1984132:930-935. 8. Horsey CO, Fisher L: Why outcome of cardiopulmonary resuscitation in general wards is poor, Lancet 1982;1:31-34. 9. Bedell SE, Delbanco TL, Cook F, et ah Survival after cardiopulmonary resuscitation in the hospital. N Engl J Med 19831309:569-576. 10. Gulati RJ, Bhan GL, Horan MA: Cardiopulmonary resuscitation of old people. Lancet 198312:267-269. 11. Tresch DO, Thakur RK, Hoffmann RG, et al: Should the elderly be resuscitated following out-of-hospital cardiac arrest? Am J Met 1989;86:145-150. 12. Kannel WB, Thomas HE: Sudden coronary death: The Framingham study. Ann NY Acad Sol 1982;382:3-21. 13. Mullie A, Lewi P, Van Hoeyweghen R, et al: Pre-CPR conditions and the final outcome of CPR. Resuscitation 1989;17(suppl 1):11-21. 14. The Cerebral Resuscitation Study Group: The Belgian CPCR registry: Form protocol. Resuscitation 198911 (suppl):5-10. 15. Jennet B, Bond M: Assessment of outcome after severe brain damage: A practical scale. Lancet 197511:480-484. 16. Eisenberg MS, Hallstrem A, Bergner L: Long-term survival after out-of-hospital cardiac arrest. NEnglJMed19821306:1340-1343. 17. Baum RS, Alvarez H, Cobb LA: Survival after resuscitation from out-of-hospital ventricular fibrillation. Circulation 1974150:1231-1235. 18. Eisenberg M, Bergner L, Hallstrom A: Paramedic programs and out-of-hospital cardiac arrest t. Factors related with successful resuscitation. Am J Public Health 1979;69:30-38. 19. Weaver WD, Cobb LA, Hallstrom AP, et ah Factors influencing survival after out-ofhospital cardiac arrest. JAm Coil Cardio1198617:752-757. 20. Myerburg RJ, Condo CA, Sung RJ, et al: Clinical, electrophysiolegic and hemodynamic profile of patients resuscitated from prehospita] cardiac arrest. Am J Med 1980;68:568-576. 21. Safar P, Abramson N, Detre K, et al: Old age does not negate good outcome after cardiac arrest and CPR (abstract). CritCareMef11989;17:S13& 22. Clinton JE, Mc6ill J, Irwin G, et al: Cardiac arrest under age 40: Etiology and prognosis. Ann Emerg Med 1984113:1011-1015. 23. Weaver WD, Hill DH, Fahrenbruch CE, et al: Use of the automatic external defibrillator in the management of out-of-hospital cardiac arrest. N EnglJ Med 1988;319:661-666. 24. Bossaert L, Van Hoeyweghen R, Cerebral Resuscitation Study Group: Bystander CPR in out-of-hospital cardiac arrest. Resuscitation 1989117(suppl):S55-S69. 25. Tresch DO, Thakur RK, Hoffman R6, et al: Comparison of outcome of out-of-hospital cardiac arrest in persons younger and older than 70 years of age. Am J Cardiol 1988;61:1120-1122. 26. Suton-Tyrell K, Abramson NS, Safar P, et al: Predictors of electromechanical dissociation during cardiac arrest. Ann Emerg Med 1988;17:572-575. 27. Mullie A, Van Hoeyweghen R, Ouets A, et al: Influence of time intervals on outcome of CPR. Resuscitation 1989;17(suppl 1):23-33. 28. Nightingale SD, Grant M: Risk preference and decision making in critical care situations. Chest1988193:684-687.
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The Belgian Cerebral Resuscitation Study Group A Mullie P Martens PVerstringe Department of Critical Care Medicine Algameen Ziekenhuis Sint Jan Brugge
Address for reprints: Leo Bossaert, MD University of Antwerp-UlA Universiteitsplein 1 B 2610 Antwerp, Belgium
W Buylaert P Calle H Houbrechts Department of Emergency Medicine Universitair Ziekenhuis Gent L Come D Lauwaert Department of EmergencyMedicine Akademisch ZiekenhuisVrije Universiteit Brussels H Delooz H Verbruggen Department of EmergencyMedicine Universitair Ziekenhuis St RafaeI-Gasthuisberg Leuven R De Cock M Weeghmans Department of Emergency Medicine Imeldaziekenhuis, Bonheide J Mennes Department of EmergencyMedicine Jan Palfijn Ziekenhuis Merksem L Bossaert R Van Hoeyweghen Department of Intensive Care UIA Universitair Ziekenhuis Antwerp P Lewi A Quets Department of Information Sciences Janssen Research Foundation Beerse
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Survival After Out-of-Hospital Cardiac Arrest in Elderly Patients From the University of Antwerp, Antwerp, Belgium. Received for publication July 15, 1991. Revision received February 11, 1992. Accepted for publication March 17, 1992.
Raf J Van Hoeyweghen, MD Leo L Bossaert, PhB Arsene Mullie, MD Patrick Martens, MD Herman H Delooz, PhD Walter A Buylaert, PhD Paul A Calle, PhD Luc Corne, MD Belgian Cerebral Resuscitation Study Group
Study objectives: Tostudy whether age of the cardiac arrest patient is related to prognostic factors and survival.
Study design: Retrospective analysis of a prospective registration of cardiac arrest events in the mobile ICUs of seven participating hospitals.
Study population: Two thousand seven hundred seventy-six outof-hospital cardiac arrests in which advanced life support was initiated. Cardiac arrests with a precipitating event requiring specific therapeutic consequences and with specific prognosis were not included in the analysis (eg, trauma, exsanguination, drowning, sudden infant death syndrome). Results: Neither resuscitation rate (23%) nor mortality caused by a neurologic reason (9%) was significantly different between age groups. Mortality after CPR of non-neurologic etiology was significantly higher in the elderly patient (younger than 40 years, 16%; 40 to 69 years, 19%; 70 to 79 years, 30%; 80 years or older, 34%; P< .005)and had a negative effect on survival in resuscitated elderly patients (P< .05). Elderly patients more frequently had a dependent lifestyle before the arrest (P< .025), an arrest of cardiac origin (P< .001), electromechanical dissociation as the type of cardiac arrest (P< .025), and a shorter duration of advanced life support in unsuccessful resuscitation attempts (r= -.178, P< .0001). Conclusion: Because survival two weeks after CPR was not significantly different between age groups, we suggest that decision making in CPR should not be based on age but on factors with better predictive power for outcome and quality of survival. [Van Hoeyweghen RJ, Bossaert LL, Mullie A, Martens P, Delooz HH, Buylaert WA, Calle PA, Come L, Belgian Cerebral Resuscitation Study Group: Survival after out-of-hospital cardiac arrest in elderly patients. Ann EmergMed October 1992;21:1179-1184.]
OCTOBER1992
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CARDIAC ARREST Van ltoeyweghon et a/
n
i
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INTRODUCTION CPR is a standard intervention inside and outside the hospital to restore failing circulation and respiration. Prompt initiation of CPR is recommended in witnessed cardiac arrest of u n k n o w n patients. The decision to continue or to withdraw advanced life support is based on clinical parameters and/or ethical considerations. Patients with a poor chance for successful outcome and a poor chance for an acceptable quality of life or patients suffering from a terminal ilh~ess might he resuscitated, and the process of dying and suffering might he prohmged.t In these cases, a statement of the patient's wish not to be resuscitated is required to prevent traumatic, futile, and expensive resuscitation attempts. Advanced age is an oft-cited argument to withhold CPR from a patient. Some authors suggest that, in the in-hospital setting, patients older than 65 or 70 years shmdd only be resuscitated in selected cases. 2,3 Outside the hosl)ital, CPR for the elderly has been described as rarely effective;¢ although, relevant literature suggests that age is not a negative predictor of outcome, z- t i Medicine is facing an increase in the prevalence of patients in their 70s and 80s. Because the prevalence of cardiac arrest is higher in these patients, 12 the dilemma of withhohling or withdrawing CPR in elderly patients will become even more acute than it is now. Most studies on the influence of age on survival after cardiac arrest have involved limited numhers of patients 3-(~-l° and lacked clarity and precision in reporting (eg, patient selection criteria, stratification for underlying disease).2, 5 The aim of this report is to determine whether advanced age couht he used in decision making before or during CPR by studying the influence of age nn prognostic factors of survival after cardiac arrest and to determine survival rate in age groups stratified for prearrest conditions. MATERIALS AND METHODS Seven emergency medical service (EMS) systems using a central telephone dispatch (dial 100) and a mobile ICU (MICU) team, participated and registered prospectively all cardiac arrest events during a five-year period (1983 to 1987). EMS systems were two tiered: The first tier consisted of a primary ambulance with basic life support (BLS) facilities; the second tier consisted of a rescue ambulance with an experienced emergency physician amt/or nurse, Outcome results between different centers were not significantly different. L~ The MICU team could he alerted by bystanders (using the 100 telephone dispatch system) or medieal professionals, i n nursing homes, do-not-resuscitate instructions were respected if ordered, and in these cases the EMS system was not activated. The registration form was completed by an MICU nurse or physician as soon as possible after the resuscitation procedure. The registration form and general results are described in detail in a previous report of the study group.14
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Only cardiac arrests confirmed by ECG monitoring where advanced life support (ALS) was initiated were included in the registration. Because only cardiac arrest cases where ALS was initiated were included in the registry, it is not known how many cardiac arrests have occurred where ALS was not initiated. A cardiac arrest occurring during transport by the MICU team to the hospital was considered an inhospital event hecause ALS and a medical team were available in the vehicle. In these circumstances, response times are virtually zero, as in the in-hospital situation. Patients suffering a cardiac arrest with underlying disease trauma, exsanguination, anesthesia, drowning, or sudden infant death syndrome were not included in this analysis. Arrests were considered to be witnessed when seen or heard by bystanders (last three years of registration) or when the access time of the event in the EMS system was less than one minute (first two years of registration). Retrospectively, witnessing of the arrest was significantly related to an access time of one minute or less. 14 Prearrest health state was recorded according to the classification of Jennet and Bond. is Access interval was defined as the interval between collapse and the moment the EMS system was alerted. This interval was estimated by bystanders. 16 Response interval of BLS was defined as the interval between collapse and initiation of basic CPR either by bystanders, ambulance personnel, or the MICU team. Response interval of ALS was defined as the interval between the collapse and the initiation of ALS by the MICU team. Response interval of BLS was estimated by bystanders or ambulance personnel. Response interval of ALS and duration of ALS were estimated by the MICU team. The telephone dispatch system recorded accurately when the EMS system was alerted, when the MICU team left the hospital, and when it arrived at the scene of the arrest. The type of cardiac arrest on arrival of the MICU was classified as ventricular fibrillation (including ventricular tachycardia causing collapse), asystole, or electromechanical dissociation. A CPR attempt was considered a failure if the patient died before admission to the hospital. A CPR attempt was Table 1. Effect of age on outcome after cardiac arrest
Age Groups(yr) <40 40-69 70-79 (N =220) (N = 1,382) (N =826) No.(%) No,(%) No.(%) Admitted ND* NND Long-term survival
>80 To~l (N =327) (N =2,755) No.(%) No.(%)
50 (23) 27(12) 8 (4)
318 (23) 127 (9) 60 (4)
196 (24) 77 (9) 59 (7)
61 {19) 21 (6) 21 (6)
625(23) 252 (9) 148 (5)
NS NS <.001
15 (7)
131 (9)
60 (7)
19 (6)
225 (8)
NS
*ND, neurologi¢ deaths within 14 days afer CPR. *NND, non-neurologic deaths within 14 days after (~PR. Missing data (N=2;}. Z2 test was used to evaluate differences between age groups.
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considered as initially successful if the patient was admitted to the hospital. Long-term survival was defined as consciousness at 14 days after the cardiac arrest event. If the patient died within 14 days after CPR, the p r i m a r y cause of death was recorded as neurologic or non-neurologic. Patients in a vegetative state at day 14 were classified as neurologically dead. Values are reported as mean + standard deviation. Qualitative data have been analyzed by the Z2 test, quantitative data by the Student's t-test. The correlation between age and time was analyzed by the Pearson correlation coefficient. Significance was assumed at the .05 level of probability. RESULTS
The 2,776 studied out-of-hospital cardiac arrests were admitted to the hospital in 23% of cases (Table 1). Long-term survival rate was 8%, with no significant differences between age groups. The n u m b e r of patients who died within 14 days after CPR because of non-neurologic reasons was significantly higher in the older age groups (P < .001). This was also the case when only admitted patients were considered (P < .005). In contrast, mortality caused by a neurologic death after resuscitation was not significantly different between age groups. Highest long-term survival rate was observed in the age group 40 to 69 years. This was significantly different from the other age groups considering only admitted patients (younger than 40 years, 30%; 40 to 69 years, 41%; 70 to 79 years, 31%; 80 years or older, 31%; P < .05). The most freTable 2. Prevalence of different location, underlying disease, witnessing, and prearrest health state in different age groups o f cardiac arrest (N=2,776)
<40
Age Groups (yr) (%) 40-69 70-79 __>80
Total N %
P
Location At home PuNic place Atwork Transportation Missing data
69 22 5 4
70 21 4 5
70 24 0.1 6
76 1,941 70 16 593 22 0.3 70 3 7 151 5 21 1
NS <.05 <.05 NS
39 24 7 14 17
87 6 2 2 4
92 4 2 0.6 2
94 2,351 85 2 175 6 0.3 53 2 0.3 64 2 3 112 4 21 1
<.001 <.001 <.001 <.001 <.001
Underlying disease Acute cardiac Respiratory Intracranial Intoxication Others Missing data
Witnessed or not Witnessed Not witnessed Missing data
45 55
57 43
57 43
59 41
1,458 53 1,142 41 178 6
71 20 8 1
56 37 6 0.3
46 45 8 0.2
38 51 11 0
1,436 52 <.001 1,100 40 <.001 207 7 <.go5 8 0.3 - 25 1
<.05
Prearrest health status Functionally normal Disabled/independent Disabled/dependent Unconscious Missing data
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quent location of the arrest (Table 2) was the home of the patient (70%). Elderly patients, aged 80 years or older, collapsed more frequently at home (76%, NS) than the other age groups less frequently at a public place (all ages, 22%; 80 years or older, 16%; P < .05). The disease underlying the cardiac arrest was presumed to be of cardiac origin in 85% of cases. The collapse was witnessed in 53% of the patients, and in 52% it concerned a fully functional individual. Patients older than 70 years were significantly more disabled and more often had a dependent lifestyle before the arrest. The prevalence of ventricular fibrillation was significantly lower in the age groups younger than 40 years and 80 years and older than in the age groups 40 to 69 years (30%) and 70 to 79 years (32%) (P < .001). The prevalence of asystole was significantly different between age groups (younger than 40 years, 75%; 40 to 69 years, 61%; 70 to 79 years, 56%; 80 years or older, 67%) (P < .001). Electromechanical dissociation occurred more frequently in patients older than 70 years (12% versus 9%, P < .025). Patients in ventricular fibrillation who were 80 years old or older were admitted to the hospital significantly less often than other age groups (32% versus 41%, P < .001). No significant difference could be observed in admission rates of patients in asystole or electromechanical dissociation (16% and 15%, respectively). Within the three subgroups of cardiac arrest, no significant differences in long-term survival were observed among age groups (ventricular fibrillation, 18%; asystole, 4%; electromechanical dissociation, 3%). Tables 3 and 4 summarize the relation between prearrest health state in different age groups and the outcome according to prearrest health state. Within each subgroup of prearrest health state, neither short-term or long-term survival was influenced by age. In this study of cardiac arrest, the EMS system was alerted after 4.3 + 9.8 minutes. The response intervals were 8.8 + 13.6 minutes for BLS and 18.5 + 11.2 minutes for ALS. Pearson's correlation coefficient demonstrated that access interval (r = -.097, P < .0001), BLS response interval (r = -.093, P < .0001), and ALS response interval (r = - . 170, P < .0001) became significantly shorter as the patient's age increased.
Table 3. Prevalence of type of prearrest health state (PAHS) according to the age of the patient Age Groups (yr) < 40 40-69 70-79 (N = 220) (N =1,381) (N=823) N (%) N (%) N (%)
> 80 Total (N=327) (N=2,751) N (%) N (%)
P
PAHS 1" 200 (91) 1,292 (94) 753 (91) 291 (89) 2,536 (92) < .025 PANS2 18 (8) 85 (6) 68 {8) 36(11) 207 (8) <.025 PAHS3 2 (1) 4 (0.3) 2 (0.3) 0 (0) 8 (0.3) *PAHS 1, functionally normal or disabled but independent; PAHS 2, disabled and dependent.; PAHS 3, coma. Missing data (N=25).
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Duration of ALS in unsuccessful CPR attempts was shorter in patients with dependent p r e a r r e s t lifestyle (23.9 + 14.7 minutes; P < .01) than in patients with independent prearrest lifestyle (31.3 + 22.9 minutes; P < .01). I n both groups of patients, ALS duration was significantly shorter in elderly patients (independent: r = - . 1 7 8 , P < .0001; dependent: r = - . 2 0 2 , P < .004). DISCUSSION
During a five-year period, a data base of cardiac arrest patients receiving ALS was compiled prospectively; however, only cardiac arrests without an overt underlying disease were included in the analysis. Frequently, the patient's wishes concerning resuscitation were not known at the time of intervention. Therefore, patients without evident underlying disease were regarded as the subgroup with the most clinical relevance. A n u m b e r of cases were missing data, and time intervals were estimated by bystanders (eg, access time). Long-term survival was determined at 14 days after CPR, which might be comparable with discharge from hospital b u t not with long-term survival as defined by others. 16,17 Our results do not demonstrate a negative effect of advanced age on immediate success of resuscitation. This is a general finding in the hterature. 18d9 Short-term neurologic consequences of ischemia/anoxia related to circulatory arrest seem to have an equal impact on the young and old. Indeed, the prevalence of neurologic deaths within 14 days after CPR was not significantly different between age groups. This has previously been noted by Tresch et al. u Although the acute event is neurologically equally tolerated, the reconvalescence period in the elderly is characterized by a higher non-neurologic mortality (eg, cardiac failure, sepsis), which may be the Table 4. Outcome of cardiac arrest according to type of prenrrest health state (PAHS) in different age groups Age Groups(yr) < 40 40-69 70-79 (N=220) (N=1,381) (N=823) N (%) N (%) N (%)
k 8Q Total (N=327) (N=2,751) N (%) N (%)
2,536 PAHS 1 200 1,292 753 291 Admitted 45 (23) 301 (23) 182 (24) 56 (19) 584 (23) Long-term 214 (8) survival 13 (7) 125(10) 58 (8) 18 (6} 207 PAHS 2 18 85 68 36 38(18) Admitted 4 (22) 17 (20) 12 (18) 5 (14) Long-term 11 (5) survival 2(11) 6 (7) 2 (3) 1 (3) PAHS 3 2 4 2 0 8 3 (38) Admitted 1 (50) O {0) 2 (100) Long -term survival 0 (0) 0 (0) *PAHS 1, functionally normal or disabled but independent. PAHS 2, disabled and dependent. PAHS 3, coma. Missing data (N=25),
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NS NS NS NS
result of decreased physiologic reserve in the geriatric patient. The prevalence of p e r m a n e n t neurologic sequelae after resuscitation was not investigated in this study nor did we investigate the number of survivors beyond two weeks. In hospitalized9d ° as well as out-of-hospital cardiac arrest patients ,11 elderly survivors are not r e p o r t e d to suffer from more residual neurologic impairment. Long-term survival of elderly survivors of cardiac arrest is controversial. Tresch et al u and Myerburg et al 2° failed to demonstrate that the patient's age was a p r e d i c t o r of long-term survival n,20 whereas Eisenberg et aP 6 and Baum et aP 7 demonstrated the reverse. Multivariate analysis on patients included in the Brain Resuscitation Clinical Trial 1 showed age as an independent p r e d i c t o r of death b u t not of recovery with b r a i n damage .21 However, in Brain Resuscitation Clinical Trial 2, age was an independent predictor of neither mortality nor survival with b r a i n damage. 21 Another question is whether the higher prevalence of non-neurologic deaths in the elderly population is solely the result of a higher vulnerability caused by senescence or whether there is an influence of p r e - C P R conditions. Mullie et aD 3 discussed that p r e - C P R conditions (underlying disease, p r e a r r e s t health status, location, type of cardiac arrest) significantly influence survival. In our study, the patients younger than 40 years shared characteristics significantly different from older age groups. Clinton et a122 r e p o r t e d that cardiac arrest victims younger the age of 40 years less frequently suffer a cardiac arrest of cardiac origin. Our data also suggest that these patients are more frequently fully functional before to the arrest and that arrests in patients aged younger than 40 years more often take place at public places. Elderly patients are more frequently struck by an arrest of cardiac origin at home, where their survival was significantly lower, and were frequently in a p o o r e r prearrest health state.iS In the out-of-hospital setting, it has been demonstrated that the p r e a r r e s t health state does not have an influence on survival. 13 The fact that p r e a r r e s t health state did not influence long-term survival in our study confirms the observation of other authors that (in-hospital) patients suffering a b a d general condition still have a considerable chance for survival and that this chance for survival is not influenced by age. a The prevalence of patients in ventricular fibrillation on a r r i v a l of the MICU team is low compared with other reports. 23 This can p r o b a b l y be explained by the relatively long response intervals of the Belgian EMS system. In a previous study, Bossaert et a124 observed that elderly cardiac arrest patients were less frequently resuscitated by bystanders and that b y s t a n d e r CPR might have a beneficial effect by maintaining more patients in ventricular fibrillation. 24 In p a r t , this might explain the observation that in elderly cardiac arrest patients, electromechanical dissociation and asystole was observed more frequently at arrival of the
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MICU. This difference in rhythms also was observed by other investigators. 25,26 Besides pre-CPR conditions, it is evident that response intervals have a significant effect on survival, z7 The Belgian EMS system has, compared with some other studies, r a t h e r long response times. 23 This is p r o b a b l y due to organizational differences in the EMS system, such as the density of MICU teams and the widespread use of a two-tiered system, ancient city centers with narrow streets, and a delayed notification of the EMS system by bystanders. Access and response intervals of BLS and ALS were significantly shorter in elderly patients, which might bias outcome results in different age groups. This age-related difference in out-of-hospital EMS response might be explaine~l because the registry included only cardiac arrests that received ALS. Indeed, no information is available on patients in whom ALS was not initiated. It is possible that there was less willingness to initiate ALS in elderly patients compared with younger subjects. A different attitude toward elderly patients and patients with a dependent lifestyle is evident from our analysis of the duration of ALS in unsuccessful CPR attempts. The d u r a tion of the CPR attempt has been considered by Nightingale and Grant 2s as a measure of actual practices during the attempt because guidelines on when to declare resuscitation efforts unsuccessful leave considerable room for individual discretion. It remains unclear whether the decision to cease CPR earlier in elderly and dependent patients was based on clinical findings or on p r o v i d e r decisions, to spare further suffering. CONCLUSION
Finally, we conclude that the chronologic age of a patient should not be used as the only determinant in the decision to withhold or to withdraw CPR. In cases without advance directives, the decision not to resuscitate should be based on a set of conditions that accurately predicts outcome and quality of survival. If known, the patient's wishes, the extent of the patient's disease(s), and the level of physical and mental function can be the most i m p o r t a n t determinants in decision making.5,n Unfortunately this information is not always available outside the hospital. In the hospital, however, a clear "DNR" policy that considers all admitted patients probably is the best prevention of unnecessary suffering by inappropriate CPR.
REFERENCES 1. Blakhall LJ: Must we always use CPR? NEoglJMed1987;317:1281,1284. 2. Taffet 6E, Teasdale TA, Luchi RJ: In-hospital cardiopulmonary resuscitation. JAMA 19881260:2069-2072. 3. Bear LS: Cardiopulmonary resuscitation after age fi5. Am J Cardio1197914311065. 4. Murphy DJ, Murray AM, Robinson BE, et al: Outcomes of cardiopulmonary resuscitation in the elderly. Ann Intern Med 19891111:199-205. 5. F[Jsgen I, Summa J-D: How much sense is there in an attempt to resuscitate an aged person? Gerontology1978;24:37-45. 6. Bayer A J, Ang BC, Pathy MSJ: Cardiac arrest in a geriatric unit. AgeAging 1985:14:271-276. 7. Gordon M, Hurowitz E: Cardiopulmonary resuscitation of the elderly. JAm GeriatrSoc 1984132:930-935. 8. Horsey CO, Fisher L: Why outcome of cardiopulmonary resuscitation in general wards is poor, Lancet 1982;1:31-34. 9. Bedell SE, Delbanco TL, Cook F, et ah Survival after cardiopulmonary resuscitation in the hospital. N Engl J Med 19831309:569-576. 10. Gulati RJ, Bhan GL, Horan MA: Cardiopulmonary resuscitation of old people. Lancet 198312:267-269. 11. Tresch DO, Thakur RK, Hoffmann RG, et al: Should the elderly be resuscitated following out-of-hospital cardiac arrest? Am J Met 1989;86:145-150. 12. Kannel WB, Thomas HE: Sudden coronary death: The Framingham study. Ann NY Acad Sol 1982;382:3-21. 13. Mullie A, Lewi P, Van Hoeyweghen R, et al: Pre-CPR conditions and the final outcome of CPR. Resuscitation 1989;17(suppl 1):11-21. 14. The Cerebral Resuscitation Study Group: The Belgian CPCR registry: Form protocol. Resuscitation 198911 (suppl):5-10. 15. Jennet B, Bond M: Assessment of outcome after severe brain damage: A practical scale. Lancet 197511:480-484. 16. Eisenberg MS, Hallstrem A, Bergner L: Long-term survival after out-of-hospital cardiac arrest. NEnglJMed19821306:1340-1343. 17. Baum RS, Alvarez H, Cobb LA: Survival after resuscitation from out-of-hospital ventricular fibrillation. Circulation 1974150:1231-1235. 18. Eisenberg M, Bergner L, Hallstrom A: Paramedic programs and out-of-hospital cardiac arrest t. Factors related with successful resuscitation. Am J Public Health 1979;69:30-38. 19. Weaver WD, Cobb LA, Hallstrom AP, et ah Factors influencing survival after out-ofhospital cardiac arrest. JAm Coil Cardio1198617:752-757. 20. Myerburg RJ, Condo CA, Sung RJ, et al: Clinical, electrophysiolegic and hemodynamic profile of patients resuscitated from prehospita] cardiac arrest. Am J Med 1980;68:568-576. 21. Safar P, Abramson N, Detre K, et al: Old age does not negate good outcome after cardiac arrest and CPR (abstract). CritCareMef11989;17:S13& 22. Clinton JE, Mc6ill J, Irwin G, et al: Cardiac arrest under age 40: Etiology and prognosis. Ann Emerg Med 1984113:1011-1015. 23. Weaver WD, Hill DH, Fahrenbruch CE, et al: Use of the automatic external defibrillator in the management of out-of-hospital cardiac arrest. N EnglJ Med 1988;319:661-666. 24. Bossaert L, Van Hoeyweghen R, Cerebral Resuscitation Study Group: Bystander CPR in out-of-hospital cardiac arrest. Resuscitation 1989117(suppl):S55-S69. 25. Tresch DO, Thakur RK, Hoffman R6, et al: Comparison of outcome of out-of-hospital cardiac arrest in persons younger and older than 70 years of age. Am J Cardiol 1988;61:1120-1122. 26. Suton-Tyrell K, Abramson NS, Safar P, et al: Predictors of electromechanical dissociation during cardiac arrest. Ann Emerg Med 1988;17:572-575. 27. Mullie A, Van Hoeyweghen R, Ouets A, et al: Influence of time intervals on outcome of CPR. Resuscitation 1989;17(suppl 1):23-33. 28. Nightingale SD, Grant M: Risk preference and decision making in critical care situations. Chest1988193:684-687.
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The Belgian Cerebral Resuscitation Study Group A Mullie P Martens PVerstringe Department of Critical Care Medicine Algameen Ziekenhuis Sint Jan Brugge
Address for reprints: Leo Bossaert, MD University of Antwerp-UlA Universiteitsplein 1 B 2610 Antwerp, Belgium
W Buylaert P Calle H Houbrechts Department of Emergency Medicine Universitair Ziekenhuis Gent L Come D Lauwaert Department of EmergencyMedicine Akademisch ZiekenhuisVrije Universiteit Brussels H Delooz H Verbruggen Department of EmergencyMedicine Universitair Ziekenhuis St RafaeI-Gasthuisberg Leuven R De Cock M Weeghmans Department of Emergency Medicine Imeldaziekenhuis, Bonheide J Mennes Department of EmergencyMedicine Jan Palfijn Ziekenhuis Merksem L Bossaert R Van Hoeyweghen Department of Intensive Care UIA Universitair Ziekenhuis Antwerp P Lewi A Quets Department of Information Sciences Janssen Research Foundation Beerse
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