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Medical reliability of advanced prehospital cardiac life support
ORIGINAL CONTRIBUTION advanced cardiac life support, emergency medical services, reliability of; emergency medical services, advanced cardiac life support, reliability of
Medical Reliability of Advanced Prehospital Cardiac Life Support Records of 263 consecutive patients receiving prehospitul advanced cardiac hie support for dysrhythmias associated with clinical cardiac arrest were reviewed to determine I) accuracy of diagnosis of presenting rhythm by the paramedic in the field and the medical control physician at the telemetry base station; and 2) whether the treatment rendered was appropriate. The initial rhythm was misinterpreted by the paramedic in 41 patients (16%) and by the medical control physician in 22 patients (11%). In 16 patients (8%) both paramedic and physician misinterpreted the initial rhythm. Treatment errors occurred in I20 patients (46%). Forty-seven errors (18%) resulted from failure to establish an intravenous line, 17 (6%) resulted from failure to secure a controlled airway, and 38 (t4%) were medication errors from failure to adhere to protocol We conclude that errors in management of prehospital cardiac arrest victims in our emergency medical services system result most often from mistakes in specific therapy rather than from failure to identify the precipitating dysrhythmia. [Peacock JB, Blackwell VH, Wainscott M: Medical reliability of advanced prehospitul cardiac life support. Ann Emerg Med May 1985;i4:407-409.]
INTRODUCTION Since Pantridge's demonstration of the efficacy of advanced prehospital care for critically ill and injured patients more than two decades ago in Great Britain, more than 300 organized emergency medical services (EMS) systems providing advanced cardiac life support (ACLS) in the prehospital setting have been established in the United States.i, 2 Despite recommendations from nationally recognized authorities for online physician direction of prehospital paramedic activities, there is considerable variation in the immediacy of physician interaction in such activities. Furthermore, the efficacy of model systems that provide online medical direction by radio-telemetry remains unproven.3,4 Our study examines the reliability of online medical control of paramedic services in the prehospital treatment of clinical cardiac arrest in an urban setting.
Jack B Peacock, MD Virginia H Blackwell, RN Michael Wainscott, MD El Paso, Texas From the Department of Surgery, Division of Trauma and Emergency Medicine, Texas Tech University of Medicine, El Paso, Texas. Received for publication May 30, 1984. Accepted for publication July 30, 1984. Presented at the University Association for Emergency Medicine Annual Meeting in Louisville, Kentucky, May 1984. Address for reprints: Jack B Peacock, MD, Texas Tech Unive~'sity School of Medicine, 4800 Alberta Avenue, El Paso, Texas 79905.
METHODS The E1 Paso Emergency Medical Services System (EPEMSS) is an urban municipal service employing full-time emergency medical technicians. All medical direction and advanced (paramedic) training for employees is provided by the Division of Trauma and Emergency Medicine of the Department of Surgery at the Texas Tech Regional Academic Health Center. Operational protocols governing prehospital EMS services have been developed by division faculty in conjunction with EPEMSS. Protocols for ACLS in the field have been adapted from those developed by the American Heart Association.4 Medical control for EPEMSS, including advanced life support activities, is provided through a radio-telemetry base station in the emergency department of the affiliated teaching hospital. All physicians involved have been certified at the provider or instructor level in AGLS by the American Heart Association, and they have received special instruction in the nuances of EPEMSS protocols. Records of each prehospital ACLS event are completed separately by the 14:5 May 1985
Annals of Emergency Medicine
407/47
PREHOSPITAL CARDIAC LIFE SUPPORT Peacock, Blackwell & Wainscott
TABLE 1. Arrhythmia identification
Rhythm All
Asystole Ventricular fibrillation
Other
Paramedic Correct (%) 213/254 (84) 116/126 (92) 58/72 (81) 39/57 (68)
paramedics and the medical control physician(s). Each includes a copy of the initial rhythm strip, obtained in the field and at the telemetry base station, and a w r i t t e n chronology of events, observations, and treatment. During the test period (January 1983 through February 1984) 309 patients underwent prehospital treatment by EPEMSS for clinical cardiac arrest. In 46 patients, arrest was secondary to injury; these patients were excluded from the study. Records of the remaining 263 Patients were reviewed by the authors to determine 1) accuracy of diagnosis of the patient's presenting rhythm by the paramedic; 2) accuracy of diagnosis of the presenting rhythm by the medical control physician; and 3) appropriateness of prehospital care rendered. Statistical analysis of the data was performed using the exact binomial test for probabilities; P K .05 was considered significant.
RESULTS The series included 173 male patients and 90 female patients ranging in age from 3 months to 95 years (average, .65.11 years). Of these pat i e n t s , 129 (49%} p r e s e n t e d in asystole, 71 (27%) with ventricular fibrillation (VF), and 63 (24%) with other rhythms (electromechanical dissociation, severe bradycardia, tachycardia, agonal rhythm). The presenting rhythm was identified correctly by the paramedic in attendance in 213 of 254 i n s t a n c e s (84%), by the medical control physician in 174 of 196 patients (89%), and by both the paramedic and physician in 161 of 194 cases (83%). In 17 patients (8.8%) either the paramedic or the physician did not identify the patient's presenting rhythm. In 16 patients (8.2%) both the physician and 48/408
Physician Correct (%) 174/196 (89) 97/103 (94) 45/52 (87) 32/41 (78)
paramedic failed to identify correctly the precipitating arrhythmia (Table 1). The paramedic correctly identified asystole in 116 of 126 patients (92%), VF in 58 of 72 (80.6%), and other rhythms in 39 of 57 (68%). The medical control physician correctly identified asystole in 97 of 103 instances (94%), VF in 45 of 52 patients (86.5%), and other life-threatening rhythms in 32 of 41 cases (78%). Asystole was identified correctly by both the paramedic and the physician in 91 of 101 patients (90%), VF in 41 of 51 (80.4%), and other rhythms in 28 of 40 cases (70%). Both failed to identify asystole in four patients (4%), VF in six patients (12%), and other rhythms in six patients (15%). T h e r e were no s i g n i f i c a n t differences between the paramedics' and the physicians' ability to identify presenting rhythms. Treatment errors were identified in 120 of 263 cases (46%) (Table 2). The following were 82 instances (31%) in which diagnostic or therapeutic errors were considered to have seriously compromised patient care: misdiagnosis of rhythm in 16 patients (6%); failure to establish an intravenous (IV) line in 47 patients (18%); failure to secure an airway in 17 (6.4%); and equipment failures in two instances. There were m i n o r deviations from protocol in the administration of medications in 38 patients (14%) (nonprotocol medications were ordered or m e d i c a t i o n was given out of sequence). Sixteen patients (6%) were treated for the wrong rhythm. In nine patients VF was neither recognized nor appropriately treated by defibrillation. Three patients with ventricular tachycardia and three patients with bradycardias were not treated in accordance with the appropriate protocol. In one instance severe sinus tachycarAnnals of Emergency Medicine
Both Correct (%) 161/194 (83) 91/101 (90) 41/51 (80) 28/40 (70)
Neither Correct (%) 16/194 (8) 4/101 (4) 6/51 (12) 6/40 (15)
TABLE 2. Treatment errors
Error Type No IV No airway Medications Misdiagnosis Other Total
No. (%) 47 (18) 17 (06) 38 (14) 16 (06) 2 (<1) 120 (46)
dia was treated as ventricular tachycardia.
DISCUSSION There are numerous reports documenting the efficacy of advanced-level prehospital care for victims of cardiac arrest. 2 Among the factors reported to influence patient survival are the following: 1) etiology of arrest (cardiac vs noncardiac); 2) patient age and sex; 3) t i m e f r o m arrest to initial care and to definitive care; 4) precipitating rhythm; and 5) level of prehospital care.
Few studies have examined the role of physician medical direction or the caliber of care given by the nonphysician provider. Pozen and coworkers, in a study of prehospital care of 288 acutely ill cardiac patients in Massachusetts, reported that 35% of cardiac dysrhythmias were interpreted incorrectly by both the paramedics involved and their medical control physician; in addition, t r e a t m e n t protocols were not adhered to in 26% of cases, s Where life-threatening dysr h y t h m i a s were i n v o l v e d (agonal rhythm, premature ventricular contractions, ventricular tachycardia/ fibrillation), only 39% of patients were diagnosed and treated correctly, compared to 77% for the entire group. A114:5 May 1985
though overall m o r t a l i t y was adversely affected, the i m p a c t of diagnostic and treatment errors on m o r t a l i t y was of marginal significance. Our study d e a l s o n l y w i t h lifethreatening dysrhythmias resulting in clinical cardiac arrest; it does not examine m o r t a l i t y . T h e p r e c i p i t a t i n g dysrhythmia a m o n g t h e p a t i e n t s in our series was not identified by either the paramedic or the physician in only 6% of cases. In our series, 54% of patients were diagnosed and treated correctly. If m i n o r deviations from protocol are e l i m i n a t e d from consideration, correct diagnosis and treatment were rendered in 69% of patients. The differences between our results and those of Pozen might be explained by system configuration and training of personnel. T h e m a j o r i t y of paramedics in our s y s t e m received their advanced training in a single institution, and t h e p h y s i c i a n s p r o v i d i n g medical control in our s y s t e m have participated in that training. In addition, local testing and certification in advanced skills are required of all paramedics in our s y s t e m ; c o n t i n u i n g education and p e r i o d i c r e t e s t i n g of knowledge and skills under the aegis of the training institution are requirements for continued certification. All physicians in our s y s t e m have been certified in ACLS at the provider or instructor level by the A m e r i c a n Heart Association, and all are trained emergency physicians or emergency medicine residents. All m e d i c a l control and medical direction for the system emanate from a single sponsor hospital. The P o z e n s t u d y i n v o l v e d a m bulance s e r v i c e s f r o m 20 c o m m u -
14:5 May 1985
nities in a p r e d o m i n a n t l y rural setting. Medical control was issued from one of three receiving hospitals in the region, and the medical control physicians' backgrounds ranged from training in surgery and internal medicine to formal training in emergency medicine. The majority of treatment errors in our series resulted from a paramedic's inability to establish an IV lifeline or to secure the patient's airway (77% of errors, 24% of patients}. Current policy in our system limits the number of attempts the paramedic m a y m a k e to start an IV line or to intubate the patient because of short scene-to-hospital distances. Reports from other systems and unpublished data from our own system support the observation that p a t i e n t survival is inversely correlated w i t h out-of-hospital treatment time. 6 Given the short distances involved in our system, we have reasoned that early transport to the hospital m a y be a m o r e i m p o r t a n t d e t e r m i n a n t of survival t h a n are comprehensive efforts at resuscitation in the field. Minor deviations from protocol occurred in 14% of patients; these included p h y s i c i a n orders for a d m i n istration of nonprotocol m e d i c a t i o n s or failure to order or administer medications in the proper sequence. While these errors were not considered grave d e v i a t i o n s f r o m policy, t h e i r occurrence reflects the need for continued m o n i t o r i n g of m e d i c a l control functions, even in a relatively controlled environment. CONCLUSION Errors in the prehospital manage-
Annals of Emergency Medicine
m e n t of cardiac arrest u s u a l l y result from errors in specific therapy rather than from failure to identify the precipitating dysrhythmia. Most often t r e a t m e n t errors r e s u l t f r o m an inability on the part of the initial provider to successfully establish an IV lifeline. Ongoing m o n i t o r i n g of syst e m performance to detect diagnostic and m a n a g e m e n t errors is essential, and provides a database for improvem e n t of system performance and patient care.
REFERENCES 1. Pantridge JF, Geddes JS: A mobile intensive care unit in the management of myocardial infarction. Lancet 1967;2: 271-273. 2. Eisenberg MS, Bergner L, Hearne T: Out-of-hospital cardiac arrest: A review of major studies and a proposed uniform reporting system. A m J Public Health 1980; 70:236-240. 3. Boyd D: Federal Emergency Medical Services Guidelines. Washington, DC, Federal Office of Emergency Medical Services, 1978. 4. Lambrew CT, Carveth SW, McIntyre KM: Advanced cardiac life support in perspective, in McIntyre KM, Lewis AJ (eds): Textbook of Advanced Cardiac Life Support. Dallas, American Heart Association, 1981, pp 11-18. 5. Pozen MW, D'Agostino R.B, Sytkowski PA, et al: Effectiveness of a prehospital medical control system: An analysis of the interaction between emergency room physician and paramedic. Circulation 1981;63:442-447. 6. Pionkowski RS, Thompson BM, Gruchow HW, et al: Resuscitation time in ventricular fibrillation - - A prognostic indicator. Ann Emerg Med 1983;12:733-738.
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Medical Reliability of Advanced Prehospital Cardiac Life Support Records of 263 consecutive patients receiving prehospitul advanced cardiac hie support for dysrhythmias associated with clinical cardiac arrest were reviewed to determine I) accuracy of diagnosis of presenting rhythm by the paramedic in the field and the medical control physician at the telemetry base station; and 2) whether the treatment rendered was appropriate. The initial rhythm was misinterpreted by the paramedic in 41 patients (16%) and by the medical control physician in 22 patients (11%). In 16 patients (8%) both paramedic and physician misinterpreted the initial rhythm. Treatment errors occurred in I20 patients (46%). Forty-seven errors (18%) resulted from failure to establish an intravenous line, 17 (6%) resulted from failure to secure a controlled airway, and 38 (t4%) were medication errors from failure to adhere to protocol We conclude that errors in management of prehospital cardiac arrest victims in our emergency medical services system result most often from mistakes in specific therapy rather than from failure to identify the precipitating dysrhythmia. [Peacock JB, Blackwell VH, Wainscott M: Medical reliability of advanced prehospitul cardiac life support. Ann Emerg Med May 1985;i4:407-409.]
INTRODUCTION Since Pantridge's demonstration of the efficacy of advanced prehospital care for critically ill and injured patients more than two decades ago in Great Britain, more than 300 organized emergency medical services (EMS) systems providing advanced cardiac life support (ACLS) in the prehospital setting have been established in the United States.i, 2 Despite recommendations from nationally recognized authorities for online physician direction of prehospital paramedic activities, there is considerable variation in the immediacy of physician interaction in such activities. Furthermore, the efficacy of model systems that provide online medical direction by radio-telemetry remains unproven.3,4 Our study examines the reliability of online medical control of paramedic services in the prehospital treatment of clinical cardiac arrest in an urban setting.
Jack B Peacock, MD Virginia H Blackwell, RN Michael Wainscott, MD El Paso, Texas From the Department of Surgery, Division of Trauma and Emergency Medicine, Texas Tech University of Medicine, El Paso, Texas. Received for publication May 30, 1984. Accepted for publication July 30, 1984. Presented at the University Association for Emergency Medicine Annual Meeting in Louisville, Kentucky, May 1984. Address for reprints: Jack B Peacock, MD, Texas Tech Unive~'sity School of Medicine, 4800 Alberta Avenue, El Paso, Texas 79905.
METHODS The E1 Paso Emergency Medical Services System (EPEMSS) is an urban municipal service employing full-time emergency medical technicians. All medical direction and advanced (paramedic) training for employees is provided by the Division of Trauma and Emergency Medicine of the Department of Surgery at the Texas Tech Regional Academic Health Center. Operational protocols governing prehospital EMS services have been developed by division faculty in conjunction with EPEMSS. Protocols for ACLS in the field have been adapted from those developed by the American Heart Association.4 Medical control for EPEMSS, including advanced life support activities, is provided through a radio-telemetry base station in the emergency department of the affiliated teaching hospital. All physicians involved have been certified at the provider or instructor level in AGLS by the American Heart Association, and they have received special instruction in the nuances of EPEMSS protocols. Records of each prehospital ACLS event are completed separately by the 14:5 May 1985
Annals of Emergency Medicine
407/47
PREHOSPITAL CARDIAC LIFE SUPPORT Peacock, Blackwell & Wainscott
TABLE 1. Arrhythmia identification
Rhythm All
Asystole Ventricular fibrillation
Other
Paramedic Correct (%) 213/254 (84) 116/126 (92) 58/72 (81) 39/57 (68)
paramedics and the medical control physician(s). Each includes a copy of the initial rhythm strip, obtained in the field and at the telemetry base station, and a w r i t t e n chronology of events, observations, and treatment. During the test period (January 1983 through February 1984) 309 patients underwent prehospital treatment by EPEMSS for clinical cardiac arrest. In 46 patients, arrest was secondary to injury; these patients were excluded from the study. Records of the remaining 263 Patients were reviewed by the authors to determine 1) accuracy of diagnosis of the patient's presenting rhythm by the paramedic; 2) accuracy of diagnosis of the presenting rhythm by the medical control physician; and 3) appropriateness of prehospital care rendered. Statistical analysis of the data was performed using the exact binomial test for probabilities; P K .05 was considered significant.
RESULTS The series included 173 male patients and 90 female patients ranging in age from 3 months to 95 years (average, .65.11 years). Of these pat i e n t s , 129 (49%} p r e s e n t e d in asystole, 71 (27%) with ventricular fibrillation (VF), and 63 (24%) with other rhythms (electromechanical dissociation, severe bradycardia, tachycardia, agonal rhythm). The presenting rhythm was identified correctly by the paramedic in attendance in 213 of 254 i n s t a n c e s (84%), by the medical control physician in 174 of 196 patients (89%), and by both the paramedic and physician in 161 of 194 cases (83%). In 17 patients (8.8%) either the paramedic or the physician did not identify the patient's presenting rhythm. In 16 patients (8.2%) both the physician and 48/408
Physician Correct (%) 174/196 (89) 97/103 (94) 45/52 (87) 32/41 (78)
paramedic failed to identify correctly the precipitating arrhythmia (Table 1). The paramedic correctly identified asystole in 116 of 126 patients (92%), VF in 58 of 72 (80.6%), and other rhythms in 39 of 57 (68%). The medical control physician correctly identified asystole in 97 of 103 instances (94%), VF in 45 of 52 patients (86.5%), and other life-threatening rhythms in 32 of 41 cases (78%). Asystole was identified correctly by both the paramedic and the physician in 91 of 101 patients (90%), VF in 41 of 51 (80.4%), and other rhythms in 28 of 40 cases (70%). Both failed to identify asystole in four patients (4%), VF in six patients (12%), and other rhythms in six patients (15%). T h e r e were no s i g n i f i c a n t differences between the paramedics' and the physicians' ability to identify presenting rhythms. Treatment errors were identified in 120 of 263 cases (46%) (Table 2). The following were 82 instances (31%) in which diagnostic or therapeutic errors were considered to have seriously compromised patient care: misdiagnosis of rhythm in 16 patients (6%); failure to establish an intravenous (IV) line in 47 patients (18%); failure to secure an airway in 17 (6.4%); and equipment failures in two instances. There were m i n o r deviations from protocol in the administration of medications in 38 patients (14%) (nonprotocol medications were ordered or m e d i c a t i o n was given out of sequence). Sixteen patients (6%) were treated for the wrong rhythm. In nine patients VF was neither recognized nor appropriately treated by defibrillation. Three patients with ventricular tachycardia and three patients with bradycardias were not treated in accordance with the appropriate protocol. In one instance severe sinus tachycarAnnals of Emergency Medicine
Both Correct (%) 161/194 (83) 91/101 (90) 41/51 (80) 28/40 (70)
Neither Correct (%) 16/194 (8) 4/101 (4) 6/51 (12) 6/40 (15)
TABLE 2. Treatment errors
Error Type No IV No airway Medications Misdiagnosis Other Total
No. (%) 47 (18) 17 (06) 38 (14) 16 (06) 2 (<1) 120 (46)
dia was treated as ventricular tachycardia.
DISCUSSION There are numerous reports documenting the efficacy of advanced-level prehospital care for victims of cardiac arrest. 2 Among the factors reported to influence patient survival are the following: 1) etiology of arrest (cardiac vs noncardiac); 2) patient age and sex; 3) t i m e f r o m arrest to initial care and to definitive care; 4) precipitating rhythm; and 5) level of prehospital care.
Few studies have examined the role of physician medical direction or the caliber of care given by the nonphysician provider. Pozen and coworkers, in a study of prehospital care of 288 acutely ill cardiac patients in Massachusetts, reported that 35% of cardiac dysrhythmias were interpreted incorrectly by both the paramedics involved and their medical control physician; in addition, t r e a t m e n t protocols were not adhered to in 26% of cases, s Where life-threatening dysr h y t h m i a s were i n v o l v e d (agonal rhythm, premature ventricular contractions, ventricular tachycardia/ fibrillation), only 39% of patients were diagnosed and treated correctly, compared to 77% for the entire group. A114:5 May 1985
though overall m o r t a l i t y was adversely affected, the i m p a c t of diagnostic and treatment errors on m o r t a l i t y was of marginal significance. Our study d e a l s o n l y w i t h lifethreatening dysrhythmias resulting in clinical cardiac arrest; it does not examine m o r t a l i t y . T h e p r e c i p i t a t i n g dysrhythmia a m o n g t h e p a t i e n t s in our series was not identified by either the paramedic or the physician in only 6% of cases. In our series, 54% of patients were diagnosed and treated correctly. If m i n o r deviations from protocol are e l i m i n a t e d from consideration, correct diagnosis and treatment were rendered in 69% of patients. The differences between our results and those of Pozen might be explained by system configuration and training of personnel. T h e m a j o r i t y of paramedics in our s y s t e m received their advanced training in a single institution, and t h e p h y s i c i a n s p r o v i d i n g medical control in our s y s t e m have participated in that training. In addition, local testing and certification in advanced skills are required of all paramedics in our s y s t e m ; c o n t i n u i n g education and p e r i o d i c r e t e s t i n g of knowledge and skills under the aegis of the training institution are requirements for continued certification. All physicians in our s y s t e m have been certified in ACLS at the provider or instructor level by the A m e r i c a n Heart Association, and all are trained emergency physicians or emergency medicine residents. All m e d i c a l control and medical direction for the system emanate from a single sponsor hospital. The P o z e n s t u d y i n v o l v e d a m bulance s e r v i c e s f r o m 20 c o m m u -
14:5 May 1985
nities in a p r e d o m i n a n t l y rural setting. Medical control was issued from one of three receiving hospitals in the region, and the medical control physicians' backgrounds ranged from training in surgery and internal medicine to formal training in emergency medicine. The majority of treatment errors in our series resulted from a paramedic's inability to establish an IV lifeline or to secure the patient's airway (77% of errors, 24% of patients}. Current policy in our system limits the number of attempts the paramedic m a y m a k e to start an IV line or to intubate the patient because of short scene-to-hospital distances. Reports from other systems and unpublished data from our own system support the observation that p a t i e n t survival is inversely correlated w i t h out-of-hospital treatment time. 6 Given the short distances involved in our system, we have reasoned that early transport to the hospital m a y be a m o r e i m p o r t a n t d e t e r m i n a n t of survival t h a n are comprehensive efforts at resuscitation in the field. Minor deviations from protocol occurred in 14% of patients; these included p h y s i c i a n orders for a d m i n istration of nonprotocol m e d i c a t i o n s or failure to order or administer medications in the proper sequence. While these errors were not considered grave d e v i a t i o n s f r o m policy, t h e i r occurrence reflects the need for continued m o n i t o r i n g of m e d i c a l control functions, even in a relatively controlled environment. CONCLUSION Errors in the prehospital manage-
Annals of Emergency Medicine
m e n t of cardiac arrest u s u a l l y result from errors in specific therapy rather than from failure to identify the precipitating dysrhythmia. Most often t r e a t m e n t errors r e s u l t f r o m an inability on the part of the initial provider to successfully establish an IV lifeline. Ongoing m o n i t o r i n g of syst e m performance to detect diagnostic and m a n a g e m e n t errors is essential, and provides a database for improvem e n t of system performance and patient care.
REFERENCES 1. Pantridge JF, Geddes JS: A mobile intensive care unit in the management of myocardial infarction. Lancet 1967;2: 271-273. 2. Eisenberg MS, Bergner L, Hearne T: Out-of-hospital cardiac arrest: A review of major studies and a proposed uniform reporting system. A m J Public Health 1980; 70:236-240. 3. Boyd D: Federal Emergency Medical Services Guidelines. Washington, DC, Federal Office of Emergency Medical Services, 1978. 4. Lambrew CT, Carveth SW, McIntyre KM: Advanced cardiac life support in perspective, in McIntyre KM, Lewis AJ (eds): Textbook of Advanced Cardiac Life Support. Dallas, American Heart Association, 1981, pp 11-18. 5. Pozen MW, D'Agostino R.B, Sytkowski PA, et al: Effectiveness of a prehospital medical control system: An analysis of the interaction between emergency room physician and paramedic. Circulation 1981;63:442-447. 6. Pionkowski RS, Thompson BM, Gruchow HW, et al: Resuscitation time in ventricular fibrillation - - A prognostic indicator. Ann Emerg Med 1983;12:733-738.
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