CORRESPONDENCE
Prehospital Cardiac Arrest Therapy To the Editor." The article by Bonnin et al, "Outcomes in Unsuccessful Field Resuscitation A t t e m p t s " [May 1989;18:507-512[ states as a conclusion that "any adult nontraumatic cardiac arrest victim who does not respond to prehospital ACLS efforts should be pronounced dead at the scene." This conclusion, justified simply by the data presented, fails to take into account several arguments against such a policy. The neurologic and cardiac outcome of patients resuscitated in the emergency department after failed prehospital ACLS is not uniformly poor. There is a certain rate of intact neurologic survival in these patients, albeit low. A policy such as that suggested in this article will result in avoidable cardiovascular death. 0.6% of 181 patients does not seem to be significant. However, 0.6% of the 350,000 prehospital cardiovascular deaths that occur per year in the United States sheds a different light on the numbers involved. If we indeed have only 30 minutes in which to restore cardiovascular function, then perhaps we should look to change what we do in those 30 minutes in patients who are failing prehospital ACLS protocol. We have found (unpublished data) that 84% of prehospital cardiac arrests that survive to intact neurologic hospital discharge were resuscitated in the field after an airway, defibrillation, and 1 mg epinephrine. Patients who progress further along the ACLS protocol have a progressively decreased likelihood of survival. Perhaps we should transport immediately after the intubation, defibrillation, and 1 mg epinephrine have failed. At the hospital, such insufficiently tested therapeutic modalities as emergency partial cardiac bypass and open cardiac massage could be performed. Improving neurologic outcome through cerebral resuscitation is a science just emerging that may in the future play a significant role in shaping our attitude and approach to cardiac resuscitation. The point is that if what we are currently doing for refractory prehospital cardiac arrest is not working, it is time for new approaches. The history of medicine is replete with examples of disease processes that had equally dismal outcomes, only to be systematically and effectively solved.
Doug Brunette, MD Steve Sterner, MD Emergency Department Hennepin County Medical Center Minneapolis, Minnesota
In Reply: We appreciate the c o m m e n t s of Drs Brunette and Sterner and agree that there is a need for new approaches to the patient in preliospital cardiac arrest. The literature documents the futility of prolonged resuscitative effortsl, 2 as currently practiced. Changes in resuscitative protocols, such as higb-dose epinephrine, open-chest massage, or cardiac bypass, may yield better survival rates. Brunette and Sterner state, however, that the outcome from failed prehospital cardiac arrest resuscitation is not uniformly poor. That statement is supported neither by our data nor our review of the literature. We documented that no patient who received all ACLS protocol resuscitative efforts survived to hospital discharge. We cannot extrapolate our data to say that no patient will ever survive after failed prehospital efforts. We suggest that the risks of transport to our paramedics (and the public) outweigh the benefits of transporting a patient who has failed a complete effort. When prehospital resources are scarce, this futile effort may further compromise patient care to the community at large. Our conclusion from these data is that physicians must realize and accept the limitations of current cardiac arrest therapy in the prehospital setting. We owe our patients our best efforts, but we must also be able to accept when our efforts are futile.
Marni J Bonnin, MD Baylor College of Medicine City of Houston EMS Houston, Texas Robert A Swor, DO, FACEP Department of Emergency Medicine William Beaumont Hospital Royal Oak, Michigan
1. Smith JP, BodaiBI: Guidelines for discontinuingprehospital CPR in the emergency department - A review. Ann Emerg Med 1985;14:1093-1098. 2. Warner LL, HoffmanJR, BaraffLJ: Prognostic significance of field response in out-of-hospitalventricular fibrillation. Chest 1985;87:22-28.
Studies on Prehospital Pharmacologic Therapy To the Editor: In their article, "Pharmacologic Intervention in Prehospital Care: A Critical Appraisal" [February 1989;18: 192-196], Shuster and Chong "review the evidence concerning the effectiveness of prehospital pharmacologic in184/340
tervention." Fourteen studies regarding prehospital pharmacological intervention and one emergency department study are reviewed. The authors concluded "there is no evidence that any medication given by the prehospital
Annals of Emergency Medicine
19:3 March 1990
care provider is beneficial or cannot safely be delayed until arrival to the hospital." If an i n t e n t of the authors was to evaluate the safety and benefit of prehospital pharmacologic therapy, t h e y should have reviewed studies that compared one drug versus no t r e a t m e n t u n t i l ED arrival. T h i s w o u l d h a v e m o r e precisely answered the question instead of using studies comparing one t h e r a p e u t i c i n t e r v e n t i o n w i t h another. T h e trial of b r e t y l i u m for cardiac arrest ] was n o t a prehospital study, so conclusions about its use in the field m a y not be valid. Studies that are i n t e n d e d to d e t e r m i n e t h e safety and benefit of p r e h o s p i t a l t h e r a p y s h o u l d be l i m i t e d to the prehospital setting, where such factors as the l i m i t a t i o n s in paramedic's knowledge base and scope of practice, the prehospital environment, and earlier adm i n i s t r a t i o n of pharmacologic therapy m a y affect the results. R e m o v i n g the aforementioned studies from the review, five drugs r e m a i n : d e x a m e t h a s o n e for p u l s e l e s s idiov e n t r i c u l a r r h y t h m (PIVR}, c a l c i u m for e l e c t r o m e c h a n i c a l dissociation and asystole, atropine for refractory asystole or PIVR, lidocaine prophylaxis for suspected m y o c a r d i a l infarction, and streptokinase for acute m y o c a r d i a l infarction. The first two drugs were not r e c o m m e n d e d in the prehospital or ED m a n a g e m e n t of v i c t i m s of cardiac arrest at the t i m e the r e v i e w was s u b m i t t e d , z O n l y l i d o c a i n e p r o p h y l a x i s of s u s p e c t e d m y o c a r d i a l i n f a r c t i o n and atropine for refractory asystole or PIVR r e m a i n as standards of care,
If t h e a u t h o r s w i s h e d to r e v i e w c u r r e n t p r e h o s p i t a l p h a r m a c o l o g i c therapy, o n l y the s t u d i e s of a t r o p i n e for a s y s t o l e or PIVR, 3 l i d o c a i n e p r o p h y l a x i s , 4 a n d s t r e p t o k i n a s e for a c u t e m y o c a r d i a l i n f a r c t i o n 5 s h o u l d h a v e been included. As Shuster and Chong correctly p o i n t out, these studies are l i m i t e d by their small s a m p l e sizes. As a result, these studies could not rule out the p o s s i b i l i t y of an i m p r o v e d outcome. W h i l e t h e a u t h o r s ' s u m m a r y s t a t e m e n t regarding the lack of proven efficacy of prehospital pharmacologic therapy is correct, it should be judged by the data that support it - very little in this case. T h e p a u c i t y of prehospital r e s e a r c h on drug effectiveness does n o t p e r m i t m a k i n g any valid conclusions.
Stephen E Jones, MD Director, Prehospital Care Los Angeles County/USC Medical Center
Franklin D Pratt, MD Medical Director, Fire Department County of Los Angeles 1. Nowak RM, Bodnar TJ, Dronen S, et al: Bretylium tosylate as initial treatment for cardiopulmonary arrest: Randomized comparison with placebo. Ann ErnergMed 1981;10:404-407. 2. Standards and guidelines for cardiopuhrronary resuscitation (CPR) and emergency cardiac care (ECC). JAMA 1986;255:2905-2984. 3. Con GA, Clinton JE, Ruiz E: Use of atropine for bradyasystolic prehospital cardiac arrest. Ann EmergMed 1981;10:462-467. 4. Hargarten KM, Aprahamian C, Stueven HA, et al: Prophylactic lidocaine in the prehospital patient with chest pain of suspected cardiac origin. Arm EmergMed 1986;15:881-885. 5. villemant D, Barriot P, Riou B, et al: Achievement of thrombolysis at home in cases of acute myocardial infarction (letter). Lancet 1987;t: 228-229.
In Reply: Drs Jones and Pratt are quite correct. Studies to evaluate the safety and benefit of prehospital pharmacologic therapy should compare patients w h o receive prehospital drug therapy w i t h p a t i e n t s who receive no drugs u n t i l they arrive at the e m e r g e n c y department. The fact is that there are so few such studies that directly address the issue t h a t we expanded our analysis in order to assess even indirect evidence of the efficacy of prehospital pharmacologic therapy. We too concluded that there is no published scientific evidence on w h i c h to base an opinion about prehospital pharmacologic intervention. We are c u r r e n t l y u n d e r t a k i n g a three-year prospective trial to c o m p a r e o u t c o m e s in p a t i e n t s w i t h c h e s t p a i n w h o are e i t h e r g i v e n p h a r m a c o l o g i c t h e r a p y by paramedics or transported directly to the ED by BLS crews. We are able to e t h i c a l l y compare these two groups because in H a m i l t o n we have only enough ALS crews to reach 30% of Code 4 emergencies. We e n c o u r a g e o t h e r efforts to o b j e c t i v e l y assess t h e value of prehospital interventions.
Michael Shuster, MD, FRCP(C) Director, Paramedic Program John Chong, MD, FRCP(C) Department of Clinical Epidemiology & Biostatistics McMaster University Hamilton, Ontario, Canada
Tympanic Membrane Thermometers To the Editor: I read the a r t i c l e e n t i t l e d " E v a l u a t i o n of a T y m p a n i c M e m b r a n e T h e r m o m e t e r in an O u t p a t i e n t Clinical Sett i n g " [ S e p t e m b e r 1989;18:1004-1006] w i t h c o n s i d e r a b l e interest. However, the conclusions of the study are subject to c r i t i c i s m because of inadequate m e t h o d o l o g i c a l reporting of errors. First, a glass-mercury t h e r m o m e t e r requires more than t h e t h r e e to five m i n u t e s for e q u i l i b r a t i o n t h a t D r Ros 19:3 March 1990
used in his study.l, 2 Various reports of duration of therm o m e t e r p l a c e m e n t u n t i l achieving o p t i m a l t e m p e r a t u r e conclude that eight to ten m i n u t e s is best. 3 Children and afebrile adults require the longest equilibration times.4, 5 Secondly, because the p h y s i c i a n obtaining the t y m p a n i c t e m p e r a t u r e was reportedly n o t blinded to the results of oral or rectal temperature, the possibility of introducing bias in evaluating t e m p e r a t u r e correlation is raised.
Annals of Emergency Medicine
341/185
Prehospital Cardiac Arrest Therapy To the Editor." The article by Bonnin et al, "Outcomes in Unsuccessful Field Resuscitation A t t e m p t s " [May 1989;18:507-512[ states as a conclusion that "any adult nontraumatic cardiac arrest victim who does not respond to prehospital ACLS efforts should be pronounced dead at the scene." This conclusion, justified simply by the data presented, fails to take into account several arguments against such a policy. The neurologic and cardiac outcome of patients resuscitated in the emergency department after failed prehospital ACLS is not uniformly poor. There is a certain rate of intact neurologic survival in these patients, albeit low. A policy such as that suggested in this article will result in avoidable cardiovascular death. 0.6% of 181 patients does not seem to be significant. However, 0.6% of the 350,000 prehospital cardiovascular deaths that occur per year in the United States sheds a different light on the numbers involved. If we indeed have only 30 minutes in which to restore cardiovascular function, then perhaps we should look to change what we do in those 30 minutes in patients who are failing prehospital ACLS protocol. We have found (unpublished data) that 84% of prehospital cardiac arrests that survive to intact neurologic hospital discharge were resuscitated in the field after an airway, defibrillation, and 1 mg epinephrine. Patients who progress further along the ACLS protocol have a progressively decreased likelihood of survival. Perhaps we should transport immediately after the intubation, defibrillation, and 1 mg epinephrine have failed. At the hospital, such insufficiently tested therapeutic modalities as emergency partial cardiac bypass and open cardiac massage could be performed. Improving neurologic outcome through cerebral resuscitation is a science just emerging that may in the future play a significant role in shaping our attitude and approach to cardiac resuscitation. The point is that if what we are currently doing for refractory prehospital cardiac arrest is not working, it is time for new approaches. The history of medicine is replete with examples of disease processes that had equally dismal outcomes, only to be systematically and effectively solved.
Doug Brunette, MD Steve Sterner, MD Emergency Department Hennepin County Medical Center Minneapolis, Minnesota
In Reply: We appreciate the c o m m e n t s of Drs Brunette and Sterner and agree that there is a need for new approaches to the patient in preliospital cardiac arrest. The literature documents the futility of prolonged resuscitative effortsl, 2 as currently practiced. Changes in resuscitative protocols, such as higb-dose epinephrine, open-chest massage, or cardiac bypass, may yield better survival rates. Brunette and Sterner state, however, that the outcome from failed prehospital cardiac arrest resuscitation is not uniformly poor. That statement is supported neither by our data nor our review of the literature. We documented that no patient who received all ACLS protocol resuscitative efforts survived to hospital discharge. We cannot extrapolate our data to say that no patient will ever survive after failed prehospital efforts. We suggest that the risks of transport to our paramedics (and the public) outweigh the benefits of transporting a patient who has failed a complete effort. When prehospital resources are scarce, this futile effort may further compromise patient care to the community at large. Our conclusion from these data is that physicians must realize and accept the limitations of current cardiac arrest therapy in the prehospital setting. We owe our patients our best efforts, but we must also be able to accept when our efforts are futile.
Marni J Bonnin, MD Baylor College of Medicine City of Houston EMS Houston, Texas Robert A Swor, DO, FACEP Department of Emergency Medicine William Beaumont Hospital Royal Oak, Michigan
1. Smith JP, BodaiBI: Guidelines for discontinuingprehospital CPR in the emergency department - A review. Ann Emerg Med 1985;14:1093-1098. 2. Warner LL, HoffmanJR, BaraffLJ: Prognostic significance of field response in out-of-hospitalventricular fibrillation. Chest 1985;87:22-28.
Studies on Prehospital Pharmacologic Therapy To the Editor: In their article, "Pharmacologic Intervention in Prehospital Care: A Critical Appraisal" [February 1989;18: 192-196], Shuster and Chong "review the evidence concerning the effectiveness of prehospital pharmacologic in184/340
tervention." Fourteen studies regarding prehospital pharmacological intervention and one emergency department study are reviewed. The authors concluded "there is no evidence that any medication given by the prehospital
Annals of Emergency Medicine
19:3 March 1990
care provider is beneficial or cannot safely be delayed until arrival to the hospital." If an i n t e n t of the authors was to evaluate the safety and benefit of prehospital pharmacologic therapy, t h e y should have reviewed studies that compared one drug versus no t r e a t m e n t u n t i l ED arrival. T h i s w o u l d h a v e m o r e precisely answered the question instead of using studies comparing one t h e r a p e u t i c i n t e r v e n t i o n w i t h another. T h e trial of b r e t y l i u m for cardiac arrest ] was n o t a prehospital study, so conclusions about its use in the field m a y not be valid. Studies that are i n t e n d e d to d e t e r m i n e t h e safety and benefit of p r e h o s p i t a l t h e r a p y s h o u l d be l i m i t e d to the prehospital setting, where such factors as the l i m i t a t i o n s in paramedic's knowledge base and scope of practice, the prehospital environment, and earlier adm i n i s t r a t i o n of pharmacologic therapy m a y affect the results. R e m o v i n g the aforementioned studies from the review, five drugs r e m a i n : d e x a m e t h a s o n e for p u l s e l e s s idiov e n t r i c u l a r r h y t h m (PIVR}, c a l c i u m for e l e c t r o m e c h a n i c a l dissociation and asystole, atropine for refractory asystole or PIVR, lidocaine prophylaxis for suspected m y o c a r d i a l infarction, and streptokinase for acute m y o c a r d i a l infarction. The first two drugs were not r e c o m m e n d e d in the prehospital or ED m a n a g e m e n t of v i c t i m s of cardiac arrest at the t i m e the r e v i e w was s u b m i t t e d , z O n l y l i d o c a i n e p r o p h y l a x i s of s u s p e c t e d m y o c a r d i a l i n f a r c t i o n and atropine for refractory asystole or PIVR r e m a i n as standards of care,
If t h e a u t h o r s w i s h e d to r e v i e w c u r r e n t p r e h o s p i t a l p h a r m a c o l o g i c therapy, o n l y the s t u d i e s of a t r o p i n e for a s y s t o l e or PIVR, 3 l i d o c a i n e p r o p h y l a x i s , 4 a n d s t r e p t o k i n a s e for a c u t e m y o c a r d i a l i n f a r c t i o n 5 s h o u l d h a v e been included. As Shuster and Chong correctly p o i n t out, these studies are l i m i t e d by their small s a m p l e sizes. As a result, these studies could not rule out the p o s s i b i l i t y of an i m p r o v e d outcome. W h i l e t h e a u t h o r s ' s u m m a r y s t a t e m e n t regarding the lack of proven efficacy of prehospital pharmacologic therapy is correct, it should be judged by the data that support it - very little in this case. T h e p a u c i t y of prehospital r e s e a r c h on drug effectiveness does n o t p e r m i t m a k i n g any valid conclusions.
Stephen E Jones, MD Director, Prehospital Care Los Angeles County/USC Medical Center
Franklin D Pratt, MD Medical Director, Fire Department County of Los Angeles 1. Nowak RM, Bodnar TJ, Dronen S, et al: Bretylium tosylate as initial treatment for cardiopulmonary arrest: Randomized comparison with placebo. Ann ErnergMed 1981;10:404-407. 2. Standards and guidelines for cardiopuhrronary resuscitation (CPR) and emergency cardiac care (ECC). JAMA 1986;255:2905-2984. 3. Con GA, Clinton JE, Ruiz E: Use of atropine for bradyasystolic prehospital cardiac arrest. Ann EmergMed 1981;10:462-467. 4. Hargarten KM, Aprahamian C, Stueven HA, et al: Prophylactic lidocaine in the prehospital patient with chest pain of suspected cardiac origin. Arm EmergMed 1986;15:881-885. 5. villemant D, Barriot P, Riou B, et al: Achievement of thrombolysis at home in cases of acute myocardial infarction (letter). Lancet 1987;t: 228-229.
In Reply: Drs Jones and Pratt are quite correct. Studies to evaluate the safety and benefit of prehospital pharmacologic therapy should compare patients w h o receive prehospital drug therapy w i t h p a t i e n t s who receive no drugs u n t i l they arrive at the e m e r g e n c y department. The fact is that there are so few such studies that directly address the issue t h a t we expanded our analysis in order to assess even indirect evidence of the efficacy of prehospital pharmacologic therapy. We too concluded that there is no published scientific evidence on w h i c h to base an opinion about prehospital pharmacologic intervention. We are c u r r e n t l y u n d e r t a k i n g a three-year prospective trial to c o m p a r e o u t c o m e s in p a t i e n t s w i t h c h e s t p a i n w h o are e i t h e r g i v e n p h a r m a c o l o g i c t h e r a p y by paramedics or transported directly to the ED by BLS crews. We are able to e t h i c a l l y compare these two groups because in H a m i l t o n we have only enough ALS crews to reach 30% of Code 4 emergencies. We e n c o u r a g e o t h e r efforts to o b j e c t i v e l y assess t h e value of prehospital interventions.
Michael Shuster, MD, FRCP(C) Director, Paramedic Program John Chong, MD, FRCP(C) Department of Clinical Epidemiology & Biostatistics McMaster University Hamilton, Ontario, Canada
Tympanic Membrane Thermometers To the Editor: I read the a r t i c l e e n t i t l e d " E v a l u a t i o n of a T y m p a n i c M e m b r a n e T h e r m o m e t e r in an O u t p a t i e n t Clinical Sett i n g " [ S e p t e m b e r 1989;18:1004-1006] w i t h c o n s i d e r a b l e interest. However, the conclusions of the study are subject to c r i t i c i s m because of inadequate m e t h o d o l o g i c a l reporting of errors. First, a glass-mercury t h e r m o m e t e r requires more than t h e t h r e e to five m i n u t e s for e q u i l i b r a t i o n t h a t D r Ros 19:3 March 1990
used in his study.l, 2 Various reports of duration of therm o m e t e r p l a c e m e n t u n t i l achieving o p t i m a l t e m p e r a t u r e conclude that eight to ten m i n u t e s is best. 3 Children and afebrile adults require the longest equilibration times.4, 5 Secondly, because the p h y s i c i a n obtaining the t y m p a n i c t e m p e r a t u r e was reportedly n o t blinded to the results of oral or rectal temperature, the possibility of introducing bias in evaluating t e m p e r a t u r e correlation is raised.
Annals of Emergency Medicine
341/185
