CORRESPONDENCE
Much like the fable of three blind men with completely different descriptions of the same elephant, each viewpoint may be completely accurate, while the larger truth involves the merger of multiple descriptions. I described a basic science foundation in resuscitation as a unifying p a t h o p h y s i o l o g i c focus for emergency medicine. Dr Schwab prefers to focus on cost-effective, high-quality health care delivery for patients. Others have alternatively suggested that we should focus on the subtlety and variety of disease presentation or on the range of required diagnostic skills. My view of the genesis of emergency medicine in the treatment of shock and acute hypotension is shared by others. Dr B Ken Gray, past president of the American College of Emergency Physicians, writes, "We are all familiar with the origins of emergency medicine. The battlefield medical systems of Korea and Vietnam taught us more about the practice than any system prior to that time. Triage systems, quick stabilization methods, and emergency surgery procedures were employed to save the lives of soldiers injured in battle. 'q The message of my editorial, however, was not that resuscitation should become the single focus of emergency medicine but that we now need to emphasize and develop basic science research in order to augment existing patient care, teaching, and clinical research. Obviously, research in resuscitation should not exclude all other research, nor should clinical research be seen as less important or valuable for our future than basic science research. But let us be clear: there is currently almost no basic science research within emergency medicine. This is to be expected in an emerging specialty, but to assure our growth and maturation it is now crucial for us to establish the link between clinical resuscitation and the basic science of resuscitation. Research in cellular resuscitation, mitochondrial function, membrane permeability, ischemia, and reversal of cell death provides a unifying patho-
physiologic focus and opens up possibilities for extensive basic science exploration. Such research will be directly applicable to the emergency department and prehospital care and at the same time foster new opportunities for emergency physicians. We can complete more successfully for large research grants when basic science research is part of our general research effort. We can offer a basic science research track to interested and capable emergency physicians. We can offer a basic science research exposure to residents and fellows. Stressing the need for faculty development, Dr Glenn Hamilton writes, "We will always be in 'second-class citizen' mindset in relation to our peers in academic medicine until there are deans of medical schools with emergency medicine backgrounds; until there are endowed professorships/chairs and research institutes in emergency medicine...,,2 Clearly, the development of basic science research to augment our overall research program can help us to strengthen areas where we now lag behind other specialties. Again, I thank Dr Schwab for his response and welcome the comments of others. It is only through the exchange of diverse opinions and differing viewpoints that we will stimulate the development and maturation of our specialty. As we seek a fuller definition of the field and a vision for the future, we are just beginning to explore the elephant. Lance B Becket, MD Division of Emergency Medicine, Department of Medicine University of Chicago 1. GrayBK: The rise of emergencymedicine. EmergencyMedical Services 1982;11:39-41. 2. Hamilton GC: Faculty development in emergency medicine. Am 1 Emerg Med 1988;6:540-544.
Benefits of Early Defibrillation To the Editor." Olson and his associates are to be commended for sharing with us their experience with EMT-defibrillation in Wisconsin in their article, "EMT-Defibrillation: The Wisconsin Experience" [August 1989;18:806-811]. It is only through publication of such continued experience that we will be able to define clearly the objective benefits of early defibrillation in a variety of prehospital environments. There are several points in this paper that we believe need to be underscored and understood in an attempt to determine the benefit of early defibrillation from this experience in Wisconsin. The limitations imposed by using a historical control group and a two-year retrospective review of that patient population must be understood. Although survival from ventricular fibrillation (VF) in communities of less than 6,000 people was 9% (six of 67), survival from all communities of less than 15,000 was 7% 172/613
(11 of 157). This was less than half the survival rate from VF in communities of more than 15,000 people. It is important to emphasize that most truly "rural" communities should not realistically expect survival figures to compare favorably with those from larger communities. There were 33 survivors among the 304 patients with VF, but ten of these 33 survivors failed to respond to prehospital defibrillatory shocks and were only resuscitated in the emergency department. It cannot be assumed that these ten patients benefitted in any way from prehospital defibrillation. One must then conclude that early defibrillation appeared to contribute to survival in 23 of 304 patients with VF (7.5%). Eleven of the survivors of prehospital VF had experienced an EMT-witnessed arrest. Obviously this quite high incidence of EMT-witnessed arrest (26 of 304 patients with VF) with immediate availability of defibrillation,
Annals of Emergency Medicine
19:5 May 1990
weighed heavily in the survival from VF. We do not known how many of the 23 survivors who benefitted from prehospital defibrillation were in this EMT-witnessed group. Obviously those patients who experienced an EMTwitnessed arrest, were defibrillated immediately, and regained a spontaneous circulation were the direct beneficiaries of this intervention. At the same time, such patients comprise a rather select group among those with out-ofhospital VF, in this study a somewhat surprisingly large 8.5% of those with VF. Ten survivors experienced impaired cerebral performance. EKen if~ this includes all three patients with electromechanical dissociation, there still remain seven "survivors" of VF with cerebral impairment. Whether patients with neurologic impairment after cardiorespiratory arrest and resuscitation should be considered "survivors" is certainly open to serious question.
We believe these observations on this experience must be taken into account in an attempt to define the presumed benefits of early defibrillation conferred on patients in this published experience. We have been, and remain, advocates of the development and implementation of early defibrillation programs, but we believe it is mandatory to scrutinize available data very carefully in quantitating the benefits of this treatment in a variety of prehospital environments.
Roger D White, MD Department of Anesthesiology Larry F Vukov, MD Department of Medicine Mayo Medical School and Mayo Clinic Rochester, Minnesota
D a t a C o l l e c t i o n & O b s e r v e r Bias To the Editor: Drs Jones, Nesper, and Alcouloumre reported the results of a prospective examination of prehospital intravenous line placement in "Prehospital Intravenous Line Placement: A Prospective Study" [March 1989;18:244246]. Although the authors did not subject their data to statistical analysis, they did report rates. It is our conclusion that an incorrect denominator was used to determine the IV line start success rate. The denominator used was identified in the following excerpt from the paper: "All data forms that were returned and that included an IV line attempt (except those performed by a paramedic trainee) were entered into the study." The total number of IV line attempts, not the number of data forms returned, by the observed paramedic units during the period of the study would have been the correct denominator. One can imagine a worst-case scenario in ~which wellmeaning but biased observers return only data forms for IV line attempts that proceed quickly and successfully.
Roland W Petri, MD Stanford University Stanford, California Robert Wears, MD University of Florida Jacksonville In Reply: We appreciate the comments by Drs Petri and Wears in regard to our study. The language used in the methods section may have misled them to make an erroneous in-
ference. Because the data forms included some information that was obtained by observers in advance of the IV attempt (age, chief complaint, time of arrival, initial vital signs), many data forms were initiated on patients who ultimately did not have an IV line attempted. Because the true denominator was the number of IV attempts, only the patients on whom an IV line was attempted were included in the study. Alternately, we could have stated that "all data forms that were returned that did not include an IV attempt were not entered into the study." Although any unblinded observational study like ours is potentially subject to observer bias, we disagree with their inference that it did occur. Paramedics were the only personnel starting the IV lines in the study, and none of our observers were paramedics. Most of the observers were medical students who were unaware of the controversy surrounding prehospital line placement, and they were not routinely informed of the underlying purpose of the study. Finally, given their distinct observer status, we believe it is unlikely that observers gained any individual benefit by biasing the outcome.
Stephen E Jones, MD LAC/USC Medical Center Los Angeles, California Timothy P Nesper, MD Riverside General Hospital~University Medical Center Riverside, California Eric Alcouloumre, MD Hoag Memorial Hospital Newport Beach, California
C o s t - E f f e c t i v e n e s s : A s s e r t e d , Not S h o w n To the Editor: Cwinn and colleagues asserted cost-effectiveness for their approach to providing emergency medical services at 19:5 May 1990
Denver's Stapleton International Airport in their article, "Prehospital Care at a Major International Airport" [Octo-
Annals of Emergency Medicine
614/173
Much like the fable of three blind men with completely different descriptions of the same elephant, each viewpoint may be completely accurate, while the larger truth involves the merger of multiple descriptions. I described a basic science foundation in resuscitation as a unifying p a t h o p h y s i o l o g i c focus for emergency medicine. Dr Schwab prefers to focus on cost-effective, high-quality health care delivery for patients. Others have alternatively suggested that we should focus on the subtlety and variety of disease presentation or on the range of required diagnostic skills. My view of the genesis of emergency medicine in the treatment of shock and acute hypotension is shared by others. Dr B Ken Gray, past president of the American College of Emergency Physicians, writes, "We are all familiar with the origins of emergency medicine. The battlefield medical systems of Korea and Vietnam taught us more about the practice than any system prior to that time. Triage systems, quick stabilization methods, and emergency surgery procedures were employed to save the lives of soldiers injured in battle. 'q The message of my editorial, however, was not that resuscitation should become the single focus of emergency medicine but that we now need to emphasize and develop basic science research in order to augment existing patient care, teaching, and clinical research. Obviously, research in resuscitation should not exclude all other research, nor should clinical research be seen as less important or valuable for our future than basic science research. But let us be clear: there is currently almost no basic science research within emergency medicine. This is to be expected in an emerging specialty, but to assure our growth and maturation it is now crucial for us to establish the link between clinical resuscitation and the basic science of resuscitation. Research in cellular resuscitation, mitochondrial function, membrane permeability, ischemia, and reversal of cell death provides a unifying patho-
physiologic focus and opens up possibilities for extensive basic science exploration. Such research will be directly applicable to the emergency department and prehospital care and at the same time foster new opportunities for emergency physicians. We can complete more successfully for large research grants when basic science research is part of our general research effort. We can offer a basic science research track to interested and capable emergency physicians. We can offer a basic science research exposure to residents and fellows. Stressing the need for faculty development, Dr Glenn Hamilton writes, "We will always be in 'second-class citizen' mindset in relation to our peers in academic medicine until there are deans of medical schools with emergency medicine backgrounds; until there are endowed professorships/chairs and research institutes in emergency medicine...,,2 Clearly, the development of basic science research to augment our overall research program can help us to strengthen areas where we now lag behind other specialties. Again, I thank Dr Schwab for his response and welcome the comments of others. It is only through the exchange of diverse opinions and differing viewpoints that we will stimulate the development and maturation of our specialty. As we seek a fuller definition of the field and a vision for the future, we are just beginning to explore the elephant. Lance B Becket, MD Division of Emergency Medicine, Department of Medicine University of Chicago 1. GrayBK: The rise of emergencymedicine. EmergencyMedical Services 1982;11:39-41. 2. Hamilton GC: Faculty development in emergency medicine. Am 1 Emerg Med 1988;6:540-544.
Benefits of Early Defibrillation To the Editor." Olson and his associates are to be commended for sharing with us their experience with EMT-defibrillation in Wisconsin in their article, "EMT-Defibrillation: The Wisconsin Experience" [August 1989;18:806-811]. It is only through publication of such continued experience that we will be able to define clearly the objective benefits of early defibrillation in a variety of prehospital environments. There are several points in this paper that we believe need to be underscored and understood in an attempt to determine the benefit of early defibrillation from this experience in Wisconsin. The limitations imposed by using a historical control group and a two-year retrospective review of that patient population must be understood. Although survival from ventricular fibrillation (VF) in communities of less than 6,000 people was 9% (six of 67), survival from all communities of less than 15,000 was 7% 172/613
(11 of 157). This was less than half the survival rate from VF in communities of more than 15,000 people. It is important to emphasize that most truly "rural" communities should not realistically expect survival figures to compare favorably with those from larger communities. There were 33 survivors among the 304 patients with VF, but ten of these 33 survivors failed to respond to prehospital defibrillatory shocks and were only resuscitated in the emergency department. It cannot be assumed that these ten patients benefitted in any way from prehospital defibrillation. One must then conclude that early defibrillation appeared to contribute to survival in 23 of 304 patients with VF (7.5%). Eleven of the survivors of prehospital VF had experienced an EMT-witnessed arrest. Obviously this quite high incidence of EMT-witnessed arrest (26 of 304 patients with VF) with immediate availability of defibrillation,
Annals of Emergency Medicine
19:5 May 1990
weighed heavily in the survival from VF. We do not known how many of the 23 survivors who benefitted from prehospital defibrillation were in this EMT-witnessed group. Obviously those patients who experienced an EMTwitnessed arrest, were defibrillated immediately, and regained a spontaneous circulation were the direct beneficiaries of this intervention. At the same time, such patients comprise a rather select group among those with out-ofhospital VF, in this study a somewhat surprisingly large 8.5% of those with VF. Ten survivors experienced impaired cerebral performance. EKen if~ this includes all three patients with electromechanical dissociation, there still remain seven "survivors" of VF with cerebral impairment. Whether patients with neurologic impairment after cardiorespiratory arrest and resuscitation should be considered "survivors" is certainly open to serious question.
We believe these observations on this experience must be taken into account in an attempt to define the presumed benefits of early defibrillation conferred on patients in this published experience. We have been, and remain, advocates of the development and implementation of early defibrillation programs, but we believe it is mandatory to scrutinize available data very carefully in quantitating the benefits of this treatment in a variety of prehospital environments.
Roger D White, MD Department of Anesthesiology Larry F Vukov, MD Department of Medicine Mayo Medical School and Mayo Clinic Rochester, Minnesota
D a t a C o l l e c t i o n & O b s e r v e r Bias To the Editor: Drs Jones, Nesper, and Alcouloumre reported the results of a prospective examination of prehospital intravenous line placement in "Prehospital Intravenous Line Placement: A Prospective Study" [March 1989;18:244246]. Although the authors did not subject their data to statistical analysis, they did report rates. It is our conclusion that an incorrect denominator was used to determine the IV line start success rate. The denominator used was identified in the following excerpt from the paper: "All data forms that were returned and that included an IV line attempt (except those performed by a paramedic trainee) were entered into the study." The total number of IV line attempts, not the number of data forms returned, by the observed paramedic units during the period of the study would have been the correct denominator. One can imagine a worst-case scenario in ~which wellmeaning but biased observers return only data forms for IV line attempts that proceed quickly and successfully.
Roland W Petri, MD Stanford University Stanford, California Robert Wears, MD University of Florida Jacksonville In Reply: We appreciate the comments by Drs Petri and Wears in regard to our study. The language used in the methods section may have misled them to make an erroneous in-
ference. Because the data forms included some information that was obtained by observers in advance of the IV attempt (age, chief complaint, time of arrival, initial vital signs), many data forms were initiated on patients who ultimately did not have an IV line attempted. Because the true denominator was the number of IV attempts, only the patients on whom an IV line was attempted were included in the study. Alternately, we could have stated that "all data forms that were returned that did not include an IV attempt were not entered into the study." Although any unblinded observational study like ours is potentially subject to observer bias, we disagree with their inference that it did occur. Paramedics were the only personnel starting the IV lines in the study, and none of our observers were paramedics. Most of the observers were medical students who were unaware of the controversy surrounding prehospital line placement, and they were not routinely informed of the underlying purpose of the study. Finally, given their distinct observer status, we believe it is unlikely that observers gained any individual benefit by biasing the outcome.
Stephen E Jones, MD LAC/USC Medical Center Los Angeles, California Timothy P Nesper, MD Riverside General Hospital~University Medical Center Riverside, California Eric Alcouloumre, MD Hoag Memorial Hospital Newport Beach, California
C o s t - E f f e c t i v e n e s s : A s s e r t e d , Not S h o w n To the Editor: Cwinn and colleagues asserted cost-effectiveness for their approach to providing emergency medical services at 19:5 May 1990
Denver's Stapleton International Airport in their article, "Prehospital Care at a Major International Airport" [Octo-
Annals of Emergency Medicine
614/173
