Abstract & Commentary
Source: Bochicchio GV, et al. Endotracheal intubation in the field does not improve outcome in trauma patients who present without an acutely lethal brain injury. J Trauma Inj Infect Crit Care 2003;54:307-311.
Recent studies have questioned the value of prehospital intubation, demonstrating equivalent or better outcomes in patients receiving bag-valve-mask ventilation until intubation upon arrival at the hospital. Most of these studies were retrospective, with the exception of a recent large, prospective, randomized trial that did not demonstrate any increase in survival among children intubated in the out-of hospital setting.1
This study prospectively evaluated whether prehospital intubation improved outcome among adult patients with non-lethal traumatic brain injury. One hundred ninety-one consecutive adult trauma patients over one year at Maryland Shock Trauma center were included if they had non-lethal (death within 48 hours) traumatic brain injury, Glasgow Coma Scale score (GCS) of 8 or below, and head abbreviated injury scale (HAIS) score of 3 or higher. Patients were excluded if death occurred within 48 hours or if they were kept alive for transplant purposes; failed field intubation or had greater than two attempts in the field; had prolonged field extrication times; or if they were transferred from an outside institution. Patients were stratified by whether they were intubated in the field or the trauma center. Major outcomes measured were death, incidence of pneumonia, hospital length of stay, intensive care unit (ICU) length of stay, and ventilator days.
During the study, 41% of patients were intubated in the field and 59% were intubated immediately at admission by a dedicated trauma anesthesiologist. Ninety-two percent of the patients sustained blunt trauma, and approximately two-thirds of patients arrived by air transport. There were no significant differences between the two groups in terms of age, injury severity score (ISS), GCS, and HAIS. There was no significant difference in frequency or distribution of non-cranial operations between the two groups. However, a significant increase in dispatch-to-arrival time was noted in the field intubation group.
Patients intubated in the field had significantly longer ICU and hospital lengths of stay. Also, field-intubated patients had more mean ventilator days (14.7 vs 10.4) and a greater incidence of pneumonia (49% vs 32%). The mortality rate of patients intubated in the prehospital setting also was greater (23% vs 14%, p = 0.05). This yields a relative risk of 1.53 for the development of pneumonia and a relative risk of 1.85 for death in the field-intubated group when compared to the hospital-intubated group. Patients intubated in the field also were more likely to have died due to respiratory related complications (61% vs 29%).
The authors conclude that patients with acute nonlethal traumatic brain injury have greater morbidity and mortality when intubated in the prehospital setting. They concede that there may be a subset of patients who would benefit from prehospital airway management, and that a large, prospective, randomized trial is necessary to determine which, if any, patients should be intubated in the field.
Commentary by Jacob W. Ufberg, MD
This paper adds to a small but growing body of data that does not support field intubation under usual circumstances (reasonable transport times and distances). It is unclear why patients intubated in the field do worse, but I would speculate that there is some relation to increased scene and transport times and perhaps an increase in the incidence of aspiration (as evidenced by more pneumonia and more respiratory deaths) among patients intubated in the field.
It is hard to accept this paper at face value. When field vs. hospital intubation is not randomized, we must assume that there was a reason why certain patients were, or were not, intubated in the field despite the similarities in ISS and HAIS (imperfect scoring systems).
Perhaps these patients appeared to be more critically ill and did worse due to some factor that escaped the authors’ data analysis. However, the results of this study are quite intriguing, and further display the need for a large, randomized, prospective, outcomes-based look at the value of out-of-hospital intubation.
Dr. Ufberg, Assistant Professor of Emergency Medicine, Assistant Residency Director, Department of Emergency Medicine, Temple University School of Medicine, Philadelphia, PA, is on the Editorial Board of Emergency Medicine Alert.
1. Gausche M, et al. Effect of out-of-hospital pediatric endotracheal intubation on survival and neurological outcome: A controlled clinical trial. JAMA 2000;283:783-790.