Effect of Prehospital Endotracheal Intubation on Outcome

abstract & commentary

Source: Gausche M, et al. Effect of out-of-hospital pediatric endotracheal intubation on survival and neurological outcome. A controlled trial. JAMA 2000;283:783-790.

This prospective, controlled clinical trial compared prehospital pediatric endotracheal intubation (ETI) with bag-valve-mask ventilation (BVM) in a large urban-suburban community (Los Angeles and Orange counties in California). Pediatric patients (age 12 or younger or weight less than 40 kg) who required airway management in the field (for cardiopulmonary arrest, respiratory arrest or failure, airway obstruction, or other need for assisted ventilation) were assigned to either BVM or ETI based on alternating calendar days. Prior to enrolling patients, paramedics underwent six hours of pediatric airway management training, including skills testing for BVM and ETI on manikins.

Data were collected on patient demographics, illness, prehospital interventions, airway management, complications, hospital course, and patient outcome from data forms completed by paramedics and emergency department physicians, structured interviews with paramedics immediately after patient care, and retrospective review of prehospital and hospital records. Investigators compared survival and neurologic outcomes at discharge between BVM and ETI groups.

During the two-year study period, 830 consecutive patients were enrolled, of which 410 (49%) were assigned to BVM and 420 (51%) to ETI. There was no difference in survival to hospital discharge between the BVM and ETI groups (31% vs 26%, respectively). There was also no difference in the number of survivors with good neurologic outcomes between the groups (23% vs 20%, respectively, as defined by the Pediatric Cerebral Performance Category scale). While the ETI group had slightly longer field times, there was no difference in hospital or ICU lengths of stay.

Of the 410 patients assigned to BVM days, 391 received only BVM, nine received BVM after attempted ETI, and 10 actually underwent ETI. Of the 420 patients assigned to ETI days, 305 (73%) had ETI attempted, of which 177 (57%) were successfully intubated. The remaining 115 patients received only BVM. Based on actual treatment received, survival and neurologic outcome were actually worse in intubated patients. Complications were common and included esophageal intubation (2%), tube dislodgement (14%), mainstem bronchus intubation (18%), and incorrect tube size (24%).

Based on their findings, the investigators conclude that inclusion of pediatric ETI within the paramedic scope of practice does not improve survival or neurologic outcome for pediatric patients when compared to BVM alone.

Comment by Theodore C. Chan, MD, FACEP

This excellent, well-designed study is important for a number of reasons. First, it challenges the conventional wisdom that prehospital endotracheal intubation is safe, effective, and beneficial for pediatric patients. Second, this study uses clinically important outcome measures—survival and neurologic outcome—to assess efficacy. The need for outcomes research in emergency medical services (EMS) has long been debated in the literature, particularly as paramedic scope of practice has dramatically increased in many communities with little scientific evidence of clinical benefit.1

It is important to note that data were analyzed primarily on an intention-to-treat basis, comparing the inclusion and exclusion of pediatric ETI in paramedic scope of practice. Little more than half the patients on ETI days were in fact successfully intubated. Comparing actual treatment received creates a potential bias against ETI, as those with the least chance for survival were likely the easiest to intubate successfully.

The effort that went into this study cannot be overstated. This study involved more than 50 paramedic agencies, 100 health care institutions, and 3000 paramedics in two large counties. Despite the enormous resources directed at education, many paramedics never enrolled a patient in the study. The high ETI failure and complication rates may reflect a degradation in skills, casting doubt on the ability to perform this infrequent procedure effectively in the field.

Finally, it should be noted that the findings may not be applicable to all EMS jurisdictions. The median time from scene to hospital was six minutes. With such short transport, it would be difficult to show significant outcome benefit for many field interventions. Regions with longer transport times may have vastly different results.

Reference

1. Cone DC. Outcomes research and emergency medical services: The time has come. Acad Emerg Med 2000; 7:188-191.

25. Based on an intention-to-treat analysis, the study by Gausche et al on pediatric intubation in the prehospital setting found that:

a. intubation improved survival to hospital discharge compared to BVM.

b. BVM improved neurologic outcome for surviving patients compared to intubation.

c. survival and neurologic outcome were no different between the intubation and BVM groups.

d. the study was biased by the fact that BVM was more easily performed on nonsurvivors.