Sullivent EE, Faul M, Wald MM. Reduced mortality in injured adults transported by helicopter emergency medical services. Prehosp Emerg Care, Apr 27, 2011 [e-pub ahead of print].
Background—Some studies have shown improved outcomes with helicopter emergency medical services (HEMS) transport, while others have not. Safety concerns and cost have prompted reevaluation of the widespread use of HEMS. Objective—To determine whether the mode of transport of trauma patients affects mortality. Methods—Data for 56,744 injured adults aged greater than or equal to 18 years transported to 62 U.S. trauma centers by helicopter or ground ambulance were obtained from the National Sample Program of the 2007 National Trauma Data Bank. In-hospital mortality was calculated for different demographic and injury severity groups. Adjusted odds ratios (AOR) were produced by utilizing a logistic regression model measuring the association of mortality and type of transport, controlling for age, gender and injury severity (Injury Severity Score [ISS] and Revised Trauma Score [RTS]).
Results—The odds of death were 39% lower in those transported by HEMS compared with those transported by ground. Among those aged greater than or equal to 55 years, the odds of death were not significantly different. Among all transports, male patients had a higher odds of death (AOR = 1.23) than female patients. The odds of death increased with each year of age and each unit of ISS, and decreased with each unit of RTS. Conclusion—The use of HEMS for the transport of adult trauma patients was associated with reduced mortality for patients aged 18–54 years. In this study, HEMS did not improve mortality in adults aged greater than or equal to 55 years. Identification of additional variables in the selection of those patients who will benefit from HEMS transport is expected to enhance this reduction in mortality.
There are differing opinions on the appropriateness of HEMS response and transportation. This study from the Centers for Disease Control and Prevention concludes that trauma patients under the age of 55 were 39% less likely to die of their injuries if transported by HEMS. The reasons are not clear. Shortening the time to definitive treatment, especially in areas with sparse ground resources or long distances to a regional trauma center, is one benefit; equipment and crew expertise is another. Future studies will better answer this question.
These benefits must also be weighed against safety and cost concerns and be put in context of the local EMS system. Abundant ground resources with short transport times would not be circumstances where HEMS would be expected to be helpful. But for the seriously injured patient not close to a trauma center, HEMS appears to have a role in improving patient care. EMS systems should evaluate their protocols with this in mind.
Angelo Salvucci, Jr., MD, FACEP, is medical director for the Santa Barbara County and Ventura County (CA) EMS agencies and a member of EMS World's editorial advisory board.