2013 Volume 24 Issue 1 Pages 12-18
Background: Many studies have commented on the usefulness of helicopter emergency medical services (HEMS) for the transportation of trauma patients. However, several studies have also noted that the majority of patients transported by HEMS to Level I trauma centers had minor injuries, and warned of inappropriate use of HEMS and the need for appropriate prehospital triage. In Japan, information about the injury severity of trauma patients transported by HEMS is lacking, and the appropriateness of field triage performed by HEMS is not clear. The purpose of this study was to investigate the validity of HEMS transportation in terms of the injury severity of trauma patients who were transported to our Emergency and Critical Care Medical Center (ECCMC) in Fukushima, Japan. Methods: We retrospectively evaluated all trauma patients who were brought to our ECCMC from the scene of an accident between March 1, 2009 and January 31, 2012. We compared Injury Severity Score (ISS), Revised Trauma Score (RTS), and probability of survival (Ps) as indicators of trauma severity, and emergency operation rate, intensive care unit (ICU) admission rate, and mechanical ventilation rate as indicators of specialized trauma care between patients transported by HEMS and those transported by ground ambulance (GA).
Results: We identified 450 trauma patients (324 males and 126 females, aged 51±24 years), of which 110 (24.4%) were transported by HEMS. The HEMS group had significantly more severe trauma than the GA group (ISS: 17.7±11.5 vs. 12.4±9.5, p<0.001; RTS: 6.8±1.8 vs. 7.4±1.1, p<0.01; Ps: 0.82±0.29 vs. 0.92±0.19, p<0.01, respectively), and needed significantly more specialized trauma care (emergency operation rate: 32.7% vs. 20.6%, p<0.01; ICU admission rate: 52.7% vs. 32.6%, p<0.001; mechanical ventilation rate: 41.8% vs. 17.6%, p<0.001, respectively).
Discussion: HEMS field triage by flight medical teams is almost ideal in terms of the injury severity of patients transported to our ECCMC. This triage is one of the great advantages of the service. Dispatchers should activate HEMS without hesitation if severe injury is suspected. Some over-triage by dispatchers is justified because flight medical teams provide important secondary triage, including further evaluation of trauma severity and choosing of the most appropriate hospital for treatment.
