Effectiveness of a "doctor-helicopter" system in Japan.

BACKGROUND In Japan, helicopters have rarely been used for emergency medical services. The use of helicopters not only ensures rapid evacuation but may also serve to provide emergency management to patients with life-threatening injuries in the prehospital setting. OBJECTIVES To evaluate a Japanese helicopter-based emergency medical system including an onboard physician, particularly in terms of probability of survival. METHODS We conducted a retrospective review of trauma victims, and calculated two estimates of PS--at the scene and on arrival at the emergency department--based on patient age, Injury Severity Score, and Revised Trauma Score. RESULTS We identified trauma victims who had an ISS above 15 and were transported from the scene by helicopter. Excluding cardiopulmonary arrest at the scene, 151 cases were studied. Thirty-two patients had hemodynamic instability with systolic blood pressures below 90 mmHg, caused by hemorrhagic shock (29 cases) or obstructive shock (3 cases). Their PS values were 0.56 +/- 0.38 in the prehospital setting and 0.65 +/- 0.38 on arrival at the ED, representing a significant difference (P = 0.0003). Twenty-four of these patients survived, reflecting successful resuscitation during prehospital and ED management. CONCLUSIONS A doctor-helicopter system was shown to improve probability of survival for life-threatening trauma in the Japanese emergency medical system.