Activation intervals for a helicopter emergency medical service in Japan

Abstract

Introduction: Prehospital time is crucial for treating acute disease; therefore, it is important to activate helicopter emergency medical services (HEMS) promptly. We investigated the differences in the activation intervals (the time elapsed from receiving the emergency call to the time of HEMS request) under various conditions to evaluate the current status of HEMS-related prehospital triage in Japan.

Methods: We retrospectively investigated activation intervals under exogenous (trauma, n = 553; intoxication, n = 56; and burns, n = 32) and endogenous conditions (acute coronary syndrome [ACS], n = 47; and stroke, n = 173) between January 31, 2008, and January 31, 2012, by reviewing flight records.

Results: Activation intervals were trauma (14.3 ± 11.5 min), intoxication (10.3 ± 8.6 min), burns (15.0 ± 13.1 min), ACS (17.9 ± 14.6 min), and stroke (19.1 ± 13.1 min). One-way analysis of variance showed a significant difference between exogenous and endogenous groups (P < .001). Post-hoc analysis using Tukey's honestly significant difference test showed significant differences between ACS and intoxication (P < .05), stroke and intoxication (P < .001), and stroke and trauma (P < .001).

Conclusions: Endogenous conditions had longer activation intervals, which may reflect a lack of mechanisms assessing their severity. We are considering developing new triage criteria for dispatchers.