Predictors of short-term survival after helicopter rescue.

The purpose of the present retrospective study was to identify easily obtainable predictors of short-term outcome for emergency victims treated by a physician-staffed helicopter emergency medical system (HEMS). The study was conducted at the HEMS unit 'Christophorus 1' based at Innsbruck, Austria. Outcomes for 2139 patients rescued in primary missions during a 3-year period from 1 January 1989 to 31 December 1991 were included in the study. The majority of missions were in response to sports accidents, although missions included a wide spectrum of emergencies. Data were obtained from the 'Christophorus 1' operation protocols and by written, personal, or telephone request from admitting hospitals. Eleven parameters selected from the HEMS flight logs were tested for their predictive value on survival following helicopter rescue. In a univariate analysis, the cause of the emergency, time at the scene, total duration of the emergency mission, patient age, patient gender, severity of the emergency using the National Advisory Committee of Aeronautics (NACA) scoring system, state of consciousness, respiratory status and patient circulatory status each had a statistically significant influence on survival up to 90 days following the emergency. Flight time to the scene and the original specialty of the additionally trained emergency physician had no significant influence on outcome. Multivariate analysis using the Cox proportional hazards model revealed that severity of the emergency by the seven-level NACA scale (P = 0.0001), initial respiratory status (P = 0.0001), time at the scene (P = 0.0108), patient age (P = 0.0047) and patient gender (P = 0.0477) were each independent predictors of short-term survival following physician-staffed helicopter rescue. We conclude that the parameters described above can be used in an initial predictive assessment by the flight physician and the admitting institution.