Comparison of kinetic changes during helicopter medical evacuations: civilian versus military flights

Abstract

BackgroundHelicopter evacuation is crucial for providing medical care to casualties. Previous civilian studies have demonstrated that air transport can enhance survival rates compared with ground transport. However, there has been limited research on specific accelerations during helicopter flights, particularly in military flights. This study aims to analyse and compare the accelerations endured during civilian and military helicopter evacuations.MethodsAccelerations were recorded during evacuation flights from the site of injury to the first medical responders in civilian helicopter EC135 T1, and military Puma SA.330 and Caiman NH90 TTH helicopters. The research investigated global acceleration and compared acceleration distributions along the vertical, lateral and longitudinal axes. A specific comparative study of the take-off phases was also performed.ResultsThe analysis showed that vertical loads caused the most extreme accelerations for all types of helicopter but these extreme accelerations were rare and lasted for less than 1 s. Military flights show similar acceleration intensities to civilian flights, but accelerations are higher during short periods of the take-off phase.ConclusionsThe findings suggest that helicopter evacuations during military operations are as safe as civilian evacuations and highlight the importance of patient positioning in the aircraft. However, further research should investigate the haemodynamic response to accelerations experienced during actual evacuation flights.