Management of Circadian Desynchrony (Jetlag and Shiftlag) in CF Air Operations

Abstract : In response to operational difficulties resulting from the effects of fatigue (secondary to jetlag and shiftlag) on performance of Air Force personnel, the Air Force funded a 4-year project to optimize CF ability to manipulate circadian rhythms forwards or backwards to counter jetlag and shiftlag. This report presents the highlights of that work and offers recommendation for exploitation of this new capability to sustain operational readiness. The project consisted of 7 studies. Four studies involved light treatment, 2 studies involved efficacy comparisons of 3 melatonin formulations to produce a phase advance and a phase delay and the final study involved a combination of melatonin and light treatment. We identified the best 2 of 4 light treatment devices, confirmed optimal melatonin doses and determined the correct treatment times with light and melatonin for circadian phase advance and phase delay. We can now develop circadian treatments using light and melatonin along with shifting sleep/wake times and avoidance of light at key times across a broad range of operational scenarios. We are therefore in a position to exploit our new circadian phase shifting capability to counter jetlag and shiftlag. Recommendations. 1. That the Director General Health Services acquire several different melatonin dose sizes and formulations for the CF formulary, along with light treatment devices for use at squadron/wing level ; 2. that the Air Force develop medical doctrine to guide Flight Surgeons in overseeing circadian interventions to improve/sustain operational readiness and 3. that the Air Force operational community develop specific directives to assist aircrew and groundcrew in dealing with jetlag and shiftlag based on current knowledge as detailed in this report.

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