Operational requirements may dictate the need for unacclimatized individuals to rapidly ascend over the course of just a few hours to high altitude. A combination of acetazolamide and/or dexamethasone to decrease the risk of HAI and allow the service member to perform better physically and mentally is recommended. Several prophylaxis protocols for this situation have been studied both in chamber and field settings.

Studies utilizing the protocols that include dexamethasone have been of short duration, usually less than 48 hours. Therefore we recommend when utilizing rapid ascent protocols that include dexamethasone the individuals should complete the mission and return to lower elevation in 48 hours or less. If dexamethasone is discontinued while individuals are at these altitudes AMS symptoms may occur.51-55