G-LOC recovery with and without G-suit inflation.

During acceleration (+Gz) training in the human centrifuge, the anti-G suit (AGS) is usually deflated as acceleration decreases upon termination of the exposure, regardless of the reason for termination, including +Gz-induced loss of consciousness (G-LOC). This is when the trainee most needs the support provided by the AGS. A method to reduce the time of incapacitation resulting from G-LOC was evaluated. The standard CSU15-P suit worn by 30 aircrew while undergoing +Gz tolerance training was inflated to 10 psi immediately upon G-LOC (GS group). Incapacitation times and flailing activity were recorded and compared with 51 aircrew whose AGS was not abruptly inflated upon G-LOC (NGS group). Absolute incapacitation was significantly different between both groups (p = 0.024). The GS group exhibited flailing behavior for a longer period of time during relative incapacitation than the NGS group (p = 0.0003). Total incapacitation remained unaffected. A brief period of confusion occasionally accompanied by mimic or myoclonic convulsions was observed more often in the GS group. Inflation of the AGS upon G-LOC seems to reduce absolute incapacitation by approximately 2 s, thereby causing the trainee to be aware of his environment and G-LOC more quickly, even though his motor function has not yet been fully restored.