Is decision making in hypoxia affected by pre-acclimatisation? A randomized controlled trial

Abstract

Background Decision making is impaired in hypoxic environments, which may have serious or even lethal consequences for mountaineers. An acclimatisation period prior to high altitude exposures may help to overcome adverse effects of hypoxia. Thus, we investigated possible effects of short-term pre-acclimatisation on decision making in hypoxia. Methods In a randomized controlled study design, 52 healthy participants were allocated to a hypoxia group (HG: short-term pre-acclimatization by the use of intermittent hypoxia 7 x 1 hour at FiO2 = 12.6%, equivalent to 4500 m) or a control group (CG: sham pre-acclimatization 7 x 1 hour at FiO2 = 20.9%, equivalent to 600 m). The number of risky decisions was assessed using the Game of Dice Task at four time points during a 12-hours stay in hypoxia (FiO2 = 12.6%). Findings 42 (HG: 27, CG: 25) participants completed the study. The number of risky decisions was significantly (p = .048 as determined by 4x2 ANCOVA) reduced in the hypoxia group compared to the control group, partial η² = 0.11, when the age-effect on decision making was controlled. Self-reported positive affective valence prior to decision making was negatively related to the number of risky decisions, r < -.38. Discussion Short-term pre-acclimatization might positively influence decision making in hypoxia and might be considered as a risk-reducing preparation method prior to exposures to hypoxic environments. Positive affective state seems to have a medium-sized protective effect against risky decision making.