飞行员7000 m高空缺氧耐力影响因素Cox比例风险模型分析:回顾性队列研究

Cox proportional hazards model analysis of influencing factors of hypoxia endurance for pilots at 7000 m altitude:a retrospective cohort study

目的 通过收集整理在空军特色医学中心进行急性缺氧耐力检查的飞行员的相关数据,分析探讨可能与飞行员缺氧耐力相关的影响因素。方法 回顾性分析近5年航空生理训练的男性飞行员414人,应用多因素Cox比例风险模型分析急性缺氧耐力与其相关影响因素之间的关系。结果 414名飞行员均完成缺氧耐力检查,总体平均缺氧耐受时间为325.1 s(95%CI:320.1~330.1),缺氧耐受时间大于360s的占56%,180~360s的占44%,2组飞行员血氧饱和度降至70%的生存时间有显著差异(HR=3.890,95%CI:3.049~4.964,P<0.001);多因素Cox比例风险模型分析结果显示,吸烟>0~5年者较不吸烟者对缺氧耐受时间有统计学差异(HR=0.577,95%CI:0.361~0.923,P=0.022);5 500 m 1 min血氧对缺氧耐受时间的影响有统计学差异(HR=0.922,95%CI:0.863~0.985,P=0.017),其他变量对缺氧耐受时间的影响差异无统计学意义(P>0.05)。结论 通过飞行员急性缺氧耐力相关影响因素的分析,为制定提高飞行员缺氧耐力的可行性措施提供依据。

Objective To analyze the influencing factors of hypoxic endurance among pilots.Methods The clinical data of 414 male pilots who underwent aviation physiology training was retrospectively analyzed.The multivariate Cox proportional hazards model was used to analyze the correlations between acute hypoxia tolerance and influencing factors.Results Four hundred and fourteen pilots completed the hypoxia tolerance test and the average time of hypoxia tolerance was 325.1 s(95%CI:320.1 to 330.1).Those with a hypoxia tolerance time above 360 s accounted for 56%,compared with 44%for those whose hypoxia tolerance time ranged from 180 s to 360 s.There was significant difference in the survival time between the two groups of pilots when oxygen saturation dropped to 70%(HR=3.890,95%CI:3.049~4.964,P<0.001).The multivariate Cox proportional hazards model analysis showed that there was statistically significant difference in hypoxia tolerance time between smokers(0<X≤5 years)and non-smokers(HR=0.577,95%CI:0.361 to 0.923,P=0.022).SpO_(2)at 5500 m 1 min made a huge difference to hypoxia tolerance time(HR=0.922,95%CI:0.863 to 0.985,P=0.017)unlike other variables(P>0.05).Conclusion Through the analysis of the influencing factors of pilots'acute hypoxia tolerance,it provided the basis for formulating feasible measures to improve pilots'acute hypoxia tolerance.