Aerosp Med Hum Perform. 2023 Jan 1;94(1):3-10. doi: 10.3357/AMHP.6123.2023.
A flight trial was conducted to determine whether breathing 60% oxygen during high performance flight maneuvers using contemporary pilot flight equipment induces atelectasis and to explore whether cabin altitude had any influence on the extent of atelectasis identified. On 2 separate days, 14 male aircrew flew as passengers at High [14,500-18,000 ft (4420-5486 m)] and Low [4000-6000 ft (1219-1829 m)] cabin pressure altitude in a Hawk T Mk1 aircraft breathing 60% oxygen. Sorties comprised 16 maneuvers at +5 G, each sustained for 30 s. Lung volumes (spirometry), basal lung volume (electrical impedance tomography, EIT), and peripheral oxygen saturation during transition from hyperoxia to hypoxia (pulmonary shunt fraction) were measured in the cockpit immediately before (Pre) and after (Post) flight. Forced inspiratory vital capacity (FIVC) was significantly lower Postflight after High (-0.24 L) and Low (-0.38 L) sorties, but recovered to Preflight values by the fourth repeat (FIVC4). EIT-derived measures of FIVC decreased after High (-3.3%) and Low (-4.4%) sorties but did not recover to baseline by FIVC4. FIVC reductions were attributable to decreased inspiratory capacity. So₂ was lower Postflight than Preflight in High and Low sorties. Breathing 60% oxygen during flight results in a 3.8-4.9% reduction in lung volume associated with a small decrease in blood oxygenation and an estimated pulmonary shunt of up to 5.7%. EIT measures suggest persisting airway closure despite repeated FIVC maneuvers. There was no meaningful influence of cabin pressure altitude. The operational consequence of the observed changes is likely to be small.
一项飞行试验旨在确定在使用现代飞行员飞行设备进行高性能飞行机动时呼吸 60%氧气是否会导致肺不张，并探讨舱内高度对所确定的肺不张程度是否有任何影响。在 2 个不同的日子里，14 名男性机组人员分别以高舱压[14500-18000 英尺（4420-5486 米）]和低舱压[4000-6000 英尺（1219-1829 米）]作为乘客在一架 Hawk T Mk1 飞机中呼吸 60%氧气。飞行任务包括 16 次+5G 的机动，每次持续 30 秒。在飞行前（Pre）和飞行后（Post），在驾驶舱中测量肺活量（肺活量测定法）、基础肺体积（电阻抗断层扫描，EIT）和从高氧到低氧过渡期间的外周血氧饱和度（肺分流分数）。在高舱压（-0.24L）和低舱压（-0.38L）飞行任务后，用力吸气肺活量（FIVC）在飞行后明显降低，但在第四次重复（FIVC4）时恢复到飞行前的值。EIT 衍生的 FIVC 测量值在高舱压（-3.3%）和低舱压（-4.4%）飞行任务后降低，但在 FIVC4 时未恢复到基线。FIVC 的减少归因于吸气能力的降低。在高舱压和低舱压飞行任务中，So₂在飞行后比飞行前低。在飞行过程中呼吸 60%氧气会导致肺容量减少 3.8-4.9%，同时血氧饱和度略有下降，估计肺分流高达 5.7%。EIT 测量表明，尽管反复进行 FIVC 操作，但气道仍持续关闭。舱内压力高度没有明显影响。观察到的变化的操作后果可能很小。
