Due to hardware malfunction on L-45, data were not obtained, and only two data sets were used for preflight means (L-30 and L-15). The Apollo atmosphere was 258 torr oxygen, but varied from 165 torr to 200 torr during Apollo-Soyuz docking and subsequent activities.
Further complications ensued following exposure to nitrogen tetroxide fumes during reentry. Therapy was administered by breathing 100% oxygen at 760 torr for 15 to 20 minutes aboard the recovery vessel. All crewmen complained of chest tightness, retrosternal burning sensation, inability to inhale deeply and nonproductive cough. Pulmonary function tests were conducted on each crewmember on R+0, and no significant changes were observed when compared to preflight means. However, ventilatory equivalent (VA/RV) showed a 30% increase, which indicated poor ventilation during residual volume (RV) determinations. Nitrogen tetroxide exposure was anticipated to cause significant pulmonary difficulty within the first 24 to 36 hours after landing. Thus, any physiological changes associated with space flight were probably concealed by responses to nitrogen tetroxide exposure.
Twenty-four hours later, symptoms worsened for all crewmen. Because of discomfort associated with deep inspiration and breath holding, satisfactory data could not be obtained on R+1 and R+2. Blood gas analysis indicated mild respiratory alkalosis with hyperventilation and hypoxia. The only significant finding, on R+2, was a decrease in the single-breath carbon monoxide diffusing capacity (DLCOSB). These findings agreed with the observed radiograph abnormalities that revealed the presence of diffuse nodular-type infiltrates throughout both lung fields. This decrease in DLCOSB persisted until testing on R+13. R+29 data showed pulmonary function parameters, including DLCOSB and repeat blood gas determinations (breathing room air and 100% oxygen), were within normal limits.
On R+0, Crewman A showed decreased RV, total lung capacity (TLC) and forced vital capacity (FVC), which remained below preflight values on all remaining tests. This indicated that nitrogen washout at the RV position did not start during postflight determinations. FVC, TLC and maximum expiratory flow rate (MEFR) were decreased on R+29. Crewman B demonstrated increased RV, closing volume (CV), and FVC on R+0. At R+29, the CV remained increased whereas FVC was slightly reduced relative to preflight. On R+0, Crewman C showed slightly reduced maximum midexpiratory flow rate (MMFR). R+29 increases were observed in VC and FVC.
In conclusion, the weightless environment appeared to have no significant impact on either respiratory mechanics or lung structure. Although, as reported by Tripler Army Hospital, R+1 data did show nitrogen tetroxide exposure caused pulmonary difficulty, which resulted in decreased pulmonary function. Overall, no disturbing decreases or significant changes, which could be attributed to space flight, were observed when compared to preflight means.
|Mission||Launch/Start Date||Landing/End Date||Duration|
|ASTP||07/15/1975||07/24/1975||9 days, 7.5 hours|