Webb James T, Krock Larry P, Gernhardt Michael L
NASA Johnson Space Center, Houston, TX, USA.
Aviat Space Environ Med. 2010 Nov;81(11):987-92. doi: 10.3357/asem.2787.2010.
The existence of a general influence of exercise on the incidence of decompression sickness (DCS) has been known for more than a half-century. However, quantification of the effect has not been done for several reasons, including isolation of exercise as the only variable. The DCS database at Brooks City-Base, TX, contains detailed physiologic information on over 3000 altitude exposures. The purpose of this study was to measure Vo2 during the activities performed during those exposures to retrospectively determine if Vo2, a quantifiable index of exercise intensity, was related to the level of reported DCS.
Ground-level activity was designed to duplicate the standardized activity during the altitude exposures. Breath-by-breath Vo2 was determined for each activity using a COSMED metabolic measurement system. Comparison of the Vo2 during four levels of activity performed under otherwise comparable conditions allowed a determination of correlation between Vo2 and DCS risk observed during the altitude exposures.
Four previous altitude exposure profiles at 8992 m to 9144 m (29,500 to 30,000 ft; 231 to 226 mmHg) for 4 h following a 1-h prebreathe resulted in 38-86% DCS. This study provided the Vo2 of activities during those studies. The correlation between DCS incidence and the highest 1-min Vo2 of activity was 0.89.
The highest 1-min Vo2 showed a high correlation with level of DCS risk. Future exposures involving lower levels of activity could provide data that would allow improvement in modeling of DCS risk.
运动对减压病（DCS）发病率的总体影响已为人所知达半个多世纪。然而，由于多种原因，包括将运动作为唯一变量进行隔离，尚未对这种影响进行量化。德克萨斯州布鲁克斯市基地的DCS数据库包含了超过3000次高空暴露的详细生理信息。本研究的目的是测量这些暴露期间所进行活动中的摄氧量（Vo2），以回顾性地确定Vo2（运动强度的可量化指标）是否与报告的DCS水平相关。
地面活动旨在复制高空暴露期间的标准化活动。使用COSMED代谢测量系统确定每次活动的逐次呼吸Vo2。在其他条件相当的情况下，对四个活动水平下的Vo2进行比较，从而确定Vo2与高空暴露期间观察到的DCS风险之间的相关性。
在1小时预呼吸后，对海拔8992米至9144米（29500至30000英尺；231至226毫米汞柱）进行4小时的四次先前高空暴露记录显示，DCS发病率为38%至86%。本研究提供了这些研究期间活动的Vo2。DCS发病率与活动中最高1分钟Vo2之间的相关性为0.89。
最高1分钟Vo2与DCS风险水平显示出高度相关性。未来涉及较低活动水平的暴露可能会提供数据，从而改进DCS风险模型。
