Lama Vibha N, Flaherty Kevin R, Toews Galen B, Colby Thomas V, Travis William D, Long Qi, Murray Susan, Kazerooni Ella A, Gross Barry H, Lynch Joseph P, Martinez Fernando J
Department of Radiology, University of Michigan Health System, University of Michigan School of Public Health, Ann Arbor, MI 48109-0360, USA.
Am J Respir Crit Care Med. 2003 Nov 1;168(9):1084-90. doi: 10.1164/rccm.200302-219OC. Epub 2003 Aug 13.
Exercise-induced hypoxia is an index of the severity of interstitial lung disease. We hypothesized that desaturation during a 6-minute walk test would predict mortality for patients with usual interstitial pneumonia (n = 83) and nonspecific interstitial pneumonia (n = 22). Consecutive patients with biopsy-proven disease performed a 6-minute walk test between January 1996 and December 2001. Desaturation was defined as a fall in oxygen saturation to 88% or less during the 6-minute walk test. Desaturation was common (44 of 83 usual interstitial pneumonia and 8 of 22 nonspecific interstitial pneumonia; chi square, p = 0.39). Patients with usual interstitial pneumonia or nonspecific interstitial pneumonia who desaturated had a significantly higher mortality than patients who did not desaturate (respective log-rank tests, p = 0.0018, p = 0.0089). In patients with usual interstitial pneumonia, the presence of desaturation was associated with an increased hazard of death (hazard ratio, 4.2; 95% confidence interval, 1.40, 12.56; p = 0.01) after adjusting for age, sex, smoking, baseline diffusion capacity for carbon monoxide, FVC, and resting saturation. We conclude that knowledge of desaturation during a 6-minute walk test adds prognostic information for patients with usual interstitial pneumonia and nonspecific interstitial pneumonia.
运动诱发的低氧血症是间质性肺疾病严重程度的一项指标。我们推测，6分钟步行试验期间的血氧饱和度下降可预测特发性间质性肺炎患者（n = 83）和非特异性间质性肺炎患者（n = 22）的死亡率。1996年1月至2001年12月期间，连续的经活检证实患有疾病的患者进行了6分钟步行试验。血氧饱和度下降定义为在6分钟步行试验期间血氧饱和度降至88%或更低。血氧饱和度下降很常见（83例特发性间质性肺炎患者中有44例，22例非特异性间质性肺炎患者中有8例；卡方检验，p = 0.39）。出现血氧饱和度下降的特发性间质性肺炎或非特异性间质性肺炎患者的死亡率显著高于未出现血氧饱和度下降的患者（各自的对数秩检验，p = 0.0018，p = 0.0089）。在特发性间质性肺炎患者中，在校正年龄、性别、吸烟、基线一氧化碳弥散量、用力肺活量和静息血氧饱和度后，血氧饱和度下降与死亡风险增加相关（风险比，4.2；95%置信区间，1.40, 12.56；p = 0.01）。我们得出结论，了解6分钟步行试验期间的血氧饱和度下降情况可为特发性间质性肺炎和非特异性间质性肺炎患者增加预后信息。
