Dillard T A, Berg B W, Rajagopal K R, Dooley J W, Mehm W J
Walter Reed Army Medical Center, Washington, DC.
Ann Intern Med. 1989 Sep 1;111(5):362-7. doi: 10.7326/0003-4819-111-5-362.
To quantitate and identify determinants of the severity of hypoxemia during air travel in patients with chronic obstructive pulmonary disease.
Prospective study of physiologic variables before and during intervention.
Referral-based pulmonary disease clinic at a U.S. Army medical center.
Eighteen ambulatory retired servicemen (age 68 +/- 6 [SD] years) with severe chronic obstructive pulmonary disease (forced expiratory volume in the first second [FEV1] 31% +/- 10% of predicted).
Altitude simulation equivalent to 2438 meters (8000 feet) above sea level in a hypobaric chamber.
Radial artery catheter blood oxygen tension in the patients declined from a ground value (PaO2G) at sea level of 72.4 +/- 9 mm Hg to an altitude value (PaO2Alt) of 47.4 +/- 6 mm Hg after 45 minutes of steady state hypobaric exposure. The PaO2G correlated with PaO2Alt (r = 0.587; P less than 0.01). Multiple regression analysis revealed that the preflight FEV1 reduced the variability in PaO2Alt not explained by PaO2G in the equation: PaO2Alt = 0.453 [PaO2G] + 0.386 [FEV1% predicted] + 2.440 (r = 0.847; P less than 0.001). Residuals from two previously published formulas using PaO2G also correlated with FEV1 (r greater than or equal to 0.765; P less than 0.001).
Arterial blood oxygen tension declined to clinically significant levels in most patients during hypobaric exposure. When combined with the preflight arterial PO2 at ground level (PaO2G), the measurement of the preflight FEV1 improved prediction of PaO2 at altitude (PaO2Alt) in patients with severe chronic obstructive pulmonary disease.
对慢性阻塞性肺疾病患者航空旅行期间低氧血症的严重程度进行定量并确定其决定因素。
对干预前后生理变量进行前瞻性研究。
美国陆军医疗中心一家基于转诊的肺病诊所。
18名患有严重慢性阻塞性肺疾病（第一秒用力呼气量[FEV1]为预测值的31%±10%）的门诊退休军人（年龄68±6[标准差]岁）。
在低压舱内模拟相当于海拔2438米（8000英尺）的高度。
在稳定的低压暴露45分钟后，患者桡动脉导管血氧分压从海平面的基础值（PaO2G）72.4±9毫米汞柱降至海拔高度值（PaO2Alt）47.4±6毫米汞柱。PaO2G与PaO2Alt相关（r = 0.587；P<0.01）。多元回归分析显示，飞行前FEV1降低了方程中未由PaO2G解释的PaO2Alt的变异性：PaO2Alt = 0.453[PaO2G]+0.386[FEV1%预测值]+2.440（r = 0.847；P<0.001）。使用PaO2G的两个先前发表公式的残差也与FEV1相关（r≥0.765；P<0.001）。
在低压暴露期间，大多数患者的动脉血氧分压下降至具有临床意义的水平。对于患有严重慢性阻塞性肺疾病的患者，将飞行前地面动脉血氧分压（PaO2G）与飞行前FEV1测量值相结合，可改善对海拔高度时PaO2（PaO2Alt）的预测。
