O'Brien G M, Furukawa S, Kuzma A M, Cordova F, Criner G J
Department of Medicine and Cardiothoracic Surgery, Temple University School of Medicine, Philadelphia, PA 19140, USA.
Chest. 1999 Jan;115(1):75-84. doi: 10.1378/chest.115.1.75.
To determine the impact of preoperative resting hypercapnia on patient outcome after bilateral lung volume reduction surgery (LVRS).
We prospectively examined morbidity, mortality, quality of life (QOL), and physiologic outcome, including spirometry, gas exchange, and exercise performance in 15 patients with severe emphysema and a resting PaCO2 of > 45 mm Hg (group 1), and compared the results with those from 31 patients with a PaCO2 of < 45 mm Hg (group 2).
All preoperative physiologic and QOL indices were more impaired in the hypercapnic patients than in the eucapnic patients. The hypercapnic patients exhibited a lower preoperative FEV1, a lower diffusing capacity of the lung for carbon monoxide, a lower ratio of PaO2 to the fraction of inspired oxygen, a lower 6-min walk distance, and higher oxygen requirements. However, after surgery both groups exhibited improvements in FVC (group 1, p < 0.01; group 2, p < 0.001), FEV1 (group 1, p=0.04; group 2, p < 0.001), total lung capacity (TLC; group 1, p=0.02; group 2, p < 0.001), residual volume (RV; group 1, p=0.002; group 2, p < 0.001), RV/TLC ratio (group 1, p=0.03; group 2, p < 0.001), PaCO2 (group 1, p=0.002; group 2, p=0.02), 6-min walk distance (group 1, p=0.005; group 2, p < 0.001), oxygen consumption at peak exercise (group 1, p=0.02; group 2, p=0.02), total exercise time (group 1, p=0.02; group 2, p=0.02), and the perceived overall QOL scores (group 1, p=0.001; group 2, p < 0.001). However, because the magnitude of improvement was similar in both groups, and the hypercapnic group was more impaired, the spirometry, lung volumes, and 6-min walk distance remained significantly lower post-LVRS in the hypercapnic patients. There was no difference in mortality between the groups (p=0.9).
Patients with moderate to severe resting hypercapnia exhibit significant improvements in spirometry, gas exchange, perceived QOL, and exercise performance after bilateral LVRS. The maximal achievable improvements in postoperative lung function are related to preoperative level of function; however, the magnitude of improvement can be expected to be similar to patients with lower resting PaCO2 levels. Patients should not be excluded from LVRS based solely on the presence of resting hypercapnia. The long-term benefit of LVRS in hypercapnic patient remains to be determined.
确定术前静息性高碳酸血症对双侧肺减容手术（LVRS）后患者预后的影响。
我们前瞻性地研究了15例重度肺气肿且静息动脉血二氧化碳分压（PaCO2）>45 mmHg的患者（第1组）的发病率、死亡率、生活质量（QOL）和生理指标，包括肺量计、气体交换和运动能力，并将结果与31例PaCO2<45 mmHg的患者（第2组）进行比较。
高碳酸血症患者术前所有生理和生活质量指标的受损程度均高于正常碳酸血症患者。高碳酸血症患者术前第一秒用力呼气容积（FEV1）较低、肺一氧化碳弥散量较低、动脉血氧分压与吸入氧分数比值较低、6分钟步行距离较短且氧需求较高。然而，术后两组患者的用力肺活量（FVC，第1组，p<0.01；第2组，p<0.001）、FEV1（第1组，p=0.04；第2组，p<0.001）、肺总量（TLC；第1组，p=0.02；第2组，p<0.001）、残气量（RV；第1组，p=0.002；第2组，p<0.001）、RV/TLC比值（第1组，p=0.03；第2组，p<0.001）、PaCO2（第1组，p=0.002；第2组，p=0.02）、6分钟步行距离（第1组，p=0.005；第2组，p<0.001）、运动峰值时的氧耗量（第1组，p=0.02；第2组，p=0.02）、总运动时间（第1组，p=0.02；第2组，p=0.02）以及总体生活质量评分（第1组，p=0.001；第2组，p<0.001）均有改善。然而，由于两组改善幅度相似，且高碳酸血症组受损更严重，因此高碳酸血症患者LVRS术后的肺量计、肺容积和6分钟步行距离仍显著较低。两组间死亡率无差异（p=0.9）。
中度至重度静息性高碳酸血症患者在双侧LVRS术后肺量计、气体交换、生活质量和运动能力均有显著改善。术后肺功能的最大可实现改善与术前功能水平相关；然而，改善幅度预计与静息PaCO2水平较低的患者相似。不应仅因存在静息性高碳酸血症而将患者排除在LVRS之外。LVRS对高碳酸血症患者的长期益处仍有待确定。
