Carbon monoxide lung diffusion capacity improves risk stratification in patients without airflow limitation: evidence for systematic measurement before lung resection.

OBJECTIVE: In many centers, carbon monoxide lung diffusion capacity (DLCO) is still not routinely measured in all patients but only in patients with airflow limitation. The objective of the study was to assess the degree of correlation between forced expiratory volume in 1s (FEV1) and DLCO, and verify whether a low predicted postoperative DLCO (ppoDLCO) could have a role in predicting complications in patients without airflow limitation. METHODS: We analyzed 872 patients submitted to lung resection between January 2000 and December 2004 in two units measuring systematically DLCO before operation. Correlation between FEV1 and DLCO was assessed in the entire dataset and in different subsets of patients. A number of variables were then tested for a possible association with postoperative cardiopulmonary complications in patients with FEV1>80% by univariate analysis. Variables with p<0.10 at univariate analysis were used as independent variables in a stepwise logistic regression analysis (dependent variable: presence of cardiopulmonary morbidity), which was in turn validated by bootstrap analysis. RESULTS: The correlation coefficients between FEV1 and DLCO in the entire dataset and in different subsets of lung resection candidates (stratified by age, gender, cause of operation, airflow limitation) were all below 0.5, showing a modest degree of correlation. Two hundred and nineteen of the 508 patients (43%) with FEV1>80% had DLCO<80%. Moreover, in patients with FEV1>80%, logistic regression analysis showed that ppoDLCO<40% was a significant and reliable predictor of postoperative complications (p=0.004). CONCLUSION: The modest correlation between FEV1 and DLCO and the capacity of ppoDLCO to discriminate between patients with and without complications in subjects with a normal FEV1, warrants the routine measurement of DLCO in all candidates for lung resection, irrespective of their FEV1 value, in order to improve surgical risk stratification.

Alternate suction reduces prolonged air leak after pulmonary lobectomy: a randomized comparison versus water seal.

BACKGROUND: The objective of the present study was to compare in a prospective randomized fashion two different management schemes for chest tubes after lobectomy: water seal versus alternate suction (suction overnight and water seal during the day). METHODS: Ninety-four patients with air leak on the morning of the first postoperative day were randomly assigned to two groups: group 1 (water seal alone), 47 patients; or group 2 (alternate suction), 47 patients. The groups were then compared in terms of preoperative, operative, and postoperative variables. RESULTS: Alternate suction patients showed a reduced incidence of air leak longer than 4 days (p = 0.04) and longer than 7 days (p = 0.02), a shorter duration of chest tubes in place (p = 0.002), and a shorter postoperative hospital stay (p = 0.004). CONCLUSIONS: Alternate suction was superior to water seal alone in reducing the incidence of prolonged air leak and postoperative hospital stay after lobectomy. As suction was applied only overnight, this modality has the same advantage of water seal in terms of early mobilization of patients.