Complications of lung resection and exercise capacity: A meta-analysis

Rationale: While exercise capacity, expressed as maximal oxygen consumption (VO_2max), has been proposed to be the best predictor of postoperative cardiopulmonary complications after surgical resection in lung cancer patients, the literature remains controversial. The purpose of this study was to use the meta-analytic approach to determine if VO_2max, expressed as either ml kg^-1 min^-1 or as a percentage of predicted, differed between patients who develop postoperative cardiopulmonary complications versus those that do not. Methods: Studies were retrieved via (1) computerized literature searches, (2) cross referencing from retrieved articles, and (3) expert review of our reference list. Trials were included if they reported preoperative VO_2max values (ml kg^-1 min^-1 or percentage of predicted) and had patients in which postoperative cardiopulmonary complications occurred. Results: Fourteen studies representing a total of 955 men and women met our criteria for inclusion. Across all designs and categories, random-effects modeling demonstrated that patients without postoperative pulmonary complications had significantly higher levels of VO_2max in ml kg^-1 min^-1 (mean difference=3.0, 95% confidence interval (CI), 1.9-4.0) as well as VO_2max as a percentage of predicted (mean difference=8, 95% CI, 3.3-12.8). Conclusion: After a systematic review of the literature, we found that exercise capacity, expressed as VO_2max, is lower in patients that develop clinically relevant complications after curative lung resection. These results are important for the practicing clinician because they answer the literature controversy on the usefulness of measuring preoperative exercise capacity and reinforce the current guidelines on decision making for lung resection.