Assessment of operative risk in patients undergoing lung resection: Importance of predicted pulmonary function

Objective: To evaluate the ability of preoperative variables to identify patients at increased risk for complications after lung resection and the usefulness of predicted postoperative FEV₁ as a marker of risk for adverse outcomes. Design: Prospective analysis of a cohort of patients undergoing pulmonary resection. Complication rates were analyzed according to preoperative pulmonary variables, demographic variables, procedure performed, and predicted postoperative FEV₁. Predicted postoperative FEV₁ was calculated using a formula estimating the decline in preoperative FEV₁ based on the number of bronchopulmonary segments removed during surgery. Setting: A major teaching hospital and tertiary referral center. Patients: A consecutive series of patients undergoing pulmonary resection. Measurements and main results: Medical complications were recorded as part of an ongoing clinical database. The overall complication rate was low (17 percent rate of any complication, 1 percent death rate). Univariate predictors of complications included age ≥60, male sex, history of smoking, a pneumonectomy procedure, and a low predicted postoperative FEV₁. Hypercarbia (≥45 mm Hg) on preoperative arterial glood gas analysis, desaturation on exercise oximetry (≤90 percent), and a preoperative FEV₁ less than 1 L were not predictive of complications. When the effect of these variables was controlled for in a multivariate analysis, a low predicted postoperative FEV₁ remained the only significant independent predictor of complications. For each 0.2 L decrease in predicted FEV₁, the odds ratio for complications was 1.46 (95 percent confidence interval [CI] 1.2 to 1.8). Conclusions: A low predicted postoperative FEV₁ appears to be the best indicator of patients at high risk for complications, and it was the only significant correlate of complications when the effect of other potential risk factors was controlled for in a multivariate analysis. Pulmonary resection should not be denied on the basis of traditionally cited preoperative pulmonary variables, and a prediction of postoperative pulmonary function by a technique of simple calculation may be useful to identify patients at increased risk for medical complications.