Predictive value of pulmonary function measures for short-term outcomes following lung resection: analysis of a single high-volume institution
Despite the importance of preoperative risk-stratification, there is a lack of consensus on how to identify high-risk patients for pulmonary resection. Enrollment criteria for national trials propose one definition based on preoperative pulmonary function tests. We sought to examine the value of preoperative forced expiratory volume in 1 second (FEV1) and diffusion capacity for carbon monoxide (DLCO) to predict short-term outcomes following pulmonary resection. Using our institutional Society of Thoracic Surgeons (STS) database we identified 419 consecutive lung cancer patients who presented to our institution for pulmonary resection between 2012 and 2016. We identified patients as “high risk” based on the national trial criteria of FEV1 or DLCO ≤50%. Our primary outcome was any postoperative complication within 30 days of surgery. Secondary outcomes included cardiac and pulmonary complications, 30-day readmission, and discharge disposition. DLCO ≤50% was associated with any postoperative complication (P=0.03), but not predictive of cardiac events, pulmonary complications, or 30-day readmission. There were no significant differences in any of these short-term outcomes for patients with FEV1 ≤50%. On multivariable analysis, neither FEV1 nor DLCO ≤50% were significantly associated with occurrence of postoperative complication (OR =1.67, 95% CI: 0.60–4.63; OR =1.66, 95% CI: 0.96–2.86, respectively). Notably, DLCO ≤50%—but not FEV1—was associated with discharge to a skilled facility on univariate (P=0.01) and multivariable analysis (OR =2.54; 95% CI: 1.08–5.99; P=0.03). This association between DLCO and discharge to a skilled facility persisted when DLCO was used as a continuous variable. For all-comers presenting to our institution for lung cancer resection, classification based on FEV1 or DLCO ≤50% may not reliably identify those at highest risk for short-term postoperative complications. While our findings suggest caution when using pulmonary parameters in isolation, the potential value of DLCO as a proxy for underlying comorbidity warrants further investigation.