Prolonged Air Leak After Pulmonary Resection Increases Risk of Noncardiac Complications, Readmission, and Delayed Hospital Discharge: A Propensity Score-adjusted Analysis.

OBJECTIVE: The aim of the study was to determine whether prolonged air leak (PAL) is associated with postoperative morbidity and mortality following pulmonary resection after adjusting for differences in baseline characteristics using propensity score analysis. SUMMARY BACKGROUND DATA: Patients with PAL after lung resection have worse outcomes than those without PAL. However, adverse postoperative outcomes may also be secondary to baseline risk factors, such as poor lung function. METHODS: Patients who underwent pulmonary resection for lung cancer/nodules (1/2009-6/2014) were stratified by the presence of PAL [n = 183 with/1950 without; defined as >5 d postoperative air leak; n = 189 (8.3%)]; probability estimates for propensity for PAL from 31 pretreatment/intraoperative variables were generated. Inverse probability-of-treatment weights were applied and outcomes assessed with logistic regression. RESULTS: Standardized bias between groups was significantly reduced after propensity weighting (mean = 0.18 before vs 0.08 after, P < 0.01). After propensity weighting, PAL was associated with increased odds of empyema (OR = 8.5; P < 0.001), requirement for additional chest tubes for pneumothorax (OR = 7.5; P < 0.001), blood transfusion (OR = 2; P = 0.03), pulmonary complications (OR = 4; P < 0.001), unexpected return to operating room (OR = 4; P < 0.001), and 30-day readmission (OR = 2; P = 0.009). Among other complications, odds of cardiac complications (P = 0.493), unexpected ICU admission (P = 0.156), and 30-day mortality (P = 0.270) did not differ. Length of hospital stay was prolonged (5.04 d relative effect, 95% confidence interval, 3.77-6.30; P < 0.001). CONCLUSIONS: Pulmonary complications, readmission, and delayed hospital discharge are directly attributable to having a PAL, whereas cardiac complications, unexpected admission to the ICU, and 30-day mortality are not after propensity score adjustment.

A clinical prediction model for prolonged air leak after pulmonary resection.

OBJECTIVE: Prolonged air leak increases costs and worsens outcomes after pulmonary resection. We aimed to develop a clinical prediction tool for prolonged air leak using pretreatment and intraoperative variables. METHODS: Patients who underwent pulmonary resection for lung cancer/nodules (from January 2009 to June 2014) were stratified by prolonged parenchymal air leak (>5 days). Using backward stepwise logistic regression with bootstrap resampling for internal validation, candidate variables were identified and a nomogram risk calculator was developed. RESULTS: A total of 2317 patients underwent pulmonary resection for lung cancer/nodules. Prolonged air leak (8.6%, n = 200) was associated with significantly longer hospital stay (median 10 vs 4 days; P < .001). Final model variables associated with increased risk included low percent forced expiratory volume in 1 second, smoking history, bilobectomy, higher annual surgeon caseload, previous chest surgery, Zubrod score >2, and interaction terms for right-sided thoracotomy and wedge resection by thoracotomy. Wedge resection, higher body mass index, and unmeasured percent forced expiratory volume in 1 second were protective. Derived nomogram discriminatory accuracy was 76% (95% confidence interval [CI], 0.72-0.79) and facilitated patient stratification into low-, intermediate- and high-risk groups with monotonic increase in observed prolonged air leaks (2.0%, 8.9%, and 19.2%, respectively; P < .001). Patients at intermediate and high risk were 4.80 times (95% CI, 2.86-8.07) and 11.86 times (95% CI, 7.21-19.52) more likely to have prolonged air leak compared with patients at low risk. CONCLUSIONS: Using readily available candidate variables, our nomogram predicts increasing risk of prolonged air leak with good discriminatory ability. Risk stratification can support surgical decision making, and help initiate proactive, patient-specific surgical management.