Merit of preoperative clinical findings and functional pulmonary evaluation as predictors of postoperative pulmonary complications.

OBJECTIVE To assess the relationship of clinical data and the results of preoperative pulmonary functional evaluation with postoperative pulmonary complications. METHODS We conducted a retrospective cohort study with patients who underwent pulmonary functional evaluation over a period of 5 years. We analyzed clinical, demographic and spirometric data, surgical procedures performed and postoperative pulmonary complications. RESULTS We analyzed the medical records of 521 patients. Mean age was 59.5 ± 14 years, 65.8% were male, and 93.4% were white. Mean FEV1 was 76.6 ± 24.6% of predicted. There were clinical comorbidities in 73.5% of all cases (COPD in 29.8%). The most common surgical sites were thorax (n = 122; 23.4%) and upper abdomen (n = 117; 22.5%). Postoperative pulmonary complications occurred in 99 patients (19.0%), with respiratory failure being the most common (4.6%). Forty-three (8.3%) patients died. Rates of pulmonary complications were higher after thoracic (28.9%), cardiac (28%) and upper abdomen surgery (24.3%) (p ≤ 0.0001). Most patients (66.7%) with pulmonary complications were classified as ASA III or IV (p<0.01), and in 70.2% of operations, time on anesthesia was > 3.5 hours (p ≤ 0.0001). The difference in median length of hospital stay between patients with and without pulmonary complications was statistically significant (23.5 [15.8-34] days vs. 10 [6-18] days; p<0.001). Patients who had never smoked had fewer complications than those with current or past smoking history (p=0.04). We did not detect significant associations between postoperative pulmonary complications and presence of COPD, FEV1 or body mass index (p>0.05). CONCLUSION The most important factors associated with postoperative pulmonary complications were surgical site, time of anesthesia, and ASA classification.