Risk factors of postoperative pneumonia after lung cancer surgery

The purpose of this study was to investigate risk factors of postoperative pneumonia (POP) after lung cancer surgery. The 417 lung cancer patients who underwent surgical resection in a tertiary referral hospital were included. Clinical, radiological and laboratory data were reviewed retrospectively. Male and female ratio was 267:150 (median age, 65 yr). The incidence of POP was 6.2% (26 of 417) and in-hospital mortality was 27% among those patients. By univariate analysis, age ≥ 70 yr (P < 0.001), male sex (P = 0.002), ever-smoker (P < 0.001), anesthesia time ≥ 4.2 hr (P = 0.043), intraoperative red blood cells (RBC) transfusion (P = 0.004), presence of postoperative complications other than pneumonia (P = 0.020), forced expiratory volume in 1 second/forced vital capacity (FEV ₁/FVC) < 70% (P = 0.002), diffusing capacity of the lung for carbon monoxide < 80% predicted (P = 0.015) and preoperative levels of serum C-reactive protein ≥ 0.15 mg/dL (P = 0.001) were related with risk of POP. Multivariate analysis showed that age ≥ 70 yr (OR = 3.563, P = 0.014), intraoperative RBC transfusion (OR = 4.669, P = 0.033), the presence of postoperative complications other than pneumonia (OR = 3.032, P = 0.046), and FEV ₁/FVC < 70% (OR = 3.898, P = 0.011) were independent risk factors of POP. In conclusion, patients with advanced age, intraoperative RBC transfusion, postoperative complications other than pneumonia and a decreased FEV ₁/FVC ratio have a higher risk for pneumonia after lung cancer surgery.