Incidence and predictors of postoperative pneumonia after cardiothoracic surgery

Aims: The objective of this study was to examine risk factors and predictors that contribute to the development of postoperative pneumonia (POP) following cardiothoracic surgery. Methods: This was a prospective, observational study including patients who underwent major cardiothoracic surgery and survived the initial 48 postoperative hours. POP was diagnosed based on the Centers for Disease Control and Prevention criteria. Preoperative, intraoperative, and postoperative variables were analyzed to determine their association with the occurrence of POP. Results: A total of 278 consecutive patients (mean age: 51±22.91 years, male sex 68%) were included in the study. POP incidence was 6.87 per 1000 days of hospitalization. Significant risk factors for POP were identified as history of renal disease [odds ratio (OR) 3.9, 95% confidence interval (CI) 1.1-13.5, p=0.040)], central nervous system disorder (OR 12.8, 95% CI 4-40.5, p<0.001), postoperative aspiration (p=0.008), absence of respiratory exercise after surgery (OR 2.5, 95% CI 1-6.3, p=0.041), and presence of postoperative complications other than pneumonia (e.g. acute renal failure) (OR 7.2, 95% CI 2.3-22, p=0.002). Patients with POP had significantly longer mechanical ventilation (p<0.001), hospitalization (p<0.001), and mobilization durations (p=0.006) than those without pneumonia. Multivariate analysis revealed that prolonged postoperative mobilization duration (OR 1.8, 95% CI 1.08-2.84, p=0.022), presence of postoperative complications other than pneumonia (OR 12.7, 95% CI 1.73-92.31, p=0.012), and longer postoperative hospitalization duration (OR 1.1, 95% CI 1.02-1.19, p=0.011) were independent predictors of POP. Conclusions: This study demonstrates that POP remains a considerable complication after cardiothoracic surgery. Pre-existing renal and neurologic disorders, postoperative aspiration, and inadequate respiratory exercises were identified as major risk factors. Prolonged postoperative mobilization duration, and longer postoperative hospitalization duration along with the presence of other postoperative complications, were identified as independent predictors of POP, highlighting the need for early risk stratification and targeted preventive strategies.