Multivariate analysis of risk factors for postoperative pneumonia

Purpose Many risk factors for postoperative pneumonia have been identified, but those for the progression from atelectasis to pneumonia have been poorly examined. We undertook the present study to find risk factors for the progression from atelectasis to pneumonia. Patients and methods We completed a retrospective analysis of 2,969 patients who underwent major abdominal surgery during the past 13 years. Results Pneumonia developed in 45 patients (1.5%), and postoperative atelectasis with a high risk for the subsequent infection occurred in 44 patients in whom pneumonia did not develop. A series of 13 variables was compared in the two patient categories. By multivariate discriminant analysis, we identified three independent significant correlates of the development of postoperative pneumonia: blood loss of more than 1,200 mL during surgery, age over 65 years, and preoperative utilization of inhalation therapy devices. Conclusion This study shows that a substantial number of cases of postoperative pneumonia can be prevented.