Postoperative pneumonia. Determinants of mortality.

Postoperative pneumonia continues to be a major cause of mortality on surgical services. The determinants that affect survival in patients in whom postoperative pneumonia develops are not clearly defined. We completed a retrospective analysis of 136 patients in whom postoperative pneumonia developed after they had major operative procedures between 1974 and 1980. These patients represented 1.3% of all operative cases, yet comprised 10% of the total 614 patients who died during the study period. The average age of the patients in whom pneumonia developed was 66 years. Significant determinants of death by chi 2 analysis included gram-negative pneumonitis, emergent operation, respirator-acquired pneumonia, postoperative peritonitis, and several factors that suggested that host defenses were overwhelmed (remote organ failure, positive blood cultures, or spread of infection to the second lung). We concluded that postoperative pneumonia is a disease of elderly patients and that survival depends on the ability of the surgeon to help the patient localize and resist the challenge presented by virulent gram-negative organisms.