Risk factors for postoperative pneumonia according to examination findings before surgery under general anesthesia

Objective This study was performed to determine the risk factors associated with postoperative complications after surgery under general anesthesia according to respiratory function test results and oral conditions. Materials and methods Preoperative examination data were collected for 471 patients who underwent surgery under general anesthesia at the Medical Hospital of Kyusyu University. Respiratory function tests, oral examinations, and perioperative oral management were performed in all patients. The incidence of and risk factors for postoperative complications were investigated. Classification and regression tree analyses were performed to investigate the risk factors for postoperative complications. Results Among the 471 patients, 11 developed postoperative pneumonia, 10 developed postoperative respiratory symptoms, and 10 developed postoperative fever. The most important risk factor for pneumonia was edentulism. Age, the Brinkman index, and head and neck surgery were also revealed as important risk factors for pneumonia. The O’Leary plaque control record (initial visit) was an important risk factor for postoperative respiratory symptoms. With respect to postoperative fever, a Hugh–Jones classification of grade > 1 was the most important risk factor; edentulism and a Brinkman index of > 642.5 were also found to be risk factors. Conclusion In addition to respiratory function tests, oral examinations may be important for the prediction of postoperative complications. Additionally, improved oral hygiene may be effective in preventing postoperative respiratory complications. Clinical relevance Risk factors for postoperative complications should be comprehensively evaluated using both respiratory function tests and oral findings.