Factors associated with the development of postoperative pneumonia in lung cancer surgery patients with perioperative oral management

Background: Postoperative pneumonia is a serious lung cancer surgery complication. Perioperative oral management can help prevent its development. Objectives: This study aimed to determine the characteristics of patients who developed postoperative pneumonia despite perioperative oral management. Methods: This study included 396 consecutive patients who underwent lung cancer surgery under general anesthesia at Fujita Health University Okazaki Medical Center from April 2020, the opening of the hospital, to the end of December 2023. Patient data, including age, gender, body mass index, underlying disease, smoking index, spirogram, operative time, amount of blood loss during operation, and operative procedure, were obtained from medical records. Oral examinations were conducted to determine the number of remaining teeth and whether dental caries are present and to examine tooth mobility and probing pocket depths > 4 mm. Furthermore, the patients were asked whether they had regular dental checkups. The patients were divided into the pneumonia and no-pneumonia groups following lung surgery, and the factors involved in postoperative pneumonia were investigated. Results: A total of 390 patients were analyzed (six were excluded), of whom 33 developed postoperative pneumonia. Among them, 17 were excluded from the analysis due to preoperative interstitial pneumonia. Consequently, the incidence of postoperative pneumonia was 16 of 373 patients (4.3%). Significant differences were observed between the groups in terms of age, sex, chronic obstructive pulmonary disease, smoking index, operative time, number of remaining teeth, and regular dental checkups. Logistic regression analysis using these significant items revealed that fewer than 20 remaining teeth were significantly associated with the development of postoperative pneumonia (p = 0.043). Conclusions: The results of this study indicated that the incidence of postoperative pneumonia following perioperative oral function management was maintained as low as that reported previously. The importance of dental intervention in the perioperative period was also elucidated. A high number of patients who developed postoperative pneumonia despite these interventions had fewer than 20 remaining teeth, suggesting that more attention should be paid to perioperative oral management, including the prevention of aspiration pneumonia.