Background: Despite advances in treatment, postoperative pneumonia remains a major problem after esophagectomy. Lung age has been proposed as a comprehensive indicator for respiratory function. The aim of this study is to reveal the efficacy of lung age in predicting occurrence of pneumonia after esophagectomy.
Methods: We assessed 342 consecutive patients who underwent subtotal esophagectomy for primary esophageal cancer from 2011 to 2014. Lung age was calculated from the preoperative spirometric test using the methods advocated by the Japanese Respiratory Society. We investigated factors predicting the occurrence of postoperative pneumonia after esophagectomy.
Results: The incidence of postoperative pneumonia was 28.9 %. According to the Clavien-Dindo classification, grade II and grade III-V pneumonia were observed in 21.3 and 7.6 % patients, respectively. In multivariate logistic regression analysis for the factors predicting the occurrence of postoperative pneumonia, higher lung age (p = 0.010) and lower body mass index (p = 0.006) were independent factors. Patients with grade III-V pneumonia tended to have higher lung age than those with grade II pneumonia (p = 0.084). In addition, lung age was significantly higher in patients who experienced pneumonia within postoperative days 7 than those who experienced pneumonia after postoperative days 7 (p = 0.028).
Conclusion: Spirometric lung age was associated with occurrence, severity, and time of onset of postoperative pneumonia after esophagectomy. This simple parameter deserves a greater consideration as a predictor of postoperative pneumonia after esophagectomy and can support both surgeons and patients in understanding the status of respiratory function.