Background and Objectives: The estimation of lung function impairment after pulmonary lobectomy for primary non-small cell lung cancer (NSCLC) has been of great interest since the reduction of respiratory function might severely affect a patient's quality of life. The perioperative factors that may have an influence on widening the gap between the postoperative measured lung function and predicted postoperative lung function were our greatest concern. We aimed to analyze the perioperative patient factors that may influence postoperative lung function in patients undergoing pulmonary lobectomy. Materials and Methods: A retrospective study was conducted using the medical records of 199 patients who underwent lobectomy for lung cancer between July 2017 and May 2020. After comparing the achieved postoperative forced expiratory volume in 1 s (FEV1) and predicted postoperative (ppo) FEV1, patients were divided into two groups: group A (n = 127), who had preserved pulmonary lung function; and group B (n = 72), who had decreased pulmonary lung function. Primary endpoints included location of pulmonary resection, preoperative performance status, body mass index (BMI) on admission, total muscle area, and muscle index. Results In group A, the proportion of normal weighted patients was significantly higher than that in group B (67.7% vs. 47.2%, p = 0.003). Conversely, the proportion of overweight patients was significantly higher in group B than in group A (47.2% vs. 28.3%, p = 0.003). Group B had a significantly high incidence of upper lobe resection (p = 0.012). The mean total muscle area in group A was higher than that in group B, but the difference was not statistically significant. Conclusions: A greater decrease in postoperative lung function than in ppo FEV1 was associated with BMI and the location of pulmonary resection in patients who underwent lobectomy. Postoperative physiologic changes due to high BMI and the resection of upper lobes need to be discussed to prevent postoperative morbidities.
Keywords: body mass index; lobectomy; lung function test.