Analysis of risk factors for pulmonary infection after thoracoscopic pneumonectomy and the predictive value of laboratory-related indicators
Authors: Zhang Jumei , Tu Rui , Guan Fasheng , Zhang Limei , Liu Li 
Published: March 2023

Abstract
Objective: To investigate the risk factors and the predictive value of laboratory-related indexes for complications of pulmonary infections after lung resection by video-assisted thoracoscopic surgery (VATS).
Methods: The clinical data and laboratory test results of 200 patients who underwent VATS lung resection at the Affiliated Hospital of Southwestern Medical University from December 2021 to July 2022 were retrospectively analyzed. Univariate and multifactorial logistic regression were used to analyze whether their gender, age, (American Society of Anesthesiologists) ASA classification, duration of surgery, intraoperative bleeding, days of hospitalization, hypoproteinemia, diabetes mellitus, smoking index, and underlying lung disease were risk factors for postoperative pulmonary infection. The levels of preoperative and early postoperative nutritional parameters (serum albumin, prealbumin) and inflammatory cells (total leukocyte count, neutrophil count, neutrophil ratio) were measured and compared 24 h after surgery. ROC curve analysis of the predictive effect of inflammatory cells on postoperative pulmonary infection.
Results: In 200 patients undergoing pulmonary VATS, 42 cases of postoperative pulmonary infection occurred, with an infection rate of 21%. Univariate analysis showed statistically significant differences in gender, age, presence of hypoproteinemia, length of hospital stay, smoking index, presence of underlying pulmonary disease, presence of diabetes mellitus, duration of surgery, intraoperative bleeding, and ASA classification between those with and without postoperative pulmonary VATS (p <0.05). Multifactorial logistic regression analysis showed that the presence of underlying lung disease (OR = 3.065), presence of diabetes (OR = 5.123), duration of surgery (≥120 min) (OR = 4.641), and length of hospital stay >7 days (OR = 7.428) were independent risk factors for pulmonary infection after pulmonary VATS (p<0.05). Preoperative pulmonary infected patients had lower albumin and prealbumin levels than those without pulmonary infection, and higher white blood cell count and neutrophil count than those without pulmonary infection. Pre-albumin was lower in those with postoperative 24 h pulmonary infection than in those without pulmonary infection, and leukocyte count and neutrophil count were higher than in those without pulmonary infection, and the difference was statistically significant (p<0.05). According to the results of the ROC curve, the area under the curve for leukocytes and neutrophils at 24 h postoperatively was 0.684 (95% CI: 0.595-0.773, P<0.001) and 0.675 (95% CI:0.587-0.764, P<0.001), respectively, and the area under the curve for combined inflammatory cells to predict lung infection was 0.702 (95%CI:0.615-0.790, P<0.001).
Conclusion: Patients with combined underlying lung disease, diabetes mellitus, operative time >120 min, and length of hospital stay >7 days were independent risk factors for post-thoracoscopic complications of pulmonary infection, and low early nutritional indicators and abnormal laboratory infection indicators were associated with the development of postoperative pulmonary infection. The preoperative and 24 h postoperative levels of inflammatory cells had some predictive value for a lung infection.