Predictive value of preoperative T cell phenotypes for postoperative pulmonary complications in elderly patients undergoing thoracic surgery.

Background: Postoperative pulmonary complications (PPCs) significantly impair patient recovery, yet reliable predictors remain scarce. T cell and mitochondrial phenotypic marker abnormalities are recognized as key mechanisms underlying immune dysregulation. Accordingly, we hypothesized that quantifying these T cell characteristics could serve as a novel predictive strategy for PPCs. Methods: Patients who underwent elective thoracic surgery under general anesthesia were enrolled in this study. Preoperative venous blood samples were collected to measure T cell subsets and their mitochondrial function indicators. Results: The occurrence of PPCs was evaluated postoperatively. Among the 176 enrolled patients, 44 (25.0%) developed PPCs. Compared with the non-PPCs group, patients in the PPCs group were older, had longer operative time, and exhibited significantly higher preoperative levels of C-reactive protein, neutrophils, white blood cells, prothrombin time, activated partial thromboplastin time, fibrinogen degradation products, D-dimer, and international normalized ratio, while the preoperative lymphocyte percentage was significantly lower ( Conclusions: Thus, preoperative measurement of T cell subsets indicators may aid in early identification and risk stratification of PPCs after thoracic surgery.