Introduction Postoperative pulmonary complications (PPCs) significantly impact recovery after thoracic surgery. Postoperative diaphragmatic dysfunction (PDD) may be a key risk factor but remains under-recognized, particularly regarding comparative data between video-assisted thoracoscopic surgery (VATS) and robot-assisted thoracic surgery (RATS). This study aims to investigate the association between PDD detected by point-of-care ultrasound (POCUS) and PPCs following minimally invasive thoracic surgery. Methods This is a single-center, prospective observational study conducted at the Affiliated Cancer Hospital of Guangzhou Medical University. A total of 148 patients scheduled for elective pulmonary resection (VATS or RATS) will be enrolled. Diaphragmatic function will be assessed using POCUS at four time points: 1 day preoperatively (T0), 30 min post-extubation (T1), and on postoperative day 1 (T2) and 3 (T3). The primary measurements include diaphragmatic excursion (DE) and diaphragmatic thickening fraction (DTF). The primary endpoint is the incidence of PDD (defined as DE 10 mm or negative) on postoperative day 1. Secondary endpoints include the incidence and severity of PPCs within 7 days postoperatively (defined by European Perioperative Clinical Outcome criteria), serial changes in DE and DTF, pain scores, and quality of recovery (QoR-15). Propensity score matching and multivariate regression will be used to adjust for confounders. Conclusion This study will elucidate the relationship between POCUS-detected PDD and PPCs in patients undergoing VATS and RATS. The findings may support the integration of diaphragmatic ultrasound into perioperative risk stratification and guide targeted preventive strategies to improve postoperative outcomes. Trial registration https://www.chictr.org.cn , ChiCTR2500103734.
Li et al. (Mon,) studied this question.