Prophylactic Low-Dose Dexamethasone for Postoperative Pulmonary Complications in Type B Aortic Dissection: A Retrospective Cohort Study

AIM: To evaluate the impact of prophylactic low-dose glucocorticoids on the incidence of postoperative pulmonary complications (PPCs) and perioperative recovery parameters in patients undergoing surgery for type B aortic dissection.METHODS: This retrospective cohort study analyzed 240 patients who underwent type B aortic dissection (TBAD) surgery at Taizhou Hospital of Zhejiang Province Affiliated to Wenzhou Medical University from January 2023 to December 2025. Patients were divided into an intervention group (n = 118) receiving a single dose of dexamethasone (5 mg intravenously) after anesthesia induction and a control group (n = 122) receiving standard care. To minimize selection bias, propensity score matching (PSM) was performed using 1:1 nearest neighbor matching with a caliper of 0.2 times the standard deviation of the propensity score. Covariates included age, sex, body mass index, diabetes, smoking history, preoperative C-reactive protein, preoperative PaO2/FiO2 ratio, operative time, intraoperative blood transfusion volume, and surgical procedure (thoracic endovascular aortic repair [TEVAR] vs. open surgery). After matching, 93 well-balanced pairs were obtained. The primary outcome was the incidence of PPCs within 30 days postoperatively. Secondary outcomes included the duration of mechanical ventilation, intensive care unit (ICU) and hospital length of stay, as well as postoperative inflammatory markers (C-reactive protein [CRP], white blood cell [WBC]) and oxygenation (PaO2/FiO2 ratio) at 24 hours.RESULTS: After PSM, baseline characteristics were well balanced between groups, with all standardized mean differences <0.1. The intervention group showed a significantly lower incidence of PPCs compared to the control group (20.43% vs. 34.41%, p = 0.033). The intervention was also associated with significantly shorter mechanical ventilation duration (p = 0.008), ICU stay (p = 0.003), and total hospital stay (p = 0.009). Additionally, the intervention group demonstrated significantly lower postoperative CRP and WBC levels and a higher PaO2/FiO2 ratio at 24 hours (all p < 0.001). No significant differences were observed in safety outcomes including new-onset infection, wound healing impairment, or hyperglycemia.CONCLUSIONS: Prophylactic low-dose glucocorticoids were associated with a lower incidence of PPCs and improved perioperative recovery in patients undergoing TBAD surgery, including shorter ventilation time and the length of hospital stay, attenuated inflammatory response, and better oxygenation. These findings suggest potential clinical benefits with a favorable safety profile, but causality cannot be inferred due to the retrospective design. Therefore, prospective multicenter studies are warranted to validate these results.