Effects of individualized PEEP titration on intraoperative cardiac output in thoracoscopic lung surgery: a prospective randomized trial

Personalized positive end-expiratory pressure (PEEP) based on pulmonary compliance may improve intraoperative hemodynamics and postoperative outcomes in thoracic surgery. This study aimed to evaluate the effect of individualized, compliance-guided PEEP titration on cardiac output (CO) and postoperative pulmonary complications (PPCs) in patients undergoing video-assisted thoracoscopic pulmonary resection. In this prospective randomized controlled trial, 80 patients scheduled for thoracoscopic pulmonary resection were allocated to either an individualized PEEP group (Group N) or a fixed PEEP group (Group C). Group N received dynamic PEEP titration starting at 15 cmH₂O, adjusted to optimize compliance; Group C received a fixed PEEP of 5 cmH₂O. Hemodynamic parameters including CO, heart rate (HR), and systemic vascular resistance (SVR) were recorded at five time points: baseline after admission (T1), 20 min after initiating two-lung ventilation (T2), 30 min following PEEP implementation (T10), 60 min post-PEEP adjustment (T11), and upon completion of one-lung ventilation (T12). PPCs and postoperative pneumonia incidence were also recorded. Seventy-six patients completed the study (n = 38 per group). At T11, T12, Group N showed significantly higher CO than Group C. The optimal PEEP range for compliance was 7-13 cmH₂O. Compared to 5 cmH₂O PEEP of individualized PEEP during OLV resulted in better lung compliance, lower driving pressure, and higher mean airway pressure, without differences in peak airway pressure or P_ETCO₂. Postoperative pulmonary complications (PPCs) occurred more frequently in Group C (42.1% vs. 13.2%, p = 0.004). No significant differences were observed in overall SVR trends between groups, except at T11, T12. Compliance-guided individualized PEEP improves cardiac output and may reduce postoperative pulmonary complications in patients undergoing thoracoscopic lung resection. This approach holds promise for enhancing perioperative respiratory and hemodynamic stability.Trial registration: ChiCTR2100048201, intervention study, registered on 04/07/2021.