An optimal protective ventilation strategy in lung resection surgery: a prospective, single-center, three-arm randomized controlled trial

Protective ventilation reduces ventilator-induced acute lung injury postoperatively; however, the optimal strategy for one-lung ventilation (OLV) remains unclear. This study compared three protective ventilation strategies with a postoperative partial pressure of oxygen (PaO₂)/fraction of inspired oxygen (FiO₂) ratio to reduce the incidence of immediate postoperative pulmonary complications (PPCs) in patients undergoing lung resection surgery. Eighty-seven patients with ASA physical status I-III requiring OLV for lung resection surgery were randomized into three groups according to the applied ventilation strategies: low tidal volume (V_T) of 4 mL/kg of predicted body weight (PBW) (LV group), medium V_T of 6 mL/kg of PBW (MV group), and high V_T of 8 mL/kg of PBW (HV group). All patients received 5 cmH₂O of positive end-expiratory pressure (PEEP). The primary outcome was the mean difference of PaO₂/FiO₂ ratio after surgery. The radiologic findings of acute lung injuries were also evaluated. The incidence of immediate PPCs was determined by PaO₂/FiO₂ ratio of < 300 mmHg and/or newly developed radiological findings within 72 h after surgery. The MV group showed the highest PaO₂/FiO₂ ratio at 6 h postoperatively (P = 0.010). There were no significant among-group differences in radiological findings in 3 postoperative days. The MV group showed the lowest incidence of immediate PPCs among the three groups (P = 0.007). During OLV in lung resection surgery, protective ventilation at a V_T of 6 mL/kg with PEEP of 5 cmH₂O may achieve a higher postoperative PaO₂/FiO₂ ratio, reducing the incidence of immediate PPCs.