PROtective Ventilation with a low versus high Inspiratory Oxygen fraction(PROVIO) and its effects on postoperative pulmonary complications:protocol for a randomized controlled trial

Abstract Background: Postoperative pulmonary complications (PPCs) is the most common perioperative complication following surgical site infection (SSI), which prolongs the hospital stay and increases health care cost. Lung-protective ventilation strategy is considered as better practice in abdominal surgery to prevent PPCs. However, the role of inspiratory oxygen fraction (FiO₂) in the strategy remains disputable. Previous trials have focused on reducing SSI by increasing inhaled oxygen concentration but higher FiO₂ (80%) was found to be associated with a greater incidence of atelectasis and mortality in recent researches. The trial aims at comparing the effect of FiO₂ added to lung-ventilation strategy on reducing the incidence of PPCs during general anesthesia for abdominal surgery. Methods: PROtective Ventilation with a low versus high Inspiratory Oxygen fraction trial（PROVIO）is a single-center, prospective, randomized, controlled trial planning to recruit 252 patients under abdominal surgery lasting for at least 2 hours. The patients will be randomly assigned to (1) a low FiO₂ (30% FiO₂) group and (2) a high FiO₂ (80% FiO₃) in lung-protective ventilation strategy. The primary outcome of the study is the occurrence of PPCs within the postoperative 7 days. Secondary outcomes include the severity grade of PPCs, the occurrence of postoperative extrapulmonary complications and all-cause mortality within the postoperative 7 and 30 days. Discussion: PROVIO trial assesses the effect of low versus high FiO₂ in lung-protective ventilation strategy on PPCs for abdominal surgery patients and the results will provide practical approaches to intraoperative oxygen management. Trial registration number: Registered at www.ChiCTR.org.cn on 13 February 2018 with identifier no. ChiCTR18 00014901.