Protective mechanical ventilation with optimal PEEP during RARP improves oxygenation and pulmonary indexes

Abstract

Background: This trial aimed to evaluate the effects of a protective ventilation strategy on oxygenation/pulmonary indexes in patients undergoing robot-assisted radical prostatectomy (RARP) in the steep Trendelenburg position. Methods: In phase 1, the most optimal positive end-expiratory pressure (PEEP) was determined in 25 patients at 11 cmH2O. In phase 2, 64 patients were randomized to the traditional ventilation group with tidal volume (VT) of 9 ml/kg of predicted body weight (PBW) and the protective ventilation group with VT of 7 ml/kg of PBW with optimal PEEP and recruitment maneuvers (RMs). The primary endpoint was the intraoperative and postoperative PaO2/FiO2. The secondary endpoints were the PaCO2, SpO2, modified clinical pulmonary infection score (mCPIS), and the rate of complications in the postoperative period. Results: Compared with controls, PaO2/FiO2 in the protective group increased after the second RM (P=0.018), and the difference remained until postoperative day 3 (P=0.043). PaCO2 showed transient accumulation in the protective group after the first RM (T2), but this phenomenon disappeared with time. SpO2 in the protective group was significantly higher during the first three postoperative days. Lung compliance was significantly improved after the second RM in the protective group (P=0.025). The mCPIS was lower in the protective group on postoperative day 3 (0.59 (1.09) vs. 1.46 (1.27), P=0.010). Conclusion: A protective ventilation strategy with lower VT combined with optimal PEEP and RMs could improve oxygenation and reduce mCPIS in patients undergoing RARP. Trial registration: ChiCTR ChiCTR1800015626. Registered on 12 April 2018.