Effect of protective ventilation throughout the intubation period on perioperative oxygenation in patients undergoing MIDCABG: a randomised controlled trial.
INTRODUCTION: Minimally invasive direct coronary artery bypass grafting (MIDCABG) requires prolonged one-lung ventilation (OLV), increasing postoperative pulmonary complications (PPCs) risk. We investigated whether protective lung ventilation (PLV) throughout intubation benefits MIDCABG patients. METHODS: In this single-center randomized study, MIDCABG patients received PLV (low tidal volume of 6-8 mL·kg-1, PEEP of 6 cm H2O, alveolar recruitment maneuvers) or conventional mechanical ventilation (CMV, tidal volume of 8-10 mL·kg-1, without PEEP or maneuvers) from tracheal intubation to extubation. The primary outcome was perioperative oxygenation, assessed by the PaO2/FiO2 ratio. RESULTS: Sixty patients (n = 30 per group) were enrolled. Compared with CMV, PLV improved PaO2/FiO2 ratios (mean difference at OLV60: 34.56 mmHg; 95% CI: 11.78-57.33; p < 0.01), shortened median durations of postoperative mechanical ventilation (median difference: -4.5 h, 95% CI: -8.5 to -0.5; p = 0.013) and hospital stay (median difference: -3.0 days, 95% CI: -5.0 to -1.0; p = 0.019). PLV also reduced driving pressure, airway pressure and intrapulmonary shunt during OLV (all p < 0.05). Desaturation occurred in 23.3% of CMV patients and 13.3% of PLV patients (p = 0.506). Hemodynamic parameters were generally comparable between groups, except for lower MPAP and PVRI in the PLV group during OLV and after ICU admission (p < 0.05). The incidence of PPCs did not differ between groups. CONCLUSIONS: In patients undergoing MIDCABG, PLV applied throughout intubation improved perioperative oxygenation and shortened the duration of postoperative mechanical ventilation and hospital stay, but did not reduce PPCs. CLINICAL TRIAL REGISTRATION: ChiCTR1900022005.