Association between driving pressure and postoperative pulmonary complications in patients undergoing lung resection surgery: A randomised clinical trial

It is uncertain whether an association exists for decreases in driving pressure and the occurrence of postoperative pulmonary complications (PPCs) in patients undergoing selective lung resection surgery. Thus, we designed this study to determine whether the positive end-expiratory pressure (PEEP) titration to the lowest driving pressure compared with conventional low PEEP level during one-lung ventilation (OLV) in patients undergoing selective lung resection surgery decreases PPCs.This single-centre, randomised trial approved by the Ethical Committee of the Sun Yat-Sen University Cancer Center involved patients who signed written consent. Patients were randomised to the PEEP titration to the lowest driving pressure group (n = 104), or to the conventional low level of PEEP group (n = 103), consisting a PEEP level of 4 cm H2O during OLV. All patients received volume-controlled ventilation with a tidal volume of 6 mL/kg of predicted body weight. The primary outcome was defined as positive if 4 or more of eight Melbourne Group Scale (MGS) variables developed within the first 3 days after surgery. The incidence of major PPCs occurring during postoperative 7 days was also recorded.Among 222 patients who were randomised, 207 (93%) completed the trial (109 men [53%]; mean age, 56.9 years). The primary outcome occurred in 4 of 104 patients (4%) in the PEEP titration to the lowest driving pressure group compared with 13 of 103 patients (13%) in the conventional low level of PEEP group (risk ratio, 0.32 [95% CI, 0.10-0.90]; P = 0.021).Among patients undergoing selective lung surgery, intraoperative OLV with PEEP titration to the lowest driving pressure compared with conventional low PEEP level (4 cm H2O) significantly reduced PPCs within the first 3 postoperative days, however, did not significantly reduce PPCs within the first 7 postoperative days.