Pulmonary complications with individualised vs. fixed positive end-expiratory pressure in older patients recovering from lung cancer surgery: a randomised trial.

Abstract

Postoperative pulmonary complications are common after lung cancer surgery in older adults. Individualised positive end-expiratory pressure may optimise intra-operative lung mechanics, but its effect on postoperative pulmonary complications is uncertain. We hypothesised that individualised positive end-expiratory pressure would reduce the incidence of postoperative pulmonary complications compared with a fixed positive end-expiratory pressure in older patients (age ≥ 60 years) undergoing lung cancer surgery. In total, 400 patients were allocated randomly to individualised positive end-expiratory pressure (PEEP_IND group) or a fixed positive end-expiratory pressure of 5 cmH₂O (PEEP₅ group). The primary outcome was the incidence of postoperative pulmonary complications. Secondary outcomes included duration of postoperative hospital stay; extrapulmonary complications; 30-day postoperative complications; driving pressure; and oxygenation index. Median (IQR [range]) individualised positive end-expiratory pressure was 11 (9-11 [3-13]) cmH₂O during one-lung and 9 (7-9 [3-13]) cmH₂O during two-lung ventilation. Patients allocated to the PEEP_IND group had lower driving pressures during one-lung (12 (11-14 [4-23]) vs. 15 (13-18 [7-24]) cmH₂O, p < 0.001) and two-lung ventilation (9 (7-13 [4-26]) vs. 12 (10-14 [5-26]) cmH₂O, p < 0.001) and a higher oxygenation index during one-lung ventilation (26.7 (20.3-34.4 [6.7-55.9]) vs. 22.7 (16.0-29.3 [8.8-58.9]) kPa, p < 0.001) compared with those allocated to the PEEP₅ group. Despite this, the incidence of postoperative pulmonary complications was similar between groups (PEEP_IND group 54/195 (28%) vs. PEEP₅ group 50/197 (25%), risk ratio 1.09, 95%CI 0.79-1.52, p = 0.60). Electrical impedance tomography-guided individualised positive end-expiratory pressure reduced driving pressures and improved intra-operative oxygenation but did not decrease the incidence of postoperative pulmonary complications in older adults undergoing lung cancer surgery.