A phase III, multicenter randomized controlled trial found that a perioperative lung expansion bundle may not significantly reduce the severity of postoperative pulmonary complications in patients undergoing major open abdominal surgery compared with usual care.
In the PRIME-AIR trial, published in The Lancet Respiratory Medicine, researchers randomly assigned 751 patients across 17 U.S. academic hospitals to either the intervention bundle (n = 379) or usual care (n = 372).
The intervention included preoperative education, intraoperative individualized positive end-expiratory pressure (PEEP) titration, neuromuscular blockade administration and reversal, and postoperative supervised incentive spirometry with early ambulation. Despite high adherence (72% to 98%), postoperative pulmonary complication (PPC) severity did not significantly differ between the groups, with mean severity grades of 1.60 (standard deviation [SD] = 0.94) in the intervention group and 1.53 (SD = 0.93) in usual care (mean difference = 0.07, 95% confidence interval [CI] = –0.03 to 0.18, P = .19). The most common PPC severity was grade 2 (56% vs 60%), while grades 3 to 4 PPCs were more frequent in the intervention group (12% vs 8%, P = .03).
Patients in the intervention group received higher mean PEEP (7.5 cmH2O [SD = 2.5] vs 5.6 cmH2O [SD = 1.4]) and more frequent neuromuscular blockade reversal (86% vs 70%) compared with usual care. While the intervention did not improve PPC outcomes, it significantly reduced intraoperative respiratory rescue interventions (2% vs 6%, RR = 0.3, 95% CI = 0.1–0.7, P = .004).
Mortality rates remained low and comparable between groups: at 7 days (< 1% vs 1%), 30 days (< 1% vs 1%), and 90 days (2% vs 1%).
"Our results imply a plateau in the benefits of open-lung approaches for the general population of patients undergoing major abdominal surgery," said lead study author Ana Fernandez-Bustamante, PhD, of the Department of Anesthesiology at the University of Colorado School of Medicine, and colleagues.
However, the intraoperative personalized PEEP-setting strategy may help manage intraoperative respiratory dysfunction by reducing the need for rescue maneuvers without causing hemodynamic adverse effects.
The study was funded by the U.S. National Institutes of Health National Heart, Lung, and Blood Institute. No conflicts of interest were disclosed.