Mechanical Power for Ventilatory Settings in Operating Room

Postoperative respiratory failure (PRF) is a dreaded complication that imposes a significant burden through unplanned admission to the ICU, post discharge disability and mortality. Despite widespread implementation of intraoperative lung-protective ventilation strategies over the past decade, results remain inconsistent. Interventions targeting individual parameters like tidal volume or positive end-expiratory pressure (PEEP) have shown equivocal results. The use of high PEEP and recruitment maneuvers raises safety concerns by possible negative hemodynamic effects. Recent studies suggest that individualizing ventilation strategies based on mechanical power-a composite parameter integrating tidal volume, plateau pressure, PEEP, and ventilator frequency-may better predict and help prevent PRF, independently of patients' baseline respiratory system compliance. These studies identified this parameter as interventional targets to reduce lung injury during mechanical ventilation. However, no multicenter randomized controlled trial has been performed in the field of ventilatory settings titration during invasive mechanical ventilation in operating room.

The investigators hypothesize that a ventilation strategy aimed at decreasing mechanical power will reduce the incidence of PRF and mortality in patients undergoing abdominal surgery, compared with a standard strategy using fixed tidal volume and PEEP