Building Evidence in Perioperative Mechanical Ventilation––10 Years of Randomized Trials

The aims of this narrative review are to describe the evolution of randomized clinical trials (RCTs) assessing intraoperative mechanical ventilation strategies over the years and to summarize their key findings.

Over the past decade, numerous RCTs have investigated various intraoperative ventilation settings. A frequently utilized outcome measure in these studies has been the incidence of postoperative pulmonary complications (PPCs).

We conducted a PubMed search to evaluate the impact of intraoperative ventilation strategies on the occurrence of PPCs. We included only English language RCTs published within the last 10 years. To be eligible, PPCs had to be either the primary endpoint or a significant secondary endpoint. Studies involving pediatric patients or those undergoing thoracic of cardiac procedures were excluded. Studies indicate that the combination of high positive end–expiratory pressure (PEEP) and low tidal volumes protects patients against the development of PPCs. However, RCTs comparing only tidal volumes, only PEEP, only recruitment maneuvers (RMs), or only fractions of inspired oxygen, have not demonstrated differences in the incidence of PPCs. In recent years, there has been a shift towards individualized ventilation settings. Although individualized RMs have not improved outcomes, studies suggest that individualized PEEP could protect patients against the development of PPCs. Ongoing studies on the individualization of PEEP are expected to provide further clarity on this matter in the future.