open lung protective extubation following general anesthesia

Conditions: Intra-abdominal Surgery; Anesthesia; Lung Injury; Ventilator-Induced Lung Injury; Atelectasis

Summary: perioperative respiratory complications are a major source of morbidity and mortality. postoperative atelectasis plays a central role in their development. protective "open lung" mechanical ventilation aims to minimize the occurrence of atelectasis during the perioperative period. randomized controlled studies have been performed comparing various "open lung" ventilation protocols, but these studies report varying and conflicting effects. the interpretation of these studies is complicated by the absence of imagery supporting the pulmonary impact associated with the use of different ventilation strategies. imaging studies suggest that the gain in pulmonary gas content in "open lung" ventilation regimens disappears within minutes after the extubation. thus, the potential benefits of open-lung ventilation appear to be lost if, at the time of extubation, no measures are used to keep the lungs well aerated. recent expert recommendations on good mechanical ventilation practices in the operating room conclude that there is actually no quality study on extubation. extubation is a very common practice for anesthesiologists as part of their daily clinical practice. it is therefore imperative to generate evidence on good clinical practice during anesthetic emergence in order to potentially identify an effective extubation strategy to reduce postoperative pulmonary complications.

the aim of this study is to establish the feasibility of a multicenter randomized controlled clinical trial comparing two clinical strategies called "open lung" and "conventional" during extubation. the investigators also aim to estimate the rates of postoperative pulmonary complications in the two intervention groups. methods a multicenter internal pilot, prospective, randomized, allocation-concealed and controlled assessor-blinded study. two hundred sixteen patients scheduled to undergo elective intra-abdominal surgery requiring general anesthesia and planned hospitalization at four canadian hospitals, and at moderate or high risk of postoperative pulmonary complications according to the ariscat score will be recruited. following the administration of standardized mechanical ventilation and after obtaining consent, participants will be randomly assigned to two groups: group a: intervention group, "open lung" extubation strategy group b: control group, "conventional" extubation strategy. the rate of adherence to the extubation protocol, the weekly patient recrutement rate and the 7-day postoperative pulmonary complications outcome completion rate will be measured. we will only report secondary efficacy outcome in aggregate as they will be rolled over to the definitive trial.

Eligibility criteria:
inclusion criteria: * adult patients (18 years of age or over) * elective intra-abdominal surgery under general anesthesia. * moderate or high risk of postoperative pulmonary complication according to the ariscat score (score of 26 or more) * planned postoperative hospitalization exclusion criteria: * expected or known difficult intubation according to the treating anesthesiologist * postoperative mechanical ventilation (planned or unplanned) * general anesthesia performed outside the main operating room