Anesthesia, Atelectasis, Intra-abdominal Surgery, Lung Injury, Ventilator-Induced Lung Injury
Conditions
Brief 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.
Detailed description
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.
Interventions
OTHERProtective "open-lung" extubation
Emergence using 50% FiO2, semi-sitting position with pressure support ventilation and preserved PEEP
Emergence using 100% FiO2, dorsal decubitus position with assistance or manual bag ventilation without PEEP
Sponsors
Centre hospitalier de l'Université de Montréal (CHUM)
CHU de Quebec-Universite Laval
The Ottawa Hospital
University Health Network, Toronto
Canadian Institutes of Health Research (CIHR)
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
DOUBLE (Subject, Outcomes Assessor)
Masking description
Until surgical closure, all will be blinded to treatment allocation. Only specific healthcare professionals (anesthesiologist, respiratory therapist, operating room nurses, unblinded research assistant) will be present during emergence to maintain blinding. Other healthcare team members will remain blinded. Outcome adjudicators, Executive and Steering committee members, and the data analyst will also be blinded. No mechanism for unblinding is planned, as both interventions follow the same diagnostic and treatment algorithms for adverse effects.
Intervention model description
During surgical closure, the definitive ARISCAT score and exclusion criteria will be assessed. Patients will be randomized equally (1:1) using web-based allocation-concealed methods, with stratification by center and ARISCAT risk category. An unblinded research assistant will reveal group allocation to the anesthesiologist and monitor the emergence procedure.
Eligibility
Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No
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
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Average weekly patient recruitment rate | Every week. At the end of the study (average 9 months) at the study level. | Achieve a weekly patient recruitment rate of 2 patients per week per center |
| Protocol adherence rate | At the end of surgery for individual assessments. At the end of the study (average 9 months) at the study level. | Assess adherence to a protocol during emergence from anesthesia, monitoring four criteria (proper positioning (dorsal decubitus or semi-sitting position), correct FiO2 (100% or 50%), appropriate ventilatory mode (manual or pressure support ventilation), and proper end-expiratory pressure (zero or preserved end-expiratory pressure), and noting deviations, with adherence defined as successful performance of all criteria during extubation. |
| Postoperative pulmonary complications outcome completion rate | At postoperative day 7 for individual assessments. At the end of the study (average 9 months) at the study level. | Postoperative pulmonary complications are defined as a composite endpoint that includes atelectasis, pneumonia, acute respiratory distress syndrome, and pulmonary aspiration, according to the StEP-COMPAC definition. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Accuracy of self-reported protocol adherence compared to directly observed protocol adherence | At the end of the surgery | Following emergence from general anesthesia, treating anesthesiologists will complete the same four-point scoring sheet as the research assistant to self-report protocol adherence. |
| Postoperative pulmonary complications | At postoperative day 7 | Postoperative pulmonary complications are defined as a composite endpoint that includes atelectasis, pneumonia, acute respiratory distress syndrome, and pulmonary aspiration, according to the StEP-COMPAC definition. |
| Amount of supplemental oxygen administered following discharge from the post-anesthesia care unit | At postoperative day 7 or hospital discharge (earliest of the two) | Obtained from the electronic medical record or the handwritten vital signs sheet. Calculated as %.h-1 |
| Quality of recovery | At postoperative day 1 | Evaluated using the QoR-15 questionnaire completed at the bedside. |
| Discharge disposition | At postoperative day 30 | Location to which patient is discharged (e.g., home, long term care facility, etc.) Assessed during telephone interview and using administrative data. We will |
| Days alive and out of hospital | At postoperative day 30 | Assessed during telephone interview and using administrative data |
| Health-related quality of life | At postoperative day 90 | Evaluated using the EQ-5D-5L questionnaire completed during a telephone interview |
Countries
Canada
Contacts
CONTACTMartin Girard, MD
CONTACTEva Amzallag, MSC
PRINCIPAL_INVESTIGATORMartin Girard, MD
Centre hospitalier de l'Université de Montréal (CHUM)
Outcome results
None listed