An observational study in Mechanical Ventilation Complication, Surgery and Pulmonary Complication, sponsored by NMC Specialty Hospital. Completed at 4 sites in 4 countries. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2023-05-06.
Sponsored by NMC Specialty Hospital · Observational
To gain a better understanding of the epidemiology of intraoperative hypocapnia, in particular the associations of intraoperative hypocapnia with patient demographics, ventilator characteristics, and perioperative complications we will perform an individual patient-level meta-analysis of two recent randomized clinical trials of intraoperative ventilation, the 'PROtective Ventilation using High versus LOw PEEP trial' (PROVHILO), and the 'Protective intraoperative ventilation with higher versus lower levels of positive end-expiratory pressure in obese patients trial' (PROBESE).
Lung-protective intraoperative ventilation (LPV) has the potential to improve the outcome of surgery patients through a reduction in postoperative pulmonary complications. Use of intraoperative ventilation strategies that use a low tidal volume could result in intraoperative hypercapnia. However, hypocapnia remains surprisingly common during intraoperative ventilation, possibly meaning that anesthesiologists continue to use high, if not too high respiratory rates or tidal volumes.
Previous studies suggested associations between intraoperative derangement of end-tidal carbon dioxide (etCO2) and postoperative outcomes. Indeed, two studies in highly selected patient groups showed associations of intraoperative hypocapnia with prolonged length of hospital stay, in patients undergoing pancreaticoduodenectomy, and in patients undergoing hysterectomy.
To gain a better understanding of the epidemiology of intraoperative hypocapnia, in particular the associations of intraoperative hypocapnia with patient demographics, ventilator characteristics, and perioperative complications we will perform an individual patient-level meta-analysis of two recent randomized clinical trials of intraoperative ventilation; PROVHILO and PROBESE.
1,233 studies on the registry are indexed under Postoperative Complications; 292 are open to participants now.
This study's enrollment of 2,793 is above the median of 254 across 519 observational studies indexed under Postoperative Complications.
Browse Postoperative Complications studies →NMC Specialty Hospital is the lead sponsor of 9 studies on the registry; none are open to participants now.
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Adult patients undergoing mechanical ventilation for general anesthesia for surgery.
Exclusion Criteria:
We will use the intraoperatively collected etCO2 levels to classify patients as either 'with hypocapnia' or 'without hypercapnia', using the cutoff of 35 mmHg. A patient is considered 'hypocapnic' if the etCO2 was \< 35 mm Hg at any point during surgery, from start of the study till end of the study
Behavioral: intraoperative mechanical ventilation with hypocapnia (etCO2 < 35 mm Hg)
We will use the intraoperatively collected etCO2 levels to classify patients as either 'with hypocapnia' or 'without hypercapnia', using the cutoff of 35 mmHg. A patient is considered 'hypocapnic' if the etCO2 was \< 35 mm Hg at any point during surgery, from start of the study till end of the study, and classified as 'without hypocapnia' otherwise. In case of a missing value immediately before extubation, we will use the values as reported in the last hour of surgery.
A patient is considered 'hypocapnic' if the etCO2 was \< 35 mm Hg at any point during surgery, from start of the study till end of the study and classified as 'without hypocapnia' otherwise. In case of a missing value immediately before extubation, we will use the values as reported in the last hour of surgery.
Incidence of postoperative pulmonary complications
Composite of predefined and collected postoperative pulmonary complications. Postoperative pulmonary complications included mild, moderate, and severe respiratory failure; acute respiratory distress syndrome; bronchospasm; new pulmonary infiltrate; pulmonary infection; aspiration pneumonitis; pleural effusions; atelectasis; cardiopulmonary edema; and pneumothorax.
Time frame: Until day seven or hospital discharge, whichever comes first
Incidence of intraoperative complications
Defined as intraoperative hypotension, arrhythmias; or need for rescue for desaturations; or need for vasoactive drugs.
Time frame: Intraoperatively
Incidence of intensive care unit admission
Incidence of intensive care unit admission during hospital stay
Time frame: Until hospital discharge, death or 100 days, whichever comes first
Incidence of extrapulmonary pulmonary complications
Time frame: Until day seven or hospital discharge, whichever comes first
Incidence of 7-day mortality
Until day seven or hospital discharge, whichever comes first
Time frame: Mortality during the first seven days of hospitalization
Incidence of in-hospital mortality
Time frame: From date of randomization until the date of first documented progression or date of death from any cause, whichever came first, assessed up to 100 days
Incidence of major postoperative complications
Collapsed composite of complications developing within the first seven postoperative combining severe postoperative pulmonary complications, sepsis, septic shock and/or acute kidney injury
Time frame: Until day seven or hospital discharge, whichever comes first
Documents are hosted by the registry — open the source record to download them.
Plan to share: Yes — The harmonized dataset will be available after the publication of the main results and under request to the steering committee
Supporting information: Study protocol, Sap, Csr, Analytic code
This study is completed, as verified in May 2023. You cannot join it, but the record below documents what was studied.
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NMC Specialty Hospital