Intraoperative Hypocapnia in PROVHILO and PROBESE (iHypoPRO)

May 2, 2023 updated by: Prashant Nasa, NMC Specialty Hospital

Associations of Intraoperative Hypocapnia With Patient Demographics, Ventilation Characteristics and Outcomes--Statistical Analysis Plan for an Individual Patient Data Analysis of PROVHILO and PROBESE

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).

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Detailed Description

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.

Study Type

Observational

Enrollment (Actual)

2793

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • Brazil
      • São Paulo, Brazil
        • Hospital Israelita Albert Einstein
  • Germany
      • Dresden, Germany
        • University Hospital Carl Gustav Carus, Technische Universität Dresden
  • Italy
      • Genoa, Italy
        • IRCCS San Martino Policlinico Hospital
  • Spain
      • Barcelona, Spain
        • Hospital Clinic de Barcelona

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

18 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

No

Sampling Method

Non-Probability Sample

Study Population

Adult patients undergoing mechanical ventilation for general anesthesia for surgery.

Description

Inclusion Criteria:

  • Planned for major (abdominal) surgery.
  • At risk for postoperative pulmonary complications.

Exclusion Criteria:

  • Planned thoracic surgery or neurosurgery.
  • Unscheduled surgery (i.e., urgent, or emergent surgeries) were excluded because these patients may have had metabolic abnormalities at the moment of surgery, i.e., metabolic acidosis, for which the anesthesiologist may have adjusted the intraoperative ventilator settings. This may have led to a 'compensatory' low etCO2.
  • Patients with etCO2 recordings are missing from the study databases.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Observational Models: Cohort
  • Time Perspectives: Prospective

Cohorts and Interventions

Group / Cohort
Intervention / Treatment
with hypocapnia
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)
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.
without hypocapnia
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.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Incidence of postoperative pulmonary complications
Time Frame: Until day seven or hospital discharge, whichever comes first
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.
Until day seven or hospital discharge, whichever comes first

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Incidence of intraoperative complications
Time Frame: Intraoperatively
Defined as intraoperative hypotension, arrhythmias; or need for rescue for desaturations; or need for vasoactive drugs.
Intraoperatively
Incidence of intensive care unit admission
Time Frame: Until hospital discharge, death or 100 days, whichever comes first
Incidence of intensive care unit admission during hospital stay
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
Until day seven or hospital discharge, whichever comes first
Incidence of 7-day mortality
Time Frame: Mortality during the first seven days of hospitalization
Until day seven or hospital discharge, whichever comes first
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
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
Time Frame: Until day seven or hospital discharge, whichever comes first
Collapsed composite of complications developing within the first seven postoperative combining severe postoperative pulmonary complications, sepsis, septic shock and/or acute kidney injury
Until day seven or hospital discharge, whichever comes first

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

NMC Specialty Hospital

Collaborators

Academisch Medisch Centrum - Universiteit van Amsterdam (AMC-UvA)
Hospital Israelita Albert Einstein
University Hospital Carl Gustav Carus
Hospital Clínico Universitario de Valencia

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

November 29, 2022

Primary Completion (Actual)

January 10, 2023

Study Completion (Actual)

March 31, 2023

Study Registration Dates

First Submitted

September 17, 2022

First Submitted That Met QC Criteria

September 21, 2022

First Posted (Actual)

September 22, 2022

Study Record Updates

Last Update Posted (Estimate)

May 4, 2023

Last Update Submitted That Met QC Criteria

May 2, 2023

Last Verified

May 1, 2023

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • AUMC

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

YES

IPD Plan Description

The harmonized dataset will be available after the publication of the main results and under request to the steering committee

IPD Sharing Time Frame

After the publication of the main results

IPD Sharing Supporting Information Type

  • STUDY_PROTOCOL
  • SAP
  • ANALYTIC_CODE
  • CSR

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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