Performance of Carbon Dioxide (CO2)-Derived Parameters in Predicting Low Cardiac Output Syndrome (GAP-CO2)

September 2, 2026 updated by: University Hospital, Lille

Performance of CO2-derived Parameters in Predicting Low Cardiac Output Syndrome in Children After Cardiac Surgery With Cardiopulmonary Bypass

In congenital cardiac intensive care, low cardiac output syndrome (LCOS) after surgery is defined by a decrease in cardiac output due to cardiac dysfunction. This syndrome is responsible for postoperative mortality and morbidity, as well as prolonged hospitalization.

carbon dioxide (CO2)-derived parameters are increasingly used to identify low cardiac output status by the venous-to-arterial carbon dioxide difference (PCO2 gap), or anaerobic metabolism by the venous-to-arterial carbon dioxide difference to arterial-to-venous oxygen content difference (Pv-aCO2/Ca-vO2) ratio, particularly in septic shock in adults, with or without hypoxemia. The thresholds proposed as pathological values were a PCO2 gap ≥ 6 mmHg and a Pv-aCO2/Ca-vO2 ratio ≥ 1.4 mmHg/ml. However, these markers have not been studied in depth in patients who have undergone cardiac surgery. In adults, studies have focused on the predictive value of the PCO2 gap and Pv-aCO2/Ca-vO2 on postoperative complications. In the pediatric population following cardiac surgery, only retrospective studies exist, with conflicting results on the correlation between the PCO2 gap and cardiac output, and the PCO2 gap and duration of mechanical ventilation.

This study aims to compare the performance of CO2-derived parameters in predicting LCOS and anaerobic metabolism in children after cardiac surgery with cardiopulmonary bypass.

Study Overview

Status

Recruiting

Conditions

Low Cardiac Output Syndrome Bypass Children

Study Type

Observational

Enrollment (Estimated)

306

Contacts and Locations

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

Study Contact

Name: Celine CLAIRET-LESPINASSE
Phone Number: +33 3204441145
Email: celine.clairet@chu-lille.fr

Study Contact Backup

Name: DRS. Promotion
Phone Number: +33 3204441145
Email: drs.promotion@chu-lille.fr

Study Locations

France
- - Lille, France
    - Recruiting
    - CHU Lille
    - Contact:
      
      Celine CLAIRET-LESPINASSE
      
      Phone Number: +33320444145
      
      Email: celine.clairet@chu-lille.fr
    - Principal Investigator:
      
      Morgan RECHER, Doctor

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

Child

Accepts Healthy Volunteers

Sampling Method

Non-Probability Sample

Study Population

Children after cardiac surgery with cardiopulmonary bypass (CPB)

Description

Inclusion Criteria:

Children under the age of 18
Post-operative cardiac surgery
Surgery with extracorporeal circulation
With a central venous catheter and an arterial catheter
Admitted to the pediatric intensive care unit at Lille University Hospital
Patient covered by the social security system (or equivalent)

Exclusion Criteria:

Pre-existing renal insufficiency prior to cardiac surgery
Opposition from the holder of parental authority
Difficulty understanding or communicating, making it impossible to inform the holder of parental authority
Patient under legal protection (guardianship, curatorship, legal safeguard)
Malposition of the central venous catheter
Malposition of the arterial catheter
Biological samples that cannot be interpreted

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

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
Receiver Operating Characteristic (ROC) curve of PCO2 gap Time Frame: 2 hours	2 hours

Secondary Outcome Measures

Outcome Measure	Time Frame
ROC curve of Pv-aCO2/Ca-vO2 Time Frame: 2 hours	2 hours
Pv-aCO2/Ca-vO2 and post-operatory complications Time Frame: 48 hours	48 hours

Collaborators and Investigators

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

Sponsor

University Hospital, Lille

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)

June 27, 2026

Primary Completion (Estimated)

June 27, 2029

Study Completion (Estimated)

July 1, 2029

Study Registration Dates

First Submitted

August 12, 2026

First Submitted That Met QC Criteria