Pronostic Value of Gap CO2 During Cardiac Pulmonary Bypass in Cardiac Surgery: a Multicenter Retrospective Study (CO2-CARD)

Étude rétrospective de la Valeur Pronostique du pCO2 Gap Durant la Circulation Extracorporelle en Chirurgie Cardiaque

Cardiac surgery associated acute kidney injury (CSA-AKI) is one of the most frequent and severe complications after cardiac surgery. The association between acute kidney injury and the mismatch between oxygen consumption and delivery has been well established during cardiopulmonary bypass (CPB) and contributes to the development of CSA-AKI. In this study, the investigators aim to explore the use of gap CO2 during cardiac surgery and its relation with CSA-AKI. In order to explore this association, the invetigators built a retrospective, multicentric study. All patient who underwent cardiac surgery with cardiopulmonary bypass in two French ICU between 03/2019 and 04/2023 and for which information about gap CO2 during CPB is available will be included. After inclusion, patient will be divided in two groups according to the presence or absence of an elevated gap CO2. Occurence of CSA-AKI and other outcomes will be compared between groups, using multivariate analysis.

Study Overview

• Status: Completed
• Conditions: Cardiac Surgery Associated Kidney Injury

Detailed Description

Cardiac surgery associated acute kidney injury (CSA-AKI) is one of the most frequent and severe complications after cardiac surgery. The association between acute kidney injury and the mismatch between oxygen consumption and delivery has been well established during cardiopulmonary bypass (CPB) and contributes to the development of CSA-AKI. In order to explore this association, investigators build a retrospective study including all patients who underwent cardiac surgery requiring CPB in two French hospitals and for which data about gap CO2 during CPB is available. Patients will be divided into two groups according to the presence or absence of an elevated gap CO2 during CPB, defined as > 6 mmHg. The primary outcome is the occurrence of CSA-AKI, defined by KDIGO recommendations, according gap CO2. Secondary outcomes include others post-operative complications as defined by international guidelines. Performance of gap CO2 to predict CSA-AKI will be evaluated by calculating the Area Under the Curve (AUC) of the associated ROC curve. We'll also assess the correlation between gap CO2 and other perfusion parameters (lactate, svO2) and with mean DO2 during CPB.

• Study Type: Observational
• Enrollment (Actual): 318

Contacts and Locations

Study Locations

• France
  • Paris, France, 75571
    • Service d'Anesthésie Réanimation, Hôpital de la Pitié-Salpêtrière
  • Rennes, France
    • Service d'Anesthésie-Réanimation, Hôpital Pontchaillou, Rennes

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

• Sampling Method: Non-Probability Sample

Study Population

Patients older than 18, which underwent cardiac surgery with cardiopulmonary bypass

Description

Inclusion criteria:

1. Informed patients who did not object to the use of their data in the study.
2. Patients undergoing cardiac surgery with extracorporeal circulation.
3. Patients for whom a pCO2 gap measurement is available during ECG.

Non-inclusion criteria :

1. Heart transplant patients
2. Patients who have received long-term cardiac assistance
3. Minor patients

Study Plan

How is the study designed?

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort
elevated gap CO2 group and low gap CO2 group; Gap CO2 is calculated as PvCO2-PaCO2, using arterial and venous blood gases taken during CPB. Patients will be included in the elevated gap CO2 group when gap CO2 during CPB is > 6 mmHg

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Acute Kidney Injury	proportion of patient with acute kidney injury of Acute Kidney Injury as defined in the KDIGO guidelines within the first 7 days after the cardiac surgery	within the 7 days after surgery

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Mortality, occurrence of other complications	proportion of patient with others post-operative complications as defined by international post-operative guidelines: atrial fibrillation, ARDS , VA-ECMO implantation, cardiac arrest, length of stay in ICU and hospital and the mortality rate within the first 28 days	within the 28 days after surgery

Collaborators and Investigators

• Sponsor: Assistance Publique - Hôpitaux de Paris

Study record dates

Study Major Dates

• Study Start (Actual): February 27, 2025
• Primary Completion (Actual): April 4, 2025
• Study Completion (Actual): April 4, 2025

Study Registration Dates

• First Submitted: November 8, 2024
• First Submitted That Met QC Criteria: November 26, 2024
• First Posted (Actual): November 29, 2024

Study Record Updates

• Last Update Posted (Actual): April 24, 2025
• Last Update Submitted That Met QC Criteria: April 22, 2025
• Last Verified: April 1, 2025

More Information

Terms related to this study

• Keywords: Cardiac surgery; Cardiopulmonary bypass; AKI
• Other Study ID Numbers: APHP241392

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES

IPD Plan Description

The procedures carried out with the French data privacy authority (CNIL, Commission nationale de l'informatique et des libertés) do not provide for the transmission of the database, nor do the information and consent documents signed by the patients.

Consultation by the editorial board or interested researchers of individual participant data that underlie the results reported in the article after deidentification may nevertheless be considered, subject to prior determination of the terms and conditions of such consultation and in respect for compliance with the applicable regulations.

• IPD Sharing Time Frame: Beginning 3 months and ending 3 years following article publication. Requests out of these time frame can also be submitted to the sponsor
• IPD Sharing Access Criteria: Researchers who provide a methodologically sound proposal.
• IPD Sharing Supporting Information Type: STUDY_PROTOCOL

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No