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

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.

Inclusion criteria

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

Non-inclusion criteria :

• Heart transplant patients
• Patients who have received long-term cardiac assistance
• Minor patients