Performance of CO2-derived Parameters in Predicting Low Cardiac Output Syndrome

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.

CO2-derived parameters are increasingly used to identify low cardiac output status by the PCO2 gap, or anaerobic metabolism by the 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.

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