Journal Article

Veno-arterial CO 2 content gradient and veno-arterial CO 2 to arterial-venous O 2 content ratio for outcome prediction after pediatric cardiac surgery: a prospective study

Beghetti, Maurice, Jaksic, Cyril, Nalecz, Tomasz, Sologashvili, Tornike, Cousin, Vladimir L, Wacker, Julie, Polito, Angelo, Joye, Raphael

2025

Overview

CO -derived variables, veno-arterial CO content gradient (ΔCCO ) and the ratio of ΔCCO with arterio-venous oxygen difference (AV-DO ) (ΔCCO2/AV-DO ), may have a potential role as indicators of low cardiac output and anaerobic metabolism, respectively. We sought to describe and evaluate the association of CO -derived variables with patients' outcomes in the post cardiopulmonary bypass (CPB) period in children. Prospective, single-center, study enrolling children post-CPB with paired arterial and venous blood gases for determination of lactate, O extraction, ΔCCO , and ΔCCO /AV-DO at admission (H0), and at 6 (H6), 12 (H12) and 24 (H24) hours. Different clinical patterns were defined based on the presence of an anaerobic context or a hypoperfusion context, using both O and CO -derived variables. The presence of anaerobic metabolism was defined with a lactate > 2 mmol/l and ΔCCO /AV-DO  > 1.8; the presence of hypoperfusion was defined with an O extraction > 30% and ΔCCO  > 6 mL. The potential association of duration of amine support and mechanical ventilation was tested with CO -derived variables and specific clinical patterns. A total of 51 patients with a median age of 36 (IQR 11-85) months were included. Median admission ΔCCO was 9.3 mL (IQR 5.6-11.4) with 72% above 6 mL. Median ΔCCO /AV-DO was 2.1 (IQR 1.5-2.4) with 58% above 1.8. Admission ΔCCO showed a significant association with the duration of mechanical ventilation (R2 21.6, p value = 0.001) but not with the duration of vasoactive support. Neither H0 ΔCCO nor H0 ΔCCO /AV-DO improved outcome prediction by a model including lactate and O extraction. Anaerobic metabolism context showed a significant association with prolonged vasoactive support [28.4 (CI 95% 12.2-44.6) p = 0.001] and mechanical ventilation duration [1.4 (95% CI 0.62-2.3) p = 0.003]. In hypoperfusion context, neither duration of vasoactive support nor mechanical ventilation appeared different in the subgroups analysis. CO -derived variables may improve outcome prediction after cardiac surgery in pediatric patients. Further evaluation in larger multicentered trials is necessary to improve its validation.