Factors associated with renal oxygen extraction in mechanically ventilated children after the Norwood operation: insights from high fidelity hemodynamic data

Abstract

Background As the human body and its constituent organs require oxygen to function, maintaining the adequacy of systemic oxygen delivery is of utmost importance, particularly in critically ill children. Renal oxygen extraction can be utilized as a metric of the balance between systemic oxygen delivery and oxygen consumption. The primary aim of this study was to determine what clinical factors are associated with renal oxygen extraction in children with parallel circulation after the Norwood operation. Methods Mechanically ventilated children who underwent a Norwood operation from September 1, 2022 to March 1, 2023 were identified as these patients had data collected and stored with high fidelity by the T3 software. Data regarding hemodynamic values, fluid balance, and airway pressure were collected. These data were analyzed using Bayesian regression to determine the association of the individual metrics with renal oxygen extraction. Results A total of 27,270 datapoints were included in the final analyses. The resulting top two models explained had nearly 80% probability of being true and explained over 90% of the variance in renal oxygen extraction. Conclusion Increased milrinone, epinephrine, mean arterial pressure, and systemic blood flow were associated with decreased (improved) renal oxygen extraction while increased mean airway pressure, central venous pressure, arterial saturation by pulse oximetry, and systemic vascular resistance were associated with increased (worsened) renal oxygen extraction.