Modified stress scores enhance prediction of outcomes after pediatric cardiac surgery

Perioperative hyperglycemia and metabolic stress are common in pediatric cardiac surgery and linked to adverse outcomes. The Glycemic Stress Index (GSI) has been proposed as a marker of intraoperative stress, but its predictive value remains limited. We hypothesized that modified stress scores incorporating additional clinical parameters would improve risk prediction.

We retrospectively analyzed 410 patients (1 month-18 years) undergoing open-heart surgery with cardiopulmonary bypass between 2015 and 2023. Patients with redo or emergency surgery, metabolic disorders, or preoperative hyperglycemia were excluded. GSI and three modified stress scores (MSS1, MSS2, and Final MSS) were calculated.

Metabolic uncoupling occurred in 6.6% of patients and was associated with higher stress scores and complications. Final MSS correlated most strongly with mechanical ventilation duration, PICU stay, and PRISM score. For mortality prediction, Final MSS demonstrated the highest discriminative ability (AUC 0.897), outperforming GSI and intermediate models. For complication prediction, Final MSS also showed the best performance (AUC 0.756).

Modified stress scores, particularly Final MSS, enhanced prediction of mortality and postoperative complications compared with the original GSI. These scores may serve as practical tools for early postoperative risk stratification in pediatric cardiac surgery.

This study demonstrates that modified stress scores, particularly Final MSS, provide superior predictive accuracy for mortality and complications after pediatric cardiac surgery compared to the original GSI. It introduces a novel, stepwise refinement of GSI by incorporating bypass time, inotrope requirements, and age adjustment, tailored for pediatric cardiac patients. The findings highlight the clinical utility of metabolic stress markers in risk stratification, offering an accessible tool for early identification of high-risk patients and potentially guiding perioperative management strategies.