Neuroprotective Effects of Dexmedetomidine in Pediatric Open-heart Surgery with Cardiopulmonary Bypass: A Randomized Controlled Study Using Near-Infrared Spectroscopy and S-100B

Cardiopulmonary Bypass (CPB) during pediatric congenital heart surgery is associated with a risk of perioperative neurological injury. This study aimed to evaluate whether intra-CPB administration of dexmedetomidine reduces neuronal injury, as assessed by serum S-100B levels and regional cerebral oxygen saturation (rSO₂) monitored with near-infrared spectroscopy (NIRS).

This double-blind randomized controlled trial included 32 children aged 0–18 years undergoing open-heart surgery with CPB. Patients were randomized to receive either dexmedetomidine or placebo, with 16 patients in each group. In the dexmedetomidine group, 0.5 µg/kg dexmedetomidine was added to the CPB priming solution, followed by a continuous infusion of 0.25 µg/kg/h into the CPB reservoir during bypass. Serum S-100B levels were measured before CPB and 6–12 hours postoperatively. Cerebral rSO₂ was monitored at predefined perioperative time points. Secondary outcomes included duration of mechanical ventilation, cardiac intensive care unit length of stay, and 7-day mortality.

Baseline pre-CPB S-100B levels did not differ significantly between the control and dexmedetomidine groups [8.76 (3.04–14.70) vs. 11.89 (3.93–14.20) pg/mL; p = 0.127]. Post-CPB S-100B levels were significantly higher in the control group than in the dexmedetomidine group (33.97 vs. 9.39 pg/mL; p = 0.019). The change in S-100B levels also differed significantly between groups, with an increase in the control group and a decrease in the dexmedetomidine group (+14.62 vs. −4.53 pg/mL; p = 0.001). Cerebral rSO₂ showed similar temporal trends in both groups, with no statistically significant between-group differences at any measurement time point. Duration of mechanical ventilation, cardiac intensive care unit length of stay, and 7-day mortality were comparable between groups.

Intra-CPB dexmedetomidine was associated with lower postoperative S-100B levels, suggesting a potential reduction in biochemical evidence of neuronal injury during pediatric cardiac surgery with CPB. However, this biochemical effect was not accompanied by measurable differences in cerebral oxygenation or short-term clinical outcomes, indicating that its clinical significance remains uncertain.

Intra-CPB dexmedetomidine administration was associated with lower postoperative S-100B levels in pediatric patients undergoing open-heart surgery with CPB. Larger studies incorporating serial biomarker measurements and long-term neurodevelopmental follow-up are warranted to determine whether this biochemical effect translates into clinically meaningful neuroprotection.

TCTR20260317004