Effects of Intravenous Dexamethasone on IL-6 Levels in Children Undergoing Cardiac Surgery With Cardiopulmonary Bypass

Background: Cardiopulmonary bypass provokes a systemic inflammatory response in children, with interleukin-6 (IL-6) levels rising rapidly after bypass.Corticosteroids are frequently used to blunt this response, but paediatric evidence remains inconsistent.Objective: To evaluate whether a single intravenous dose of dexamethasone reduces the post-bypass increase in plasma IL-6 and improves early postoperative outcomes in children undergoing cardiac surgery with cardiopulmonary bypass.Methods: This single-centre quasi-experimental study enrolled 46 children aged one month to 12 years undergoing elective repair of congenital heart disease between January 2025 and August 2025.Participants were purposively recruited and alternately allocated to intravenous dexamethasone (1 mg/kg, maximum 10 mg; n=23, 50.0%) or 2 mL normal saline (n=23, 50.0%) after induction of anaesthesia.Plasma IL-6 was measured before drug administration, two hours after cardiopulmonary bypass, and 24 hours after bypass.Haemodynamic variables, oxygen saturation, extubation time, and intensive care unit stay were recorded.Results: The median IL-6 increase from baseline to two hours was lower with dexamethasone than with saline (261.90 pg/mL, interquartile range: 195.0-824.0,versus 447.0 pg/mL, interquartile range: 261.70-1,230.20),but the difference was not statistically significant (p=0.177).At 24 hours, the median change from baseline was 8.20 pg/mL in the dexamethasone group and 13.0 pg/mL in the saline group (p=0.350).Blood pressure, oxygen saturation, and extubation time were comparable.First-postoperative-day heart rate was higher with dexamethasone (143.63 ± 18.93 versus 117.76 ± 19.57beats/min; p=0.001), and median intensive care unit stay was longer (120 versus 95.5 hours; p=0.001).Conclusions: A single dose of intravenous dexamethasone at 1 mg/kg, capped at 10 mg, did not significantly attenuate the IL-6 response after paediatric cardiopulmonary bypass.The higher heart rate and longer intensive care stay observed in the dexamethasone group should be treated as exploratory because allocation was nonrandom and perioperative complexity was not adjusted for.