Reduction of Inflammation by High-Dose Methylprednisolone Does not Attenuate Oxidative Stress in Children Undergoing Bidirectional Glenn Procedure With or Without Aortic Arch or Pulmonary Arterial Repair

Abstract

Objective: Corticosteroids attenuate an inflammatory reaction in pediatric heart surgery. Inflammation is a source of free oxygen radicals. Children with a cyanotic heart defect are prone to increased radical stress during heart surgery. The authors hypothesized that high-dose methylprednisolone reduces inflammatory reaction and thereby also oxidative stress in infants with a univentricular heart defect undergoing the bidirectional Glenn procedure.

Design: A double-blind, placebo-controlled, randomized clinical trial.

Setting: Operating room and pediatric intensive care unit of a university hospital.

Participants: The study comprised 29 infants undergoing the bidirectional Glenn procedure with or without aortic arch or pulmonary arterial repair.

Interventions: After anesthesia induction, the patients received intravenously either 30 mg/kg of methylprednisolone (n = 15) or the same volume of saline as placebo (n = 14).

Measurements and main results: Plasma interleukin-6, interleukin-8, interleukin-10 (biomarkers of inflammation), and 8-hydroxydeoxyguanosine concentrations (a biomarker of oxidative stress) were measured at the following 4 time points: preoperatively, during cardiopulmonary bypass, after protamine administration, and 6 hours postoperatively. The study parameters did not differ between the study groups preoperatively. Methylprednisolone reduced the proinflammatory cytokines interleukin-6 and interleukin-8 and increased the anti-inflammatory cytokine interleukin-10 postoperatively. Despite reduced inflammation, there were no differences in 8-hydroxydeoxyguanosine between the methylprednisolone and placebo groups.

Conclusions: The proinflammatory reaction and increase in free radical stress were not interrelated during congenital heart surgery in cyanotic infants with a univentricular heart defect undergoing the bidirectional Glenn procedure. High-dose methylprednisolone was ineffective in attenuating free radical stress.

Keywords: bidirectional Glenn procedure; congenital heart defect; infant; inflammation; methylprednisolone; radical stress.