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

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. A double-blind, placebo-controlled, randomized clinical trial. Operating room and pediatric intensive care unit of a university hospital. The study comprised 29 infants undergoing the bidirectional Glenn procedure with or without aortic arch or pulmonary arterial repair. 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). 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. 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.