A prospective randomized clinical study of perioperative oral thyroid hormone treatment for children undergoing surgery for congenital heart diseases

Abstract

Context : Thyroid hormone deficiency is known to occur after cardiac surgery and known as nonthyroid illness (NTI). The beneficial role of perioperative thyroid hormone supplementation in children has been debatable more so with oral supplementation. Aims : The aim is to evaluate the role of pre-operative oral thyroid hormone therapy in preventing NTI. To assess its effect on post-operative thyroid hormone levels, hemodynamic parameters, and cardiac function of infants and small children undergoing pediatric cardiac surgery. Settings and Design : Prospective randomized, double-blinded controlled trial at a tertiary level pediatric cardiothoracic center. Materials and Methods : Sixty-five children aged under 18 months undergoing corrective surgeries on cardiopulmonary bypass were included. Patients were randomized into two equal groups: placebo group (given placebo) and thyroxine group (given thyroxine tablet 10 μg/kg) orally once a day starting on the preoperative evening till the fifth postoperative day. The postoperative hemodynamics, inotropic requirement, ventilatory requirement, and cardiac function on echocardiography were observed. Statistical Tests : Shapiro–Wilk test, Mann–Whitney/t-test, Chi-square test, ANOVA with Tukey correction were used. Results: Serum triiodothyronine and thyroxine levels postoperatively were significantly higher in the thyroxine group than in the placebo group. There was no significant difference in left ventricular ejection fraction, hemodynamic variables, extubation time, and length of intensive care unit (ICU) stay between the two groups. Conclusions: In infants and small children undergoing corrective cardiac surgery, perioperative oral thyroid hormone therapy reduces the severity of postoperative NTI. It increases the serum level of thyroid hormones but the therapy does not translate to better hemodynamics, reduced inotropic requirement, reduced ventilatory requirement, improved myocardial function or reduced ICU stay when compared to placebo.