Thyroid hormone supplementation for the prevention of morbidity and mortality in infants undergoing cardiac surgery

• Published in: Cochrane database of systematic reviews 2004 (3), p.CD004220-CD004220
• Main Authors: Dimmick, S, Badawi, N, Randell, T
• Format: Article
• Language: English
• Subjects: Humans; Infant; Infant, Newborn; Randomized Controlled Trials as Topic; Thoracic Surgical Procedures; Thyroid Hormones - administration & dosage; Thyroid Hormones - adverse effects; Thyroid Hormones - blood; Triiodothyronine - administration & dosage
• ISSN: 1469-493X

Paediatric studies have demonstrated that cardiopulmonary bypass is associated with a decline in thyroid hormone levels. Adult patients who undergo open heart surgery and receive triiodothyronine supplementation have demonstrated a dose-dependent increase in cardiac output which has been associated with an improved clinical outcome. Thyroid hormone supplementation in infants may also reduce post-operative morbidity and mortality. To determine if peri-operative thyroid hormone supplementation or replacement in infants undergoing cardiac surgery on cardiopulmonary bypass improves post-operative and longer term morbidity and mortality. The standard search strategy of the Cochrane Neonatal Review Group was used. This included searches of The Oxford Database of Perinatal Trials, MEDLINE (1966 - December 2003), EMBASE (1980 - December 2003), CINAHL (1982 - December 2003), The Cochrane Central Register of Controlled Trials (The Cochrane Library, Issue 2, 2003), previous reviews including cross references, abstracts, conferences, symposia proceedings, expert informants and journal handsearching in the English language. All trials using random allocation to peri-operative thyroid hormone therapy (supplementation or replacement) compared to control (placebo or no therapy) in infants (birth to one year of age) undergoing cardiac surgery requiring cardiopulmonary bypass. Thyroid hormone therapy must be tri-iodothyronine. Primary clinical outcomes included measures of post-operative morbidity and mortality. The standard methods of the Cochrane Neonatal Review Group were used in the assessment of trial quality. Treatment effects were expressed using relative risk (RR) and mean difference (MD). Two very small studies were identified that tested peri-operative thyroid hormone supplementation or replacement in infants aged less than one year undergoing cardiac surgery (Chowdhury 2001; Portman 2000). In the Chowdhury 2001 study, a subgroup of nine neonates was eligible for this review. No deaths occurred during either study. Chowdhury 2001 found no significant effect of peri-operative thyroid hormone supplementation in neonates on either length of hospital stay or duration of mechanical ventilation. Portman 2000 found no significant difference in dopamine requirements for the treatment versus control groups for the first 24 hours post operatively, while in the Chowdhury neonatal subgroup, inotrope requirements were significantly lower in the treatment group. Portman 2000 re