title: Identifying infants at risk of marked thyroid suppression post-cardiopulmonary bypass.
abstract: OBJECTIVE
  The clinical benefit of tri-iodothyrinone (T(3)) replacement following congenital heart surgery with cardiopulmonary bypass (CPB) is not clear in unselected cohorts of children. Infants with more marked thyroid hormone suppression or prolonged post-CPB recovery may benefit from T(3) replacement. This study aimed to identify infants at risk of more marked suppression by examining the relationship between organ support parameters during CPB and post-operative thyroid hormone levels.
  
  
  METHODS
  Prospective observational study in a tertiary referral centre for congenital heart surgery.
  
  
  METHODS
  36 infants less than 12 months of age were recruited following CPB.
  
  
  RESULTS
  Thyroid hormone levels were measured on admission to the intensive care unit and on post-operative days 1 and 2. Increasing CPB time was associated with decreasing admission free T(3) and thyroid-stimulating hormone. Younger, smaller infants had lower admission levels of free T(3) on univariant analysis. Infants who continued to require ventilation 48 h after admission to the ICU had a mean free T(3) level on post-operative day 2 that was 0.9 pmol/l lower than in those who had been extubated.
  
  
  CONCLUSIONS
  Prospective studies of T(3) replacement in selected young infants (less than 3 months) with long CPB time (greater than 120 min) during congenital heart surgery are warranted.
authors.affiliation: Pediatric Intensive Care Unit, Queensland Center for Congenital Heart Disease, Prince Charles Hospital, Rode Road, Chermside, Brisbane, QLD 4032, Australia. Nikolaus_Haas@ health.qld.gov.au
authors.forename: Kevin
authors.initials: K
authors.lastname: Plumpton
authors.forename: Nikolaus A
authors.initials: NA
authors.lastname: Haas
mesh_terms: D002315:Cardiopulmonary Bypass / Q000009:adverse effects*; D005260:Female; D006330:Heart Defects, Congenital / Q000601:surgery; D006801:Humans; D007223:Infant; D015278:Intensive Care Units, Pediatric; D008297:Male; D011446:Prospective Studies; D011793:Queensland; D018570:Risk Assessment; D014284:Triiodothyronine / Q000008:administration & dosage*
chemical_list: D014284:Triiodothyronine