Thyroid function and outcome in children who survived meningococcal septic shock

Objective: To investigate the time course of thyroid function, factors that affect it, and its relationship to outcome in children surviving meningococcal septic shock. Design and setting: Observational cohort study in a university-affiliated pediatric intensive care unit (PICU). Patients and participants: We divided the 44 children admitted to the PICU who survived meningococcal septic shock into those with short-stay (< 7 days, n=33) or long-stay (>= 7 days, n=11). Measurements and results: Serum thyroid hormone concentrations were determined on PICU admission and after 24 and 48 h. The Pediatric Risk of Mortality score and selected laboratory parameters were used to assess disease severity. On admission all children showed signs of euthyroid sick syndrome: low total triiodothyronine (TT3) and high reverse triiodothyronine (rT(3)) without compensatory elevated thyrotropin (TSH). Admission rT(3) levels and the TT3/rT(3) ratio were correlated with C-reactive protein levels and with time from first petechia to admission. Short-stay children only had higher TT3 and lower interleukin 6 levels at admission than long-stay children; after 48 h they showed higher total thyroxin, free thyroxin, TT3, and TSH and lower rT(3) than long-stay children. All changes in thyroid parameters within the first 24 h were related to length of PICU stay. In children receiving dopamine TSH levels and TT3/rT(3) ratios remained unchanged, whereas both values increased in those who did not receive dopamine or in whom dopamine was discontinued. Conclusions: All children surviving meningococcal septic shock showed signs of euthyroid sick syndrome on admission. Thyroid hormone level changes in the first 24 h were prognostic for length of PICU stay.