A study to evaluate serum free triiodothyronine levels as a predictive indicator of outcome in critically ill children


  • Muruli B. H. Department of Paediatrics, KIMS, Bangalore, Karnataka, India
  • Bhavya G. Department of Paediatrics, KIMS, Bangalore, Karnataka, India
  • Chaitra K. M. Department of Paediatrics, KIMS, Bangalore, Karnataka, India




Critically ill children, Euthyroid sick syndrome, Free triiodothyronine


Background: Critical illness is a life-threatening multisystem process requiring support of failing vital organ systems without which survival would not be possible. Euthyroid sick syndrome is one of the commonly seen endocrine changes in critically ill patients and is considered to be associated with adverse outcome in ICU patients. Objective of this study was to assess free triiodothyronine (FT3) in critically ill children and to associate it to the disease severity and clinical outcome in comparison to PRISM score.

Methods: This was an observational study conducted on 120 critically ill children aged between 1month and 18 years admitted in PICU of a tertiary care hospital. All children who met inclusion and exclusion criteria were subjected to initial evaluation, PRISM III scoring and also FT3 levels was estimated twice in the critically ill patients.

Results: In present study, out of 120 subjects studied, 34 succumbed and 86 survived. Low FT3 was seen in 90 (75.00%) children. The mean level of FT3 was significantly lower at admission and discharge in non-survivors than in survivors (P<0.01) and also Compared with survivors, non-survivors had higher PRISM III scores (26.65±9.64vs 15.21±7.38, P<0.001). In survivors there was a significant improvement in the mean levels FT3 from admission to discharge (P<0.01) Where as in non-survivors there was a further decrease in the mean levels of FT3 however it was not statistically significant (P>0.05). Serum FT3 at discharge is a good predictor of mortality with AUC of 0.9175±0.0620.

Conclusions: FT3 is good independent predictor of ICU mortality.


Walter C. Wisdom of the Body. United States: W.W. Norton and Company; 1932.

Economidou F, Douka E, Tzanela M, Nanas S, Kotanidou A. Thyroid function during critical illness. Hormones. 2011;10(2):117-24.

Wang F, Pan W. Relationship between thyroid function and ICU mortality: a prospective observation study. Critical care. 2012:16:R11.

Naby EA, Selim S, Mohsen M, Helmy M. Thyroid function in mechanically ventilated patients with acute respiratory failure: Prognostic value and its relation to high-sensitivity C-reactive protein. Egyptian J Chest Dis Tuberculosis. 2015;64(1):175-81.

Anand NK, Chandra V, Sinha RSK, Chellani H. Evaluation of thyroid functions in critically ill infants. Indian Pediatr. 1993;31:1233-7.

Uzel N, Neyzi O. Thyroid function in critically ill infants with infections. Pediatr Infect Dis. 1986;5:516-9.

DeGroot LJ. Non-thyroidal illness syndrome is functional central hypothyroidism, and if severe, hormone replacement is appropriate in light of present knowledge. J Endocrinol Invest. 2003;26:1163-1170.

Suvarna J, Fande C. Serum thyroid hormone profile in critically III children. Indian J Pediatr. 2009;76(12):1217-21.

Economidou F, Douka E, Tzanela M, Nanas S, Kotanidou A. Thyroid function during critical illness. Hormones (Athens). 2011;10(2):117-24.

Coceani M, Iervasi G, Pingitore A, Carpeggiani C, L’Abbate A. Thyroid hormone and coronary artery disease: from clinical correlations to prognostic implications. Clin Cardiol. 2009;32:380-5.

Wang F, Pan W, Pan S, Wang S, Ge Q, Ge J. Usefulness of N-terminal probrain natriuretic peptide and C-reactive protein to predict ICU mortality in unselected medical ICU patients: a prospective, observational study. Crit Care. 2011;15:R42.

Bayarri VM, Sancho S, Campos C, Faus R, Simon JM, Porcar E et al. The euthyroid sick syndrome in severe acute illness. Presse Med. 2007;36:1550-6.






Original Research Articles