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

Abstract

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.