Background: The function of thyroid hormone is to stimulate the regulation of ?-adrenergic receptors, whose function is to increase the inotropic effect of the heart myocardium. Euthyroid sick syndrome is a disorder of non-metabolic thyroid function, which is characterized by a decrease in Triiodothyronine (T3) levels in patients with non-thyroid systemic disease, such as sepsis. Low level of serum T3 hormone can be a potentially high risk factor of death in sepsis. The purpose of this study is to see the relationship of decreased serum T3 levels, as factor that affects the death of sepsis patients.
Methods: This study use a Nested case-control design. The subjects are all children aged 1 month-18 years who were diagnosed with sepsis in the Intensive Care Unit Room of Sanglah Hospital Denpasar from September 2017 to January 2019.
Result: A total of 90 children are included, 44 subjects died and 46 subjects survived. Median age in dead subject is 10,5 months (IQR=44). Nutritional Status is well nourish. Median of procalcitonin levels is 63 (IQR=88,9).  Median of T3 serum levels is 0,72 (IQR=0,38). Median of PELOD-2 score is 5 (IQR=4). Bivariate analysis shows in the dead sepsis group, 95,5% have ?1 ng/dL  of total T3 level, 59,1% have ?5 of PELOD-2 score, and 63,6%  had >36 ng/mL  of procalcitonin level. Multivariate analysis found T3 serum ?1 ng/dL with OR 55,1 (95% CI 9-334,8, p<0,001) and PELOD-2 score ?5 with OR 6,5 (95% CI 1,6-26,7, p=0,01) can affect death in sepsis,  
Conclusion: this study proves that low T3 serum level is a risk factor for death in sepsis