Thyroid Function, Metabolism, and Severity Scorings in Brain Dead Patients

Abstract

Background and Objectives: Brain death may lead to hormonal depletion, metabolic derangement and multiple organ dysfunction. We have carried out present study to examine the effects of brain death on the thyroid function, metabolic indices, and the severity scoring systems. Methods: 13 adults patients admitted for organ donation or brain death evaluation were examined after brain death was confirmed. Thyroid hormones measured were thyroid stimulating hormone (TSH), triiodothyronine (T3), thyroxine (T4), and free thyroxine (FT4). The metabolic indices measured were arterial ketone body ratio (AKBR), lactic acid (LA), and base deficit (BD). as for reference to the severity scoring systems, APACHE III and multiple organ failure score (MOFS) were assessed on the day of brain death confirmation. Arterial blood was drawn for all measurements. Results: As for the thyroid function, there were significant decreases in T3 (40.48±20.96 ng/dL) and T4 (3.47±2.15 ug/dL), but no significant change in FT4 (0.75 0.31 ng/dL) and TSH (1.12±1.37 pIU/mL) compared to the normal range. Significant decreases in AKBR (0.39±0.31) and BD (-9.46±5.83 mmol/L), and significant increase in LA (2.57±2.46 mmol/L) In metabolic indices, were shown. as for severity scoring systems, APACHE III score (101.54±19.41) and MOF score (9.11±2.57) indicated a high mortality. There were significant correlation between thyroid hormones (r=0.565-0.781) but no correlation among other indices. Also, significant inverse correlations were shown between base deficit and lactic acid (r=-0.660), APACHE III score (r=-0.726) and MOF score (r=-0.604). The highest correlation was observed between APACHE III score and MOF score (r=0.851). Conclusions: As for the thyroid function, significant decrease in T3 and T4, and almost normal range of FT4 and TSH imply the euthyroid sick syndrome. Abnormal finding of the metabolic parameters indicates an inhibition of the aerobic metabolic rate of the body as a whole. And the severity scoring parameters are compatible with high mortality.