[Thyroid function of burned patients: effect of iodine therapy]

Thyroid function was studied in 3 groups of adults (group I = 13 burned patients treated with non iodinated antiseptic, group II = 15 burned patients treated with polyvidone iodine, group III = 50 control subjects) in order to examine: the thyroid hormone status in burned patients, the possible incidence of plasma iodine overload on these endocrine parameters. Burned skin area and thyroid function were measured before treatment, then weekly for 3 weeks. Before treatment a decrease in plasma T4 and T3 with an increase in reverse T3 (rT3) and a decrease in plasma thyroxin binding globulin (TBG) were observed in burned patients. Free T4 index (T4/TBG) was normal, but T3 resin uptake (T3RU) was elevated. During treatment, plasma iodine increase sharply from 6.4 +/- 0.4 to 20.7 +/- 4.7 micrograms/100 ml (p less than 0.02) in group II. Endocrine parameters (not different between group I and II) progressively returned to normal, except for T3RU which remained elevated until the third week. rT3, T4 and T3RU correlated (p less than 0.001) with burned skin area. To conclude, the reversible particularities of thyroid function in burned patients are positively correlated with burned area. The thyroid function does not seen to be modified by plasma iodine overload.