Topical Iodine Containing Antiseptics And Subclinical Hypothyroidism In Preter Infants:

Nema Hussein Ahmed Zeriban

SummeryPage No. 135SummeryThe excess of iodine has a well know inhibitory effect on thyroid hormone synthesisand release ( the Wolf chaikoff effect) . This effect is transient and a mature gland canescape from its inhibition after 48h . (Catherine et al., 1995) .Iodine is known to induce transient hypothyroidism in term infants undergoingmajor iodine exposure as in surgical procedures ( Digoerge , 2000) . However the adverseeffects of topical iodine is controversial .Pretenn infants are especially vulnerable to the effect of topical iodine as they have. a relatively small surface area, and a thin , more permeable skin, with less subcutaneousfat than full term infants . Unlike mature thyroid glands , those of pretenn infants may beunable to escape the Wollf - Chaikoff effect ( Nebama et al., 1997) .To assess the adverse effects of topical iodine on thyroid function of pretenn infants, we studied these effects on 49 pretenn neontates admitted to neonatal intensive care unitof Damonhour teaching hospital during a period of 10 monthes .We divided our cases into 2 groups:• The first group is the iodine group in whom povidone iodine (Betadine) was usedas a routine antiseptic for the disinfection of umbilical stumb , venipuncture ,umbilical catheter or any minor procedures ( Gr I . n = 25 ) .• The second group was the chlorohexidine group where chlorohexidine gluconate( savlon ) was used as a routine antiseptic ( G r II n = 24 ) .SummeryPage No. 136• For both groups, full history, thorough clinical examination and routine laboratoryinvestigations were done . In addition to the specific tests for thyroid function whichwere done at the first and the tenth days of admission and cases of congenitalhypothyroidism were excluded.• Our study revealed a significant decrease in the level of T4 and T3 levels with amore significant increase in ISH level and urinary iodine excretion among thecases of group I ( iodine group ) than those of group II ( Chlorhexidine group ) .This means that topical iodine has an actual inhibitory effect on premature thyroidglands especially those of younger babies who are smaller in birth weight weightand more ill .