Thyroid function during and after cardiopulmonary bypass in children.

BACKGROUND

The aim of the study was to elucidate the changes in thyroid function during and after cardiopulmonary bypass (CPB) in children.

METHODS

Triiodothronine (T3), thyroxine (T4), free thyroxine (FT4) and thyroid-stimulating hormone (TSH) were determined preoperatively, at specific times throughout CPB, and serially up to 48 h postoperatively, in 10 children (median age 35, range 23-68 months) undergoing elective surgery for congenital heart disease.

RESULTS

T3 decreased from 2.01 +/- 0.08 preoperatively to 0.94 +/- 0.10 nmol/l 24 h postoperatively (P < 0.05). T4 levels followed a pattern similar to changes in T3. FT4 increased from 17.4 +/- 0.7 preoperatively to 30.0 +/- 0.4 pmol/l after 30 min of CPB (P < 0.05). TSH decreased from 2.44 +/- 0.43 preoperatively to 0.93 +/- 0.21 24 h postoperatively (P < 0.05).

CONCLUSION

T3, T4 and TSH are significantly depressed after open heart surgery in children.