Cardiopulmonary bypass: ‘a low T4 and T3 syndrome’ with blunted thyrotropin (TSH) response to thyrotropin-releasing hormone (TRH)

Giuseppe Robuschi, Dante Medici, Francesco Fesani, Guglielmo Barboso, Mara Montermini, Lorenzo D’Amato, Eliana Gardini, Elisabetta Borciani, Elisabetta Dallaglio, Mario Salvi, Angelo Gnudi, Elio Roti

Research output: Contribution to journalArticlepeer-review


Thyroid hormone serum concentrations, the thyrotropin (TSH) and prolactin (PRL) response to thyrotropin-releasing hormone (TRH) were evaluated in patients undergoing cardiopulmonary bypass (CPB) conducted in hypothermia. During CPB a marked decrease of thyroxine (T4) and triiodothyronine (T3) concentration with a concomitant increase of reverse T3 (rT3) were observed similarly to other clinical states associated with the ‘low T3 syndrome’. Furthermore, in the present study elevated FT4 and FT3 concentrations were observed. In a group of patients, TRH administered during CPB at 26 °C elicited a markedly blunted TSH response. In these patients, PRL concentration was elevated but did not significantly increase after TRH. The increased concentrations of FT4 and FT3 were probably due to the large doses of heparin administered to these patients. Thus, the blunted response of TSH to TRH might be the consequence of the elevation of FT4 and FT3 in serum, however, other factors might play a role since also the PRL response to TRH was blocked.

Original languageEnglish
Pages (from-to)151-158
Number of pages8
JournalHormone Research in Paediatrics
Issue number3
Publication statusPublished - 1986


  • Cardiosurgery
  • FT<inf>3</inf>
  • Ft<inf>4</inf>
  • PRL response to TRH
  • RT<inf>3</inf>
  • T<inf>3</inf>
  • T<inf>4</inf>
  • Tsh

ASJC Scopus subject areas

  • Endocrinology
  • Endocrinology, Diabetes and Metabolism
  • Pediatrics, Perinatology, and Child Health


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