Perfusion temperature, thyroid hormones and inflammation during pediatric cardiac surgery.
OBJECTIVE
During cardiopulmonary bypass (CPB) surgery there are several alterations in concentrations of thyroid hormones. Although hypothermia and inflammation have been implicated in the disturbed thyroid axis during CPB, these issues are far from clear.


RESULTS
We measured serum/plasma concentrations of thyroid hormones and inflammatory mediators in children with body weight <10 kg, undergoing open heart surgery, randomized to mild (n=15, 32 degrees C) or moderate (n=15, 25 degrees C) hypothermia. During CPB there was a marked decrease in triiodothyronine (T3), free thyroxin (FT4) and thyroid-stimulating hormone (TSH), followed by a slight increase after 24 h, but without normalization 48 h after CPB. There was no difference in the thyroid response between the two hypothermia groups. During CPB the maximal changes in plasma levels of interleukin (IL)-6 and the chemokines, regulated on activation normal T cell expressed and secreted (RANTES) and monocyte chemoattractant protein (MCP)-1 were inversely correlated with the maximal changes in serum levels of T3.


CONCLUSIONS
Our findings in this randomized trial do not support a role for hypothermia as a major cause of altered thyroxin responses in children undergoing CPB. Our finding may also suggest that in addition to IL-6, other inflammatory cytokines, such as chemokines, should be further investigated for their possible influence on the thyroid axis during CPB.
Eggum
Rune
R
Department of Thoracic and Cardiovascular Surgery, Oslo University Hospital, Rikshospitalet, University of Oslo, Oslo, Norway. rune.eggum@vestreviken.no
Ueland
Thor
T
Mollnes
Tom E
TE
Videm
Vibeke
V
Fiane
Arnt E
AE
Aukrust
Pål
P
Lindberg
Harald L
HL
D015415:Biomarkers / Q000097:blood; D006348:Cardiac Surgical Procedures / Q000009:adverse effects*; D002315:Cardiopulmonary Bypass / Q000009:adverse effects*; D018932:Chemokine CCL2 / Q000097:blood; D018946:Chemokine CCL5 / Q000097:blood; D005067:Euthyroid Sick Syndromes / Q000097:blood / Q000209:etiology*; D005260:Female; D006801:Humans; D007036:Hypothermia, Induced / Q000009:adverse effects*; D007223:Infant; D018836:Inflammation Mediators / Q000097:blood*; D015850:Interleukin-6 / Q000097:blood; D008297:Male; D011446:Prospective Studies; D018746:Systemic Inflammatory Response Syndrome / Q000097:blood / Q000209:etiology*; D013963:Thyroid Hormones / Q000097:blood*; D013972:Thyrotropin / Q000097:blood; D013974:Thyroxine / Q000097:blood; D013997:Time Factors; D014284:Triiodothyronine / Q000097:blood
D015415:Biomarkers; C111835:CCL2 protein, human; C483024:CCL5 protein, human; D018932:Chemokine CCL2; D018946:Chemokine CCL5; C508600:IL6 protein, human; D018836:Inflammation Mediators; D015850:Interleukin-6; D013963:Thyroid Hormones; D014284:Triiodothyronine; D013972:Thyrotropin; D013974:Thyroxine