en Internal Internal Original Article Original Article <font face="Times New Roman" size="3"> </font><p style="margin: 0cm 0cm 0pt 176.05pt"><b><i><span style="color: blue"><font face="Times New Roman" size="3">Abstract</font></span></i></b></p><font face="Times New Roman" size="3"> </font><p style="margin: 0cm 0cm 0pt 161.6pt text-indent: 0cm"><font face="Times New Roman"><b><i><span style="color: blue font-size: 10pt">Background: </span></i></b><span style="font-size: 10pt">The thyroid hormones influence on all metabolic pathways. After heart surgery using cardiopulmonary bypass (CPB), serum T3 decreases and remains low for at least 24 hours. Several studies on pediatric have reported reduction of thyroid hormones after heart surgery. This study aimed to investigate the status of thyroid function tests in children with CPB surgery.</span></font></p><font face="Times New Roman" size="3"> </font><p style="margin: 0cm 0cm 0pt 161.6pt text-indent: 0cm"><font face="Times New Roman"><b><i><span style="color: blue font-size: 10pt">Methods:</span></i></b><span style="font-size: 10pt"> This study was carried out based on the available data on 132 children aged less than 15 years suffering from CHD. The patients underwent open heart surgery in Rajaie Center in Iran from January to November 2010. The thyroid hormone levels were measured shortly after admission, and postoperatively in Intensive Care Unit (ICU) and thereafter at 12, 24 and 48-hour intervals. The patients’ gender, age, weight, body mass index, heart disease details, previous cardiac surgeries, and cardiac surgery-related data such as pump time, aortic clamping time, hypothermia duration, postoperative hemodynamic status and postoperative use of inotropic drugs were recorded and analyzed</span></font></p><font face="Times New Roman" size="3"> </font><p style="margin: 0cm 0cm 0pt 161.6pt text-indent: 0cm"><font face="Times New Roman"><b><i><span style="color: blue font-size: 10pt">Results:</span></i></b><span style="font-size: 10pt"> <span style="color: black"><font size="2">All patients showed a decrease in T3, T4 and TSH and an increase in T3-resin uptake after surgery. Eventually, 3 (3.2%) patients died. Preoperatively, there was a significant association between the reduction in the thyroid hormone levels and inotropic drugs as well as the type of the heart disease (p<0.05)</font></span>.</span></font></p><font face="Times New Roman" size="3"> </font><p style="margin: 0cm 0cm 0pt 161.6pt text-indent: 0cm"><font face="Times New Roman"><b><i><span style="color: blue font-size: 10pt">Conclusion: </span></i></b><span style="font-size: 10pt">There is an association between post-operative inotropic drugs administration and reduction thyroid hormones levels in patients undergoing congenital heart disease cardiopulmonary bypass surgery. </span></font></p><font face="Times New Roman" size="3"> </font> Non-thyroidal Illness Syndrome, Cardiopulmonary bypass, Cyanosis, Inotropic drugs 235 242 http://caspjim.com/browse.php?a_code=A-10-62-207&slc_lang=en&sid=1 Kazem Babazadeh 10031947532846002519 10031947532846002519 No Avisa Tabib avtabib@yahoo.com 10031947532846002520 10031947532846002520 Yes Peyman Eshraghi 10031947532846002521 10031947532846002521 No Hooman Bakhshandeh 10031947532846002522 10031947532846002522 No Hassan Zamani 10031947532846002523 10031947532846002523 No