The Effect of Oral Levothyroxine on Bleeding and Need for Inotropic Agents in Patients Undergoing Coronary Artery Bypass Graft

Following coronary artery bypass graft (CABG), T3 level reduces and this situation can affect the function of cardiovascular system. This study aimed to evaluate the effect of oral levothyroxine on need for inotropic agents and bleeding in patients undergoing cardiopulmonary bypass.
In this randomized clinical trial study, 70 patients undergoing CABG randomly divided into two groups. The case group received oral levothyroxine (20 mg: the first dose at the night before surgery and the followings two hours after intensive care unit (ICU) admission and then every 12 hours for 24 hours, a total of 4 doses) and the control group received placebo with the same dose. Hemoglobin levels, requirement to inotropic agents, occurrence of bleeding, and volume of hemorrhage and blood products consumption were determined and compared between the two groups.
Findings: No significant differences were detected between the groups in the need for inotropic agents, blood hemoglobin, bleeding, and blood products consumption. But, blood loss volume in the intensive care unit was significantly less in the case group compared to the placebo group (P = 0.005).
Our study showed that administration of oral levothyroxine is associated with lower volume of blood loss in intensive care unit; but caused no significant decrease in the need for inotropic support.