Oral Levothyroxine Prophylactic Administration on Bleeding and Hemoglobin Changes During and after Total Hip Arthroplasty in Patients with a History of Ischemic Heart Disease: A Randomized Clinical Trial

The reduction of thyroid hormones during surgery can affect the amount of bleeding. This study aimed to evaluate the effects of prophylactic administration of oral levothyroxine on bleeding and hemoglobin levels during and after THA in patients with a history of IHD. In this double-blinded clinical trial, 40 THA candidates with a history of IHD were randomly divided into intervention and control groups. Twelve hours before the induction of anesthesia, patients in the intervention group received 20 µg levothyroxine, and patients in the placebo group received the same amount (one-fifth of a tablet) of a placebo. Also, during surgery, one tablet containing either 100 mg levothyroxine or a placebo was dissolved in 30 ml of water, and 20% of it was fed to the patients by gavage. One, two, three, and 12 hours after surgery, as well as on days 1st, 2nd, and 4th post-surgery, the same amount of the drug was given to the patients. Changes in hemoglobin level, bleeding volume (during and after surgery), and the number of blood units received were compared between the two groups.  Red blood cell count (RBC) (intervention: P=0.855 and control: P=0.214), hemoglobin level (intervention: P=0.673 and control: P=0.123), and hematocrit (intervention: P=0.666 and control: P=0.096) were more stable in the intervention than in the control group. Also, bleeding volume was considerably lower in the intervention group (P=0.339) than in the control group (P=0.032). Also, serum volume in the operation room (P=0.019) and post-surgery (P=0.041) and the number of packed cell units received in the operation room (P=0.014) and after surgery (P=0.041) were significantly lower in the intervention group than in the control group. The prophylactic administration of oral levothyroxine reduced bleeding volume and the need for blood transfusion and rendered blood indices (Hb, HCT, RBC, PT, and APPT) more stable in THA candidates with a history of IHD.