Preoperative oraltriiodothyronine improves clinical parameters and prevents non-thyroid illness for patients undergoing valvular heart surgery

ABSTRACT

Non-thyroid illness [NTI] is a temporary condition that can affect patients undergoing open heart surgeries. Preoperative oral T3 for patients undergoing valvular heart surgeries has been studied in few trials with no beneficial clinical outcome. The aim of this study was to,test different doses of oral T3at different duration of administration on the clinical parameters and the prevention of NTI for patients undergoing valvular heart surgeries. A total of 45 patients undergoing valvular heart surgeries were randomly allocated into three groups group I [n=15] received 50microg /day of oral T[3] for three successive doses before induction of anesthesia; group II [n=15] received 50microg of oral T[3] as a single dose three hours before induction of anesthesia; and group III [N=15] did not receive T[3] tablets. Systolic, diastolic and mean blood pressure and heart rate were recorded before the start of treatment 48 hours [TO] and 24 hours [Tl] prior to surgery, Pre induction of anesthesia [T2], post induction of anesthesia [T3] and at weaning from CPB [T4]. Systolic pulmonary artery pressure was measured at TO by TTE, T3 and T4 by TEE. Number of patients who needed inotropic support and pacemaker and doses of inotropic support needed were recorded at T4. TSH, freeT4 and freeT[3] were measured at TO, T2 and 24 hour after admission to the ICU [T5]. Blood pressure was significantly higher in group I [P<0.05] at T3 and T4.SPAP was significantly lower in group I compared with other groups at T4 [37.614.5 vs 41.313.9 vs 43.313.5 mm Hg respectively, P value<0.05]. The doses of adrenaline at T4 was lower in group I compared with groups II and III [.0110.02 vs0.0410.01 vs. 0.0710.01 ug/kg/min, respectively, P value <0.01]. At T2 free T[3] was significantly higher in group I compared with groups II and III [3.310.49 vs2.8 +/- 0.49vs2.3i0.37 pg/ml, respectively, P value<0.01]. At T5 free T[3] was significantly higher in group I compared to groups II and III [3.110.53 vs 2.3610.31 vs 1.931.027 pg/ml, respectively.P value <0.01] and TSH was significantly lower in group I compared to groups II and III [3.7210.35 vs 4.9410.63 vs 6.8110.48 ulU/ml, respectively. P value <0.01]. Three successive doses of 50 ng /day of oral triiodothyronine given 48 hours before induction of anesthesia, maintained blood pressure with lower inotropic support and lower systolic pulmonary artery pressure and prevented NTI in patients undergoing valvular heart surgeries