Objective To study the plasma and urine concentration of tranexamic acid (TA) during cardiopulmonary bypass in infants with Tetralogy of Fallot.
Methods 5 patients with Tetralogy of Fallot received an initial dose 100 mg/kg of TA given over 10 min followed by an infusion of 100 mg/kg before the initiation of cardiopulmonary bypass (CPB). TA was measured in urine using with 1H NMR S.
Results Plasma TA concentrations (ug/mL; Mean ± SD) were 224.61 ± 195.28 at 20 min after bolus, 509.58 ± 181.571 after 60 min on CPB, 243.95 ± 32.30 at the end of operation. Urine TA concentrations (mg/mL; M ± SD) before CPB, during CPB, thoracic closing and 4 hours after operation, 4.28 ± 1.12, 3.7 ± 2.86mg/ml, 4.45 ± 2.65mg/ml, 1.20 ± 0.61mg/ml respectively. Total urine TA dose (mg; M ± SD) before CPB, during CPB, and thoracic closing, 157.5 ± 24.8, 207.20 ± 116.20mg, 485.40 ± 326.52mg respectively. The TA excrete (M ± SD) is 56.218 ± 27.61% until operation finished about 3 hours.
Conclusions A 100mg/kg initial dose of TA followed by an infusion of 100mg/kg before the initiation of CPB is sufficient enough to provide an effective plasma concentration125ug/ml for the bleeding patients with high risk. The dose of TA could be decreased.