Background and aims Incidence of HIT in childhood is lower than in adults because of lower platelet factor 4 levels and immature immune system. After frist time cardiac surgery platelet-antibody formation has been reported to be 1,7% in neonates and 6% in children on the 5th postoperative day. With reexposure to unfractionated heparin (UFH) even 52% of children are antibody positive but only 1.3% develope symptoms.1
Methods and results Two children (3 and 3.5 years old) developed thrombopenia after Fontan procedure (after 5 and 7 days respectively). One patient suffered from cyanosis due to a thrombus in the Fontan tunnel. Both were initially treated with with continuous argatroban infusion and then switched to a vitamin k antagonist. In the second patient aPTT and INR exceeded therapeutic values during transition, because argatroban dosage was not reduced adequately. (Table 1)
Conclusion In both patients platelet count recoverd. No adverse events, especially no argatroban induced bleeding occured. aPTT and INR should be monitored closely and dosage should be adapted accordingly.
Mullen et al . Anesth Analg. 2008; 107(2):371–378
Niyati et al . Pediatric Pharmacol Ther. 2012; 17(1):12–30