Antithrombotic Therapy in Children: Short-term Treatment
Short-term Treatment: Numerous forms of therapy have been used in individual patients, including fresh frozen plasma (FFP), PC concentrate, cryoprecipitate, prothrombin complex concentrate, heparin, LMWH, aspirin, sulfinpyrazone, corticosteroids, vitamin K, aprotinin, and AT concentrate. One approach is to initiate treatment with 10 to 20 mL/kg of FFP ql2h. Plasma PC levels achieved with these doses of FFP varied from 15 to 32% at 30 min after infusion, and from 4 to 10% at 12 h. Doses of PC concentrate administered in the literature have ranged from 20 to 60 U/kg. A dose of 60 U/kg resulted in peak PC levels >0.60 U/mL. Replacement of PC should be continued until the clinical lesions resolve, which is usually in 6 to 8 weeks.
The one newborn with homozygous PS deficiency was treated with both FFP and ciyoprecipitate, which contain similar amounts of PS. A pharmacokinetic study was performed following the infusion of 10 mL/kg of FFP and reported a recovery of PS at 2 h of 0.23 U/mL and at 24 h of 0.14 U/mL read natural asthma treatment. The PS was entirely in the C4b-bound fraction on crossed immunoelectrophoresis. The approximate half-life of PS in this infant was 36 h.
Long-term Treatment: The modalities used for longterm management of infants with homozygous PC deficiency include oral anticoagulant therapy, intermittent PC replacement with PC concentrate, and liver transplantation. PC replacement may not prevent further thrombosis in the presence of a risk factor such as a CVL. Currently, the majority of children are treated with oral anticoagulants. When therapy with oral anticoagulants is initiated, the infant, to avoid skin necrosis, should continue receiving PC or PS replacement until the INR is between approximately 3.0 and 4.5. To some extent, these patients need to be titrated for the lowest dose that prevents skin necrosis. Patients with homozygous PC or PS deficiency but with detectable plasma concentrations have also been treated with LMWH. The latter approach avoids the risk of oral-anticoagulant-induced skin necrosis and likely decreases the risk of bleeding associated with high doses of oral anticoagulants.