needed, heparin reversal can be reversed with protamine (1 mg protamine for
100 units of heparin).
Low molecular weight heparin (LMWH) may also be utilized and has
recently garnered more interest by neonatologists. LMWH binds to and activates
ATIII. ATIII inhibits Xa. Factor Xa is needed to convert protamine to thrombin.
LMWH is too small to directly inhibit thrombin formation. Initial dosing should be
1.5mg/kg every twelve hours. Factor Xa levels should be measured every 4
hours to obtain a level of 0.5 to 1.0 units per ml. [30] If needed, LMWH can be
reversed with protamine (1 mg protamine for 1 mg LMWH). Vitamin K levels are
not commonly used in the neonatal period.
Heparin Induced Thrombocytopenia is a procoagulant state that occurs
when heparin binds to PF4 on the platelet surface, activating platelets. Activated
platelets are cleared by the RES, causing decreased platelet counts at 5- 14
days. Diagnosis can be made by platelet aggregation test and serotonin release
(more specific, less sensitive) or an ELISA for PF4 antibodies (more sensitive,
less specific). To treat this entity, Heparin should be discontinued, and
anticoagulation with other agents such as lepuridin and argatrobam should be
done.
References
- Lacroix J, Hebert PC, Hutchinson JS, et al. Transfusion strategiein pediatric intensive care units. N Engl J Med 2007;365:1609-19. s for patients
- Valieva OA, Strandjord TP, Mayock DE, et al. Effects of transfusions in
extremely low birth weight infants: a retrospective study. J Pediatr;155:331-7.