ECMO-/ECLS

of venous catheter devices, mechanical ventilation, malignancy, prolonged stay
in the hospital (> 5 days). Additionally, increased awareness of VTE as a
condition in children and improved diagnostic imaging most likely contributed to
the increasing prevalence of VTE that has been seen [27].
The neonate has an increased risk of venous thromboembolism due to its
inherent prothrombotic hemostasis system. Levels of Protein C, Protein S,
antithrombin are low compared to normal adult ranges. Despite the lower level of
Vitamin K dependent clotting factors this does not translate to a lower risk of
VTE. Fibrinolysis also is less active during the neonatal period [28]. In addition
to an immature hemostasis system, newborn infants can have inherited and
acquired thrombophilic traits similar to adults. The most common association
with VTE in neonates, however, is an indwelling central venous catheter. One
study suggests up to 80% of VTE in neonates and infants were related to central
venous catheters [29]. While the incidence and prevalence of VTE has
increased in the neonate, there still is a paucity of randomized controlled trials
with which to derive an evidence based therapeutic approach.
Management of thrombus utilizing unfractionated heparin remains the
most common therapy. Heparin binds to antithrombin III, causing a
conformational change in ATIII, making it a much better inhibitor of factor II and
X. Initial loading dose of 75 units/kg followed by a continuous infusion of 28
units/kg is a safe starting point. It should be adjusted to a aPTT level that is two
to three times the baseline level or a heparin level that is 0.2-0.4 u/ml. [30]. If