Surface-heparinized neonatal ECMO circuit--an experimental animal study.

The present experiment examined the capacity of the Carmeda Bioactive Surface to prevent clot formation in an ECMO circuit designed for neonatal use. The Terumo Capiox oxygenator was used in the seven experiments. Mongrel dogs were perfused with veno-arterial bypass at a low flow rate of 200 ml/min. Without any blood heparinization, the circuit was totally occluded within a few hours. With a very low heparin infusion (10 IUxkg -1xh -1) extracorporeal blood flow could be maintained despite some clots forming in the oxygenator. With a small bolus injection of heparin (20 IU/kg) and a low continuous heparin infusion (20 IUxkg -1xh -1) the ECMO circuit showed negligible clotting. With better haemodynamic design of the device in combination with a thrombo-resistant surface, it may be possible to decrease the need for blood heparinization in the neonatal ECMO circuit.