Introduction and objective:
Continuous monitoring of coagulation is essential during venovenous Extracorporeal Membrane Oxygenation (VV ECMO) therapy because the extracorporeal circuit can activate the coagulation system and may lead to clot formation or bleeding. Various anticoagulant agents are used for this purpose, and unfractionated heparin is considered the gold standard of anticoagulant therapy. The biocompatibility of the extracorporeal circuit also allows antithrombotic treatment with low molecular weight heparins (LMWHs) administered subcutaneously (s.c.). There is increasing evidence that the use of LMWHs produces identical therapeutic effects with fewer side-effects. Our primary aim was to compare thrombotic complications and bleeding events.

Material and methods:
The study evaluated the safety and efficacy of anticoagulation with single-dose nadroparin administered s.c., compared with a twice daily regime of this LMWH during ECMO therapy in patients with severe respiratory failure treated in an intensive care unit (ICU). Changes in flow resistance in the oxygenator and the number of transfused blood products were monitored. No differences were found in bleeding events between once and twice-daily dosing of nadroparin during ECMO therapy (34% vs. 53%, p = 12).

Results:
Both regimes of administration were similar in the number of life-threatening bleeding events (p =.26) and a daily number of transfused red blood cells (p =.37). The change in flow resistance in the oxygenator was comparable between the two groups (11.28% vs. 6.13%, respectively, p = .26).

Conclusions:
Once daily administration of nadroparin appeared comparable to the twice daily regime in terms of the number of thrombotic complications.