[Anticoagulation of extracorporeal circuit in critically ill patients]

Heparin is currently the most popular anticoagulant for extracorporeal circuits in ICUs. Yet, heparin may also be considered as an invasive procedure possibly complicated by bleeding in post-surgical patients who are often septic and with largely exposed skin areas. Over time many alternatives in anticoagulation have been suggested and applied with varying outcomes, including both systemic (heparinoids, thrombin inhibitors, nafamostat, prostacyclin) and regional (saline flushes, protamin coupled heparin, cit-rate). Among all, citrate is emerging as the most promising method with regard to efficacy, safety and feasibility, beside its being more and more used, particularly in North America and northern European countries. Many reasons could explain this success, such as low costs, uncomplicated technology, easy handling and complete reversibility of its anticoagulant activity. Above all, the main advantage of citrate is its capacity to provide anticoagulation specific to the extracorporeal circuit with-out involving the patient. In critically ill patients the bleeding rate is more frequent in continuous than in intermittent treatments, and the bleeding risk is often per se the main factor hindering the practical feasibility of ''continuous'' treatment.