Citrate anticoagulation (RCA) during
continuous renal replacement therapy (CRRT) in intensive care units (ICUs) is a practical application of a regional technique in which anticoagulation is virtually restrained to the extracorporeal circuit. This technique involves a different mental approach to anticoagulation, which gives RCA an advantage over systemic anticoagulation. The efficacy of anticoagulation depends on the level of citratemia reached in the circuit (from 2 to 6 mmol/L) and the associated decrease in ionized
calcium (from 0.5 to 0.1 mmol/L). Compared with
heparin in ICU patients in terms of efficacy and safety,
citrate is able to maintain circuit patency for the same time, if not longer. It also reduces the risk of
bleeding and the need for
blood transfusions. Metabolic alterations during RCA such as metabolic
alkalosis,
hypocalcemia and
hypernatremia are rare and of little clinical impact; their incidence is similar to those reported during CRRT with
heparin. In patients at risk of
citrate accumulation due to liver metabolism failure, the
citrate load returning to the patient can be reduced by increasing the dialysis effluent volume. The popularity of RCA worldwide is neither high nor uniform. Apart from clinical indications, its diffusion is influenced by local and logistic conditions, the level of staff skill, and economic factors. However, thanks to the availability of dedicated monitors, disposable materials, and easy-to-learn operative protocols fitting patients' needs the use of RCA is increasing. For these reasons, RCA is expected to become the ruling anticoagulation approach during CRRT in ICUs.