Recent data on RCA in patients with liver failure undergoing CRRT have provided important information. In spite of substantial increases in citrate levels, the metabolic consequences were less significant than expected: a trend towards metabolic alkalosis was found instead of acidosis, and no significant electrolyte disturbances (including hypocalcemia) were observed [26]. Blood citrate levels were related to the calcium ratio; prothrombin activity <26% and lactate level >3.4 mmol/L proved to be acceptable predictors of citrate accumulation. However, a more recent retrospective study suggested that we may further restrict the exclusion criteria for RCA, describing the association between the incidence of citrate accumulation and more elevated lactate levels (>7.5 mmol/L) [23]. Most of these issues can be deemed valid in the case of extracorporeal liver support treatments usually adopted as a “bridge” to liver transplantation or liver recovery, such as the Molecular Adsorbent Recirculating System and Prometheus System. In our experience with Prometheus, RCA was a safe and effective anticoagulation modality [27, 29, 30].
Conclusion
The use of citrate represents a valid alternative to traditional anticoagulation with heparin during CRRT since it reduces the bleeding risk and increases the efficiency of the treatment. The increase of filter life span in fact, is not a goal to be pursued in itself, but the reduction of the filter clotting events within the first 48–72 h reduces the discrepancy between the prescribed and delivered dialysis doses. With recent technological innovations, the RCT during CRRT can be conducted safely with minimal risk of complications even in patients at the highest risk of citrate accumulation such as patients with liver dysfunction.
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