Читать книгу Current Perspectives in Kidney Diseases - Группа авторов - Страница 35

The use of RCA in patients with liver dysfunction is often considered hazardous due to deranged liver metabolism and increased risk of citrate accumulation. However, many of the potential risks related to the use of citrate in these patients have been overcome, thanks to the recent evolution in dialysis machine engineering technology [24]. The new software is in fact able to adapt citrate infusion to blood flow changes, thus limiting the risk of an inappropriate citrate/blood flow ratio. Moreover, with CRRT monitors the citrate dose can be modified at any time during the treatment in the event of a documented or suspected citrate overload. Last, modulation of the convective and/or diffusive CRRT dose may prevent the development of citrate accumulation, due to the substantial removal of citrate with the effluent fluid [7].

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].