Continuous renal replacement therapy (CRRT) in patients with liver disease: is circuit life different?

Background/aims: Clotting of haemofiltration circuits is a major complication of continuous renal replacement therapies (CRRT), yet systemic anticoagulation risks haemorrhage. Traditionally, patients with liver failure are managed with no or minimal anticoagulation, because of abnormal clotting tests and the perceived, increased bleeding risk.
Methods: We retrospectively reviewed CRRT circuit life in 50 patients; 3 groups of liver failure patients treated with CRRT (acute liver failure (ALF), acute on chronic liver disease (ACLD) and post-elective liver transplantation (LTx)), with two control groups; systemic sepsis (SS) and haematological malignancy (Haem).
Results: CCRT circuit life was significantly greater in the Haem group, compared to the others; 24.3+/-23.9h, vs. 11+/-10.5 ALF, 11.6+/-6.6 ACLF, 7.4+/-5.1 LTx and 9.2+/-6.5 SS, p<0.05, with Haem group requiring fewest new CCRT circuits within 48h; 2.4+/-1.0 vs. 4.3+/-1.3 ALF, 4.2+/-2.1 ACLF, 5.3+/-1.5 LTx and 4.6+/-1.5 SS, p<0.05 and least blood transfusions; 1.2+/-1.3 vs. 4.8+/-4.2 ALF, 4.2+/-4.1 ACLF, 2.2+/-2.1 LTx and 3.0+/-1.5 SS. Transmembrane pressures were higher in those CCRT circuits with haemofilter/dialyzer clotting, compared to other causes, such as access dysfunction (123+/-74 vs. 71.8+/-29.3 mm Hg, p=0.009). In those patients in whom anticoagulation was started due to repeated filter clotting, circuit life improved from 5.6+/-3.4 to 19+/-12.7h, p<0.01.
Conclusion: Despite abnormal laboratory coagulation tests and thrombocytopenia, CCRT circuits clot frequently in liver failure patients. Anticoagulation did improve CRRT circuit survival without an obvious increase in bleeding or blood transfusion requirement. Thus anticoagulation should be considered in these patients with repeated circuit clotting.