Citrate versus unfractionated heparin for anticoagulation in continuous renal replacement therapy

Background Unfractionated heparin is the most commonly used anticoagulant in continuous renal replacement therapy (CRRT), but it can increase the risk of bleeding. Citrate is a promising substitute. Our study was to assess the efficacy and safety of citrate versus unfractionated heparin in CRRT. Methods We searched the MEDLINE, the EMBASE, the Cochrane Central Register of Controlled Trials, and the China National Knowledge Infrastructure Database until up to November 2011 for randomized controlled trials comparing citrate with unfractionated heparin in adult patients with acute kidney injury prescribed CRRT. The primary outcome was mortality and the secondary outcomes included circuit survival, control of uremia, risk of bleeding, transfusion rates, acid-base statuses, and disturbance of sodium and calcium homeostasis. Results Four trials met the inclusion criteria. Meta-analysis found no significant difference between two anticoagulants on mortality. Less bleeding and more hypocalcemic episodes were with citrate. Citrate was superior or comparable to unfractionated heparin in circuit life. Conclusions Citrate anticoagulation in CRRT seems to be superior in reducing bleeding risk and with a longer or similar circuit life, although there is more metabolic derangement. Mortality superiority has not been approved.