Regional citrate versus heparin anticoagulation during venovenous hemofiltration in patients at low risk for bleeding: similar hemofilter survival but significantly less bleeding

BACKGROUND: Regional citrate anticoagulation (RCA) may be a valuable alternative to systemic heparin anticoagulation during continuous venovenous hemodialysis (CVVH). RCA does not increase the risk of bleeding, but carries the risk of metabolic derangements. Clotting-free circuit survival may be increased with RCA. METHODS: Critically ill patients at low risk for bleeding were randomized for CVVH with RCA or systemic heparin anticoagulation. A maximum of 4 consecutive CVVH circuits were analyzed for every patient. Clotting-free circuit survival, adverse metabolic events and bleeding complications were recorded. RESULTS: Forty-eight patients were included in the study and randomized for RCA (n=21) or systemic heparin (n=27). A total of 142 CVVH circuits were analyzed with a median of 3 circuits per patient. Uncensored circuit survival and median clotting-free circuit survival were similar for both groups. No significant adverse metabolic events occurred in the RCA group. Major bleedings were not recorded in the RCA group, compared with 10 events in the heparin group (p<0.01). The number of red blood cell units given per day of CVVH was significantly higher in the heparin group (0.88 vs 0.43 units/day, p=0.01). Also, the mean decrease in hemoglobin concentration per day in the nontransfused stable patients, was significantly higher in the heparin group. CONCLUSION: RCA during CVVH can be performed safely, with a circuit survival similar to systemic heparin anticoagulation, but significantly lower incidence of bleeding. Citrate anticoagulation should be advocated as first choice, also for critically ill patients considered to be at low risk for bleeding.