Regional anticoagulation with trisodium citrate is an effective form of anticoagulation for continuous renal replacement therapy (CRRT) for patients with high risk of bleeding complications and/or with contraindications to heparin. However, this technique is not used currently because of the metabolic complications, requiring specialized dialysis solution. We therefore evaluated the efficacy and safety of a simplified protocol for citrate regional anticoagulation in 22 critically ill patients treated by continuous venovenous hemodiafiltration (CVVHD).

A.C.D-A541 (Lab. BRAUN) solution containing 112.9 mmol/l of trisodium citrate (3.22%) was initially delivered at 250 ml/hour (mean, 251 ± 27 ml/hour) via the prefilter port of a COBE PRISMA with an AN-69 dialyzer, with the rate adjusted to maintain a post-filter ionized calcium (iCa⁺⁺) between 0.3 and 0.4 mmol/l. Plasmatic iCa⁺⁺ was maintained > 1.1 mmol/l by the infusion of calcium chloride (Calcium element concentration was 45.7 mmol/l) at the mean rate of 1.82 ± 0.36 mmol/hour. The blood flow rate was 100 ml/min. Replacement solution (Hemosol^® Solution containing, Na⁺ = 144 mmol/l; HCO₃^- = 35 mmol/l; CA⁺⁺ = 1.75 mmol/l) was delivered at 1000 ml/hour. Dialysate was a modified Hemosol^® Solution (containing, Na⁺ = 126 mmol/l; HCO₃^-= 17 mmol/l; CA⁺⁺ = 1.75 mmol/l) and was also delivered at 1000 ml/hour. Each seance was scheduled for 48 hours. We assessed the serum pH, serum bicarbonate, serum and post-filter iCa⁺⁺ levels every 6 hours.

Mean dialyzer survival was 39 ± 11 hours (median, 41.5 hours). Clotting of the dialyzer was observed in four cases (13 hours; 16 hours; 18 hours and 40 hours). CVVHD was stopped voluntarily in nine patients, without technical problems (median survival was 39 hours). The mean IGS-II score was 69± 12. There were neither bleeding events nor coagulation parameters modifications. Serum sodium, serum pH and serum bicarbonate were similar before and after CVVHD (respectively, 133± 8 vs 133 ± 7 mmol/l, P > 0.05; 7.39 ± 0.15 vs 7.38 ± 0.13, P > 0.05; 25.3 ± 5.5 vs 25.1 ± 6.1, P > 0.05).

Simplified 3.22% trisodium citrate regional anticoagulation for CRRT is efficacy and is not associated with bleeding complications or citrate toxicity.