Simplified method of regional citrate anticoagulation for continuous extra renal epuration

Background

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).

Methods

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.

Results

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).

Conclusion

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