A novel citrate anticoagulation regimen for continuous venovenous hemodiafiltration

Abstract

Objective

Validation of a novel citrate anticoagulation regimen for continuous venovenous hemodiafiltration (CVVHDF).

Design and setting

Prospective cohort trial in medicosurgical intensive care units of two university-affiliated teaching institutions.

Patients

Participants were patients at high risk for bleeding, with renal failure requiring CVVHDF without heparin. Fourteen patients completed the study.

Intervention

A convection-based citrate anticoagulation CVVHDF regimen using an isotonic replacement fluid containing citrate administered in predilution. A neutralizing solution of calcium chloride and magnesium sulfate was infused at the end of the circuit. Blood flow rate was set and kept at 125 ml/min, and the flow rate of the replacement fluid was initiated at 1250 ml/h and adjusted thereafter according to the monitoring of blood activated coagulation time (ACT), with a target between 180 to 220 s.

Measurements and results

The average filter time-life was 44 h. Thrombosis of the proximal portion of the circuit (which was not anticoagulated) was the main reason for technique failure. A mean urea clearance of 21 ml/min was obtained. Electrolytes and acid-base balance were both well maintained. Six percent (16/287) of Ca_i readings less than 0.3 mmol/l were associated with very high ACT levels (>300 s).

Conclusions

This regimen is shown to be safe, efficacious, and convenient. Citrate anticoagulation should be monitored using postfilter ACT and/or ionized calcium with respective targets of 200–250 s or 0.3–0.4 mmol/l.