Objective: Citrate anticoagulation is an excellent alternative to heparin anticoagulation for critically ill patients requiring continuous renal replacement therapy. In this article, we provide a safe and an easy-to-handle citrate anticoagulation protocol with variable treatment doses and excellent control of the acid-base status.
Design: Prospective observational study.
Setting: University hospital.
Patients: One hundred sixty-two patients with acute renal failure requiring renal replacement therapy were enrolled in the study.
Intervention: A continuous venovenous hemodialysis-based citrate anticoagulation protocol using a 4% trisodium solution, a specially designed dialysate fluid, and a continuous calcium infusion were used. The study period was 6 days. Hemofilters were changed routinely after 72 hours of treatment. The patients were grouped according to body weight, with patients below 60 kg body weight in group 1, patients with at least 60 kg and up to 90 kg body weight in group 2, and patients with a body weight of above 90 kg in group 3. Dialysate flow was adapted according to body size and matched approximately 2 L/hr for a patient with average body size. Blood flow, citrate flow, and calcium flow were adjusted according to the dialysate flow used.
Measurements and main results: Median filter run time was 61.5 hours (interquartile range: 34.5-81.1 hours). Only 5% of all hemofilters had to be changed because of clotting. The prescribed treatment dose was achieved in all patients. Acid-base and electrolyte control were excellent in all groups. In the rare cases of metabolic disarrangement during citrate anticoagulation, acid-base values were rapidly corrected by modifying either the dialysate flow or alternatively the blood flow rate. Eight patients (5%) developed signs of citrate accumulation indicated by an increase of the total calcium >3 mmol/L or a need for high calcium substitution.
Conclusions: We provide a safe and an easy-to-handle citrate anticoagulation protocol that allows an excellent acid-base and electrolyte control in critically ill patients with acute renal failure. The protocol can be adapted to patients' need, allowing a wide spectrum of treatment doses.