Regional Citrate Anticoagulation for Intermittent Hemodialysis in Dogs

BACKGROUND: The traditional systemic heparinization used for anticoagulation in extracorporeal therapies may cause fatal complications in animals at risk of bleeding. HYPOTHESIS/OBJECTIVES: To develop and validate a protocol of regional citrate anticoagulation (RCA) for intermittent hemodialysis in dogs. ANIMALS: A total of 172 dogs treated with hemodialysis for acute kidney injury. METHODS: In vitro titration was performed, adding trisodium citrate and calcium chloride to heparinized canine blood. A tentative protocol was used first in 66 treatments with additional heparinization and subsequently in 518 heparin‐free treatments. Safety and adequacy of RCA were assessed based on clinical and laboratory monitoring, dialyzer pressure gradient, treatment completion, and visual scoring of the extracorporeal circuit. RESULTS: Addition of 1 mmol/L citrate to heparinized blood decreased the ionized calcium concentration by 0.23 mmol/L (95% confidence interval [CI], 0.16–0.30) and 1 mmol/L calcium increased it by 0.62 mmol/L (95% CI, 0.45–0.79). Heparin‐free treatments were initiated with infusion of trisodium citrate (102 mmol/L) at 2.55 mmol/L blood and calcium chloride (340 mmol/L) at 0.85 mmol/L. Citrate and calcium administrations were adjusted in 27 and 34% of the treatments, respectively. Overall, anticoagulation was satisfactory in 92% of the treatments, with expected azotemia reduction in 95% (urea) and 86% (creatinine), stable dialyzer pressure gradient in 82%, and clean extracorporeal circuits in 92% of the treatments. Eighteen treatments (3.5%) were discontinued prematurely, 9 because of clotting and 9 for reasons unrelated to the RCA procedure. CONCLUSIONS AND CLINICAL IMPORTANCE: Regional citrate anticoagulation allows safe and efficient heparin‐free hemodialysis in dogs at risk of bleeding.