Original Article Citrate anticoagulation using ACD solution A during long-term haemodialysis STEPHEN WRIGHT, 1 ULI STEINWANDEL 1 and PAOLO FERRARI 1,2 1 Department of Nephrology, Fremantle Hospital, and 2 School of Medicine and Pharmacology, University of Western Australia, Perth, Western Australia, Australia KEY WORDS: anticoagulation, bleeding, citrate, haemodialysis, heparin, protocol. Correspondence: Professor Paolo Ferrari, Department of Nephrology, Fremantle Hospital, Alma Street, Perth, WA 6160, Australia. Email: paolo.ferrari@health.wa.gov.au Accepted for publication 17 October 2010. Accepted manuscript online 3 November 2010. doi:10.1111/j.1440-1797.2010.01421.x SUMMARY AT A GLANCE This study documents that the use of citrate anticoagulation with acid citrate dextrose solution A (ACDA) is a safe and efficient alternative in haemodialysis patients when conventional or fractioned heparin is contraindicated. To maintain a post-filter ionized calcium of 0.2–0.3 mmol/L the ACDA infusion rate should be 350 mL/h, as there is an increased risk of clotting at 300 mL/h. It is important that the ionized calcium is monitored and replaced with i.v. calcium to prevent systemic hypocalcaemia. ABSTRACT: Aim: Haemodialysis with regional citrate anticoagulation in patients with contraindications for heparin is increasingly performed in the USA and Europe. Most published protocols use trisodium citrate, which is not readily available nor is it licensed in Australia. We established a protocol for citrate- anticoagulation in haemodialysis using acid citrate dextrose solution A (ACDA), which is approved for apheresis procedures in Australia. The aim of the present study was to assess the safety and efficacy of this protocol for routine use in haemodialysis patients. Methods: Systemic and post-filter blood ionized calcium, serum sodium and bicarbonate and dialyzer clotting score were analyzed prospectively in 14 patients undergoing 150 consecutive haemodialysis treatments with citrate anticoagulation using calcium-free dialysate. A simple algorithm allowed the attending nurse to adjust citrate infusion (to maintain post-filter ionized calcium at 0.2–0.3 mmol/L) and i.v. calcium substitution. Scheduled dialysis time was 4 h, and point-of-care monitoring of blood ionized calcium during dialysis was done at 0, 15, 60, 120 and 240 min. Results: ACDA infusion rates of 300 mL/h were used in the first 52 treat- ments, but resulted in high dialyzer clotting score and 6% of treatments were discontinued due to complete clotting. Thereafter, ACDA infusion rate was increased to 350 mL/h, with all 98 subsequent treatments completed successfully. Ionized calcium levels were stable during all procedures with post-dialysis serum sodium averaging 135 1 3 mmol/L and bicarbonate 23.8 1 2 mmol/L. Conclusion: Routine use of citrate anticoagulation in the setting of a long- term haemodialysis unit is safe and efficient. Point-of-care measurements of ionized calcium levels are critical to safely and successfully perform citrate anticoagulation. During haemodialysis, anticoagulation with heparin is required to prevent thrombus formation in the extracorpo- real circuit. 1,2 Patients at increased risk of bleeding or with heparin-induced thrombocytopenia (HIT) type II are often dialyzed without heparin, 3,4 which requires repeated flush- ing of blood lines and dialyzer and thus it is wasteful of nursing time, may result in shorter haemodialyzer life and in reduced adequacy of dialysis. Therefore, alternative methods of extracorporeal anticoagulation without systemic effect are desirable. Regional (extracorporeal) anticoagulation with citrate during haemodialysis was introduced in 1961 by Morita et al., 5 but it found few applications in clinical practice because of the risk of citrate-induced metabolic alkalosis or hypocalcaemia and a lack of technical support requirements necessary to prevent these metabolic complications. 6,7 With the introduction of modern treatment and monitoring devices in dialysis it has become possible to safely and suc- cessfully reintroduce regional citrate anticoagulation, 8–11 in which anticoagulation occurs in the extracorporeal circula- tion when sodium citrate is infused through the heparin connection of the arterial line. Citrate binds free calcium, thus preventing activation of blood coagulation. Calcium chloride is added after the venous chamber and air trap to restore normal calcium concentration, therefore reversing Nephrology 16 (2011) 396–402 © 2011 The Authors Nephrology © 2011 Asian Pacific Society of Nephrology 396