Evaluation Of Acid-Base Control, Electrolyte Balance, And Filter Patency Of A Prismaflexbased Regional Citrate Anticoagulation Protocol For Pre-Dilution Continuous Veno-Venous Hemodiafiltration

Background: Regional citrate anticoagulation (RCA) is increasingly used in patients requiring continuous renal replacement therapy (CRRT). This study evaluated a new RCA protocol based on the Prismaflex (R) dialysis device and an isotonic citrate solution (prismocitrate) for pre-dilution continous veno-venous hemodiafiltration. Methods: The Prismaflex (R)/Prismocitrate-based protocol involved an AN69ST (R) membrane (Prisma Flex ST100), a blood flow of 120 mL/min, 1.8 L/h Prismocitrate (10 mmol/L citrate/2 mmol/L citric acid) substitution fluid in pre-dilution mode, and 0.8 L/h dialysate flow (PrismOcal) at the start. In parallel, infusions of potassium, calcium, and magnesium were initiated. Blood pH, bicarbonate, base excess, and ionized calcium levels were measured in 6 hours intervals and magnesium levels every 24 hours. Scheduled hemofilter run time was 72 hours. Results: A consecutive series of 25 continuous renal replacement treatments was analyzed in 15 patients. After at least 6h of RRT, 69.9% of bicarbonate concentrations and 84.6% base excess (BE) calculations were below normal range. During CRRT, mean bicarbonate decreased from 22.9 to 20.2 mmol/L and mean BE from -1.5 to -4.2 mmol/L. In addition, 66.3% of ionized systemic calcium concentrations were out of the normal range, while 54.1% of the magnesium readings were above normal range. Five filters reached the scheduled run time of 72 hours, 19 treatments stopped prematurely because of RRT related reasons (5 filter clottings, 2 severe metabolic disarrangements, 12 major Prismaflex (R) hardware or software handling problems). One patient was switched to intermittent hemodialysis. Conclusions: The evaluated Prismaflex (R)/ Prismocitrate-based citrate anticoagulation protocol provides insufficient control of blood acid-base and electrolyte balance.