title: Regional citrate anticoagulation in CVVH: a new protocol combining citrate solution with a phosphate-containing replacement fluid.
abstract: Regional citrate anticoagulation (RCA) is a valid anticoagulation method in continuous renal replacement therapies (CRRT) and different combination of citrate and CRRT solutions can affect acid-base balance. Regardless of the anticoagulation protocol, hypophosphatemia occurs frequently in CRRT. In this case report, we evaluated safety and effects on acid-base balance of a new RCA- continuous veno-venous hemofiltration (CVVH) protocol using an 18 mmol/L citrate solution combined with a phosphate-containing replacement fluid. In our center, RCA-CVVH is routinely performed with a 12 mmol/L citrate solution and a postdilution replacement fluid with bicarbonate (protocol A). In case of persistent acidosis, not related to citrate accumulation, bicarbonate infusion is scheduled. In order to optimize buffers balance, a new protocol has been designed using recently introduced solutions: 18 mmol/L citrate solution, phosphate-containing postdilution replacement fluid with bicarbonate (protocol B). In a cardiac surgery patient with acute kidney injury, acid-base status and electrolytes have been evaluated comparing protocol A (five circuits, 301 hours) vs. protocol B (two circuits, 97 hours): pH 7.39 ± 0.03 vs. 7.44 ± 0.03 (P < 0.0001), bicarbonate 22.3 ± 1.8 vs. 22.6 ± 1.4 mmol/L (NS), Base excess -2.8 ± 2.1 vs. -1.6 ± 1.2 (P = 0.007), phosphate 0.85 ± 0.2 vs. 1.3 ± 0.5 mmol/L (P = 0.027). Protocol A required bicarbonate and sodium phosphate infusion (8.9 ± 2.8 mmol/h and 5 g/day, respectively) while protocol B allowed to stop both supplementations. In comparison to protocol A, protocol B allowed to adequately control acid-base status without additional bicarbonate infusion and in absence of alkalosis, despite the use of a standard bicarbonate concentration replacement solution. Furthermore, the combination of a phosphate-containing replacement fluid appeared effective to prevent hypophosphatemia.
authors.affiliation: Department of Nephrology and Urology, Hemodialysis Unit, Umberto I, Policlinico di Roma, Sapienza University, Rome, Italy. santo.morabito@uniroma1.it
authors.forename: Santo
authors.initials: S
authors.lastname: Morabito
authors.forename: Valentina
authors.initials: V
authors.lastname: Pistolesi
authors.forename: Luigi
authors.initials: L
authors.lastname: Tritapepe
authors.forename: Laura
authors.initials: L
authors.lastname: Zeppilli
authors.forename: Francesca
authors.initials: F
authors.lastname: Polistena
authors.forename: Enrico
authors.initials: E
authors.lastname: Fiaccadori
authors.forename: Alessandro
authors.initials: A
authors.lastname: Pierucci
mesh_terms: D000368:Aged; D000925:Anticoagulants / Q000008:administration & dosage*; D019343:Citric Acid / Q000008:administration & dosage*; D005260:Female; D005440:Fluid Therapy / Q000379:methods*; D006440:Hemofiltration / Q000379:methods*; D006801:Humans; D010710:Phosphates / Q000008:administration & dosage*
chemical_list: D000925:Anticoagulants; D010710:Phosphates; D019343:Citric Acid; C018279:sodium phosphate