Regional citrate anticoagulation for continuous renal replacement therapy without post-filter monitoring of ionized calcium

Continuous renal replacement therapy (CRRT) modalities are usually preferred in hemodynamically unstable patients in the intensive care units (ICU) but perceived expense and complexity slows broad acceptance. Heparin remains a problematic choice for CRRT anticoagulation due to the risk of bleeding in ICU patients and concerns about heparin-induced thrombocytopenia. In this paper, we are describing our simplified regional citrate anticoagulation protocol, utilizing commercially available, premixed solutions exclusively and minimized laboratory monitoring. The protocol is employing Anticoagulant Citrate Dextrose-A (ACD-A) solution for citrate delivery, calcium-free dialysate or replacement fluids and separate calcium infusion, all commercially available in the United States. ACD-A is being infused pre-filter with an hourly rate of 1.5:1 to blood flow rate per minute without specific monitoring of post-filter ionized calcium concentration. Separate infusions of calcium-chloride, sodium phosphate and magnesium chloride are employed via triple lumen catheter to normalize peripheral ionized calcium, phosphate and magnesium concentrations, respectively. The protocol can be conveniently applied in both continuous veno-venous hemofiltration and hemodiafiltration regimens with several of the commercially available CRRT platforms. Built-in features of the protocol are the tendency alkalization and mild hypernatremia, which may be advantageous under select circumstances.