Prevention of Citrate Toxicity in CRRT

Monitoring Requirements for Citrate Anticoagulation

Frequent measurements of post-filter and serum-ionized calcium should be performed to appropriately titrate the dose of citrate and calcium replacement solutions, as recommended by the Kidney International guidelines 1, 2
Regular monitoring of systemic acid-base balance is advisable, particularly in patients at high risk for citrate accumulation, with a strength of evidence supported by Kidney International 2, 3
Monitoring of serum sodium levels is necessary to prevent hypernatremia, which can occur with citrate anticoagulation, according to the American Journal of Kidney Diseases 4, 5

Patients with severely impaired liver function require cautious use of citrate anticoagulation due to reduced citrate metabolism, as stated by the American Journal of Kidney Diseases 4, 5
Patients with shock and muscle hypoperfusion need careful monitoring but are not absolute contraindications for citrate use, with evidence from the American Journal of Kidney Diseases 4, 5
In liver failure patients, citrate accumulation can be tracked by following systemic ionized calcium levels, as recommended by the American Journal of Kidney Diseases 5

Implement a strict protocol for citrate anticoagulation with adequate staff education to avoid prescription errors, as advised by the American Journal of Kidney Diseases 4, 5
Use dialysate and replacement fluids with appropriate electrolyte composition, particularly with increased magnesium concentration when using regional citrate anticoagulation, according to Clinical Nutrition 6, 7, 8
Ensure the protocol details the infusion rates of citrate and calcium, composition of dialysate and replacement fluid, and intensity of metabolic monitoring, as recommended by the American Journal of Kidney Diseases 4, 5

Use dialysis solutions containing potassium, phosphate, and magnesium to prevent electrolyte disorders during CRRT, as suggested by Clinical Nutrition 6, 7, 8
Commercial CRRT solutions enriched with phosphate, potassium, and magnesium are widely available and can be safely used with regional citrate anticoagulation, according to Clinical Nutrition 7, 8
Prevention of CRRT-related electrolyte derangements by modulating fluid composition is more appropriate than intravenous supplementation, with evidence from Clinical Nutrition 7, 8
Monitor for common electrolyte abnormalities associated with CRRT including hypophosphatemia, hypokalemia, and hypomagnesemia, as recommended by Clinical Nutrition 6, 7
Pay particular attention to magnesium levels, as magnesium can be lost in the effluent as magnesium-citrate complexes during regional citrate anticoagulation, according to Clinical Nutrition 6, 7, 8

The Kidney Disease: Improving Global Outcomes (KDIGO) guidelines suggest using regional citrate anticoagulation rather than heparin in CRRT patients who lack contraindications for citrate (Grade 2B recommendation) 9
The KDIGO guidelines recommend regional citrate anticoagulation over heparin-based anticoagulation for continuous renal replacement therapy (CRRT) in critically ill patients without contraindications, as it provides superior filter patency with minimal bleeding risk 9
The choice of anticoagulation must be determined by patient bleeding risk and coagulation status, presence of citrate contraindications, local institutional expertise and nursing comfort, and availability of appropriate citrate solutions and monitoring protocols 9, 10, 11

Severely impaired liver function and shock with muscle hypoperfusion are listed as major contraindications by KDIGO, but the Canadian Society of Nephrology clarifies these should be considered relative rather than absolute contraindications 12, 13
In liver failure, citrate accumulation can be tracked by monitoring systemic ionized calcium levels and the total calcium-to-ionized calcium ratio 12, 13
In septic shock, multiple randomized controlled trials have demonstrated safety of regional citrate anticoagulation even in severe septic shock 12, 13

A strict protocol with adequate staff education must be in place before introducing regional citrate anticoagulation to avoid prescription errors leading to metabolic complications 12, 13
The protocol must detail infusion rates of citrate and calcium, composition of dialysate and replacement fluid, and intensity of metabolic monitoring including acid-base status, serum sodium, and total/ionized calcium levels 12, 13

Hypernatremia, metabolic alkalosis, and hypocalcemia can be controlled without clinical consequences using a strict protocol 12, 13

Because citrate is not FDA-approved for CRRT anticoagulation and commercially available solutions are hypertonic blood banking products, citrate cannot be universally recommended over heparin in the United States until standardized protocols are created and appropriate citrate solutions are developed and approved 10, 11