From the Guidelines
Regional citrate anticoagulation is preferred over heparin in CRRT due to its lower risk of bleeding and ability to prolong filter life, as supported by recent guidelines. The use of regional citrate anticoagulation (RCA) in continuous renal replacement therapy (CRRT) has been shown to offer several advantages over heparin, including reduced bleeding complications and longer filter life 1. RCA works by infusing citrate into the circuit pre-filter, which chelates calcium and inhibits clotting locally within the extracorporeal circuit, while systemic anticoagulation is avoided.
Some key benefits of RCA include:
- Reduced bleeding risk since anticoagulation is confined to the circuit
- Ability to use it in patients with heparin-induced thrombocytopenia
- Longer filter life, often 72+ hours versus 24-48 hours with heparin However, RCA requires careful monitoring of ionized calcium levels, pH, and electrolytes to avoid complications like metabolic alkalosis, citrate accumulation, or hypocalcemia 1.
The main limitations of RCA include increased complexity of the protocol, need for frequent monitoring, and contraindication in patients with severe liver dysfunction who cannot metabolize citrate effectively. Despite these considerations, the most recent guidelines suggest regional citrate rather than heparin or other non-heparin anticoagulants due to its similar efficacy and superior safety compared with heparin in patients without a history of HIT 1. Therefore, regional citrate anticoagulation should be considered the first-line anticoagulation method for CRRT when there are no contraindications.
From the Research
Advantages of Regional Citrate Anticoagulation
- Reduced risk of circuit loss compared to regional and systemic heparin 2
- Lower incidence of filter failure 2, 3
- Decreased bleeding risk compared to systemic heparin 2, 3, 4
- Lower risk of heparin-induced thrombocytopenia (HIT) 2, 3
- Longer filter life span 3, 5
Comparison with Heparin Anticoagulation
- Citrate anticoagulation has a similar efficacy to heparin anticoagulation for CRRT 4
- Heparin may increase the risk of bleeding, particularly in critically ill patients 4, 6
- Citrate anticoagulation may cause hypocalcemia and metabolic disturbances, but these can be managed with proper use 2, 3, 4, 6
Clinical Implications
- Regional citrate anticoagulation should be considered a better anticoagulation method than heparin for CRRT in critically ill patients without any contraindication 2, 3
- Citrate anticoagulation may have benefits in terms of patient and kidney survival, but this needs to be confirmed in larger randomized controlled multicenter trials 6
- The use of citrate may be associated with less inflammation and has useful bio-energetic implications 6