Heparin versus citrate for anticoagulation in critically ill patients treated with continuous renal replacement therapy

Background: Continuous renal replacement therapy (CRRT) is commonly used in the care of critically ill patients (Gabutti et al., 2002). Critical illness increases the likelihood to both coagulation and bleeding, making anticoagulation for CRRT problematic. Aims: This mini-review aims to examine the evidence that compares the use of systemic heparin and regional citrate as forms of anticoagulation for CRRT in critically ill patients. The primary outcome of interest was haemofilter circuit survival, and the secondary outcome was reduced risk of bleeding. Search strategy: A systematic literature search was undertaken to identify all studies comparing these drugs. The Cochrane Library, Medline and Embase databases were searched. Eighty-nine articles were found. Included studies were randomized controlled trials (RCTs), which used a target population of critically ill adults. Studies were excluded if they had not been written in English and if they were not available through King's College London. After applying the inclusion and exclusion criteria, three RCTs comparing the use of systemic heparin and regional citrate were included in the review. Results: Two studies showed significant differences in circuit survival time, with citrate prolonging survival time. All studies showed an increased risk of bleeding in the heparin group, resulting in a higher rate of transfusion while heparin was being used. Conclusions: The studies examined lacked reference to the power of the studies and strength in the presentation of the results. Because of the lack of reliability in the studies, it would be suggested that further research is needed on this topic in order to produce rigorous high-quality reviews with limited bias. The use of citrate, as with all treatments in clinical practice, should be used with caution and assessed on an individual patient basis. Reviewing this evidence helps to gain an insight into different treatment options available, identifying some of the risks and benefits.