Objective: To compare the efficacy and safety of adjusted-dose unfractionated heparin with that of regional citrate anticoagulation in intensive care patients treated by continuous venovenous hemofiltration (CVVH).
Design and setting: Prospective, randomized, clinical trial in a 32-bed medical and surgical ICU in a university teaching hospital.
Patients: ICU patients with acute renal failure requiring continuous renal replacement therapy, without cirrhosis, severe coagulopathy, or known sensitivity to heparin.
Interventions: Before the first CVVH run patients were randomized to receive anticoagulation with heparin or trisodium citrate. Patients eligible for another CVVH run received the other study medication in a cross-over fashion until the fourth circuit.
Measurements and results: Forty-nine circuits (hemofilters) were analyzed: 23 with heparin and 26 with citrate. The median lifetime of hemofilters was 70 h (interquartile range 44-140) with citrate anticoagulation and 40 h (17-48) with heparin (p=0.0007). One major bleeding occurred during heparin anticoagulation and one metabolic alkalosis (pH=7.60) was noted with citrate after a protocol violation. Transfusion rates (units of red cells per day of CVVH) were, respectively, 0.2 (0.0-0.4) with citrate and 1.0 (0.0-2.0) with heparin (p=0.0008).
Conclusions: Regional citrate anticoagulation seems superior to heparin for the filter lifetime and transfusion requirements in ICU patients treated by continuous renal replacement therapy.