Does the surface-treated AN69 membrane prolong filter survival in CRRT without anticoagulation?

The need for continuous anticoagulation remains a significant drawback in continuous renal replacement therapy (CRRT), especially in patients with increased bleeding risk. Polyethyleneimine treatment of the AN69 membrane (AN69ST) reduces thrombogenicity through decreased contact activation and promotion of heparin binding. The aim of this study is to evaluate whether this membrane prolongs filter survival in CRRT without anticoagulation. A single-center, prospective, randomized, double-blind controlled trial with cross-over design comparing filter survival with the AN69ST membrane and the original AN69 membrane in 39 patients treated with continuous venovenous hemofiltraton (CVVH) without additional heparin. Filter survival with the AN69ST membrane (n = 75) was 14.2 +/- A 8.2 h, which is not significantly different from the 13.3 +/- A 10.3 h for the original AN69 membrane (n = 76; p = 0.59). Limiting the analysis to those treatments that were interrupted for filter clotting yielded similar results: 14.4 +/- A 8.2 h for the AN69 ST membrane (n = 62) versus 14.1 +/- A 7.5 h for the original AN69 membrane (n = 56) (p = 0.93). Compared with the original AN69 membrane, the surface-treated AN69ST membrane does not prolong filter survival during CVVH without systemic anticoagulation and with the CRRT settings used in this study.