Effect of Nephral 400 ST Dialysis Membrane on Coagulation in Hemodialysis

A Comparing Study of Nephral 400 ST and Fx8 Dialysis Membranes on Coagulation During Hemodialysis

The purpose of this study is to investigate whether the dialysis filter AN69ST (Nephral 400 ST Dialysis Membrane) induces less clotting during hemodialysis than a conventional polysulphone filter. Our hypothesis is that the two filters induce the same degree of clotting.

Six consecutive hemodialysis (HD) sessions are evaluated per patient, altogether 10 - 12 stable HD patients (or at least 48 HD sessions altogether). During these six sessions, AN69ST and Fx8 are used on alternate days. Dalteparin is given intravenously as a single bolus dose at start of HD (50% of the conventional dose). Clinical clotting is evaluated visually each hour of HD after blood draining of the venous air trap: 1=no clot, 2=a fibrinous ring, 3=a clot <1 cm, 4=a clot >1 cm and 5=coagulated system (stop in HD).

Blood specimens are taken at start and after each hour of HD. Markers of coagulation (prothrombin 1+2) and of platelets (beta-thromboglobulin) are evaluated as well as anti FXa-activity.

The two filters are going to be compared statistically with respect to the degree of clinical clotting and of intravascular coagulation and platelets activation.

Inclusion Criteria:

• patient aged 18 years or more having been in chronic HD for at least 1 month
• dialysis time at least 4 hours 3 times per week
• blood flow at least 200 ml/min
• Fragmin dose unchanged the last week before study start
• Fragmin given intravenously as one single dose at HD start
• Haemoglobin >= 11.0 g/dL and stable +/- 20% the last week before study start
• erythropoietin and iron dose unchanged the last week before study start
• written and orally informed consent given by the patient

Exclusion Criteria:

• treatment with acetylsalicylic acid (ASA)
• use of Warfarin or another oral anticoagulant
• clinical signs of infection
• disseminated malignant disease