<qa>  What is the primary endpoint of the research proposal?In the first part of the research proposal concerning high bleeding risk patients a comparison will be made in a prospective sequential cohort study between no anticoagulation and citrate regarding filter survival time, bleeding risk, dialyser efficacy, circulating immune mediators such as neutrophil elastase and myeloperoxidase, interleukins, platelet-activating factors, activated complement products, soluble cytokine receptors and adhesion molecules, metabolic balance, and acute renal failure duration. Also, filter survival time will be assessed. The purpose of the second part of the current research proposal is to evaluate in a randomised controlled clinical trial in 350 critically ill patients 18-80 years with acute renal failure, 2 arms of 175 patients, without an increased bleeding risk thrombocytes 40 x 109L, APTT 60 sec, PT-INR 2 whether citrate CVVH is better than bicarbonate-heparin CVVH in terms of the same parameters as in the first part of the study but with the addition of mortality as the primary endpoint. 