This study is an unblinded pilot RCT designed to test the feasibility of conducting a subsequent large scale study that will assess whether CVVH leads to improved patient outcomes (ie, survival, renal recovery) as compared to CVVHD. Although we will be collecting the full array of patient-relevant data for up to 60 days following randomization, the main purpose of this pilot study is to demonstrate the feasibility of recruiting, treating and following patients for a study designed to test this hypothesis.