Myoglobin clearance with continuous veno-venous hemodialysis using high cutoff dialyzer versus continuous veno-venous hemodiafiltration using high-flux dialyzer: a prospective randomized controlled trial.

BACKGROUND: Myoglobin clearance in acute kidney injury requiring renal replacement therapy is important because myoglobin has direct renal toxic effects. Clinical data comparing different modalities of renal replacement therapy addressing myoglobin clearance are limited. This study aimed to compare two renal replacement modalities regarding myoglobin clearance. METHODS: In this prospective, randomized, single-blinded, single-center trial, 70 critically ill patients requiring renal replacement therapy were randomized 1:1 into an intervention arm using continuous veno-venous hemodialysis with high cutoff dialyzer and a control arm using continuous veno-venous hemodiafiltration postdilution with high-flux dialyzer. Regional citrate anticoagulation was used in both groups to maintain the extracorporeal circuit. The concentrations of myoglobin, urea, creatinine, ß2-microglobulin, interleukin-6 and albumin were measured before and after the dialyzer at 1 h, 6 h, 12 h, 24 h and 48 h after initiating continuous renal replacement therapy. RESULTS: Thirty-three patients were allocated to the control arm (CVVHDF with high-flux dialyzer) and 35 patients to the intervention arm (CVVHD with high cutoff dialyzer). Myoglobin clearance, as a primary endpoint, was significantly better in the intervention arm than in the control arm throughout the whole study period. The clearance values for urea and creatinine were higher in the control arm. There was no measurable albumin clearance in both arms. The clearance data for ß2-microglobulin and interleukin-6 were non-inferior in the intervention arm compared to those for the control arm. Dialyzer lifespan was 57.0 [38.0, 72.0] hours in the control arm and 70.0 [56.75, 72.0] hours in the intervention arm (p = 0.029). CONCLUSIONS: Myoglobin clearance using continuous veno-venous hemodialysis with high cutoff dialyzer and regional citrate anticoagulation is better than that with continuous veno-venous hemodiafiltration with regional citrate anticoagulation. TRIAL REGISTRATION: German Clinical Trials Registry (DRKS00012407); date of registration 23/05/2017. https://www.drks.de/drks_web/navigate.do?navigationId=trial.HTML&TRIAL_ID=DRKS00012407 .

Middle molecule clearance with high cut-off dialyzer versus high-flux dialyzer using continuous veno-venous hemodialysis with regional citrate anticoagulation: A prospective randomized controlled trial.

BACKGROUND: Regional anticoagulation with citrate during renal replacement therapy (RRT) reduces the risk of bleeding, extends dialyzer lifespan and is cost-effective. Therefore, current guidelines recommend its use if patients are not anticoagulated for another reason and if there are no contraindications against citrate. RRT with regional citrate anticoagulation has been established in critically ill patients as continuous veno-venous hemodialysis (CVVHD) to reduce citrate load. However, CVVHD is inferior regarding middle molecule clearance compared to continuous veno-venous hemofiltration (CVVH). The use of a high cut-off dialyzer in CVVHD may thus present an option for middle molecule clearance similar to CVVH. This may allow combining the advantages of both techniques. METHODS: In this prospective, randomized, single-blinded single-center-trial, sixty patients with acute renal failure and established indication for renal replacement therapy were randomized 1:1 into two groups. The control group was put on CVVHD using regional citrate anticoagulation and a high-flux dialyzer, while the intervention group was on CVVHD using regional citrate anticoagulation and a high-cut-off dialyzer. The concentrations of urea, creatinine, ß2-microglobulin, myoglobin, interleukin 6 and albumin were measured pre- and post-dialyzer 1, 6, 12, 24 and 48 hours after initiating CVVHD. RESULTS: Mean plasma clearance for ß2-microglobulin was 19.6±5.8 ml/min in the intervention group vs. 12.2±3.6 ml/min in the control group (p<0.001). For myoglobin (8.0±4.5 ml/min vs. 0.2±3.6 ml/min, p<0.001) and IL-6 (1.5±4.3 vs. -2.5±3.5 ml/min, p = 0.002) a higher mean plasma clearance using high-cut-off dialyzer could be detected too, but no difference for urea, creatinine and albumin could be observed concerning this parameter between the two groups. CONCLUSION: CVVHD using a high cut-off dialyzer results in more effective middle molecule clearance than that with high-flux dialyzer. TRIAL REGISTRATION: German Clinical Trials Register (DRKS00005254, registered 26th November 2013).