New high-cutoff dialyzer allows improved middle molecule clearance without an increase in albumin loss: a clinical crossover comparison in extended dialysis.

BACKGROUND

Accumulation of middle molecules is thought to have adverse effects in patients with acute kidney injury (AKI). Elimination of middle molecules by non-convective means, i.e. hemodialysis, remains difficult. The aim of the study was to investigate the removal characteristics of a new high permeability membrane in AKI patients undergoing extended dialysis (ED).

PATIENTS AND METHODS

We performed a prospective, crossover study comparing the EMiC2 dialyzer (1.8 m(2), FMC, Germany) and AV 1000S (1.8 m(2), FMC) in 11 critically ill patients with AKI. β2-Microglobulin, cystatin c, creatinine, and urea were measured before and after 0.5, 5.0 and 10 h of ED. Serum reduction ratios, dialyzer clearances, and mass in the total collected dialysate were determined.

RESULTS

Dialyzer clearance of β2-microglobulin (EMiC2: 52 ± 1.7 ml/min, AV 1000S: 41.7 ± 1.5 ml/min, p = 0.0002) and cystatin c (EMiC2: 47.2 ± 1.2 ml/min, AV 1000S: 34.2 ± 2.3 ml/min, p < 0.0001) was markedly different, as was the reduction of serum levels of β2-microglobulin (EMiC2: 54.3 ± 3.6%, AV 1000S: 39.1 ± 4.5%, p = 0.025) and cystatin c (EMiC2: 38.9 ± 2.6%, AV 1000S: 28.0 ± 3.9%, p = 0.043). Additionally, we observed a higher total amount of these substances in the collected dialysate. There was no significant difference in the total amount of albumin eliminated per treatment.

CONCLUSION

The new EMiC2 dialyzer enhances removal of middle molecules without an increase in albumin loss. The clinical relevance of this finding needs to be determined.