Condition category
Injury, Occupational Diseases, Poisoning
Date applied
06/03/2012
Date assigned
01/05/2012
Last edited
19/09/2014
Prospective/Retrospective
Prospectively registered
Overall trial status
Completed
Recruitment status
No longer recruiting

Plain English Summary

Background and study aims
Dialysis removes substances from the blood to avoid uremia - a syndrome that intoxicates the patient by the accumulation of compounds that are usually excreted in the urine. There are more than 4000 of such substances but we currently measure only a few of them. Special filters in dialysis machines that allow those substances to be removed from the blood to the dialysate, the ‘water’ that is used to wash the blood. These dialysis membranes usually only allow small substances to travel from the blood of the patient to the dialysate, such as urea, sodium, potassium and phosphorus. Bigger molecules can only be removed from the blood by dialysis membranes with a larger pore size. Hence, there might be a disadvantage in using large pores as the patient would lose important proteins like albumin. The aim of our study was to compare two dialyzers (the AV 1000S and the EMiC2) in their ability to eliminate small and bigger molecules. Both dialyzers are equal in membrane surface area and membrane material, but differ in their membrane pore size. The EMiC2 dialyzer has a larger pore size than the AV 1000S. We further aimed to investigate whether the dialyzer with the larger pore size would leak albumin.

Who can participate?
Every critically ill patient over the age of 18 with acute kidney injury undergoing extended dialysis with the GENIUS 90 system.

What does the study involve?
Every patient received two consecutive extended dialysis sessions starting in a random order with either the EMiC2 or the Ultraflux AV 1000S filter, followed by a treatment with the other dialyser. Levels of the molecules beta2-microglobulin, cystatin c, albumin, creatinine and urea were measured before and after 0.5, 5.0 and 10 hours of dialysis.

What are the possible benefits and risks of participating?
Dialysis with highly permeable membranes could lead to a mild protein loss which in itself does not present an increased medical risk. We monitored every patient’s nutritional status carefully and tailored the individual nutrition to the patient’s need. There might be a benefit of removing larger substances from the blood of critically ill patients but the potential effect, if existent, will not be of clinical importance for the individual patient.

Where is the study run from?
The intensive care units of the Hannover Medical School (Germany).

When is the study starting and how long is it expected to run for?
Patients were enrolled between May 2009 and May 2012.

Who is funding the study?
Investigator-initiated trial.

Who is the main contact?
Jan T Kielstein
Kielstein@yahoo.com

Trial website

Contact information

Type

Scientific

Primary contact

Prof Jan T Kielstein

ORCID ID

Contact details

Department of Nephrology and Hypertension
Medical School Hannover
Carl-Neuberg-Str. 1
Hannover
30625
Germany

Additional identifiers

EudraCT number

ClinicalTrials.gov number

Protocol/serial number

Hannover Medical School, Germany, protocol # 5307

Study information

Scientific title

Comparison of middle molecule clearance and removal between a new high cut-off dialyzer to an established dialyzer - a clinical cross-over comparison in extended dialysis

Acronym

Study hypothesis

We aimed to evaluate the efficiency of a new dialyzer comprised of a new polysulfone membrane and a bigger pore size in regard to its ability to eliminate beta-2 microglobulin (molecular weight 11.8 kDa), an excellent surrogate for middle molecules as well as its properties in terms of albumin (molecular weight 65 kDa) loss.

Ethics approval

Hannover Medical School, Germany, 27/04/2009, ref: 5307

Study design

Randomized cross-over comparison

Primary study design

Interventional

Secondary study design

Randomised controlled trial

Trial setting

Hospitals

Trial type

Treatment

Patient information sheet

Not available in web format, please use the contact details below to request a patient information sheet

Condition

Acute kidney injury, renal replacement therapy

Intervention

In this prospective randomized cross-over trial every participating patient received two consecutive extended dialysis sessions starting in random order either with the EMiC2 or the Ultraflux AV 1000S dialyser followed by a treatment with the other dialyser. The duration of treatment for each patient was two days.

Intervention type

Other

Phase

Not Applicable

Drug names

Primary outcome measures

1. Dialyser clarance of middle molecules
2. Total amount of middle molecules in the combined spent dialysate and ultrafiltrate dialyzer clearance measured 30 min after start of treatment for the quantified substances according to equation 1 using the patients’ hematocrit level (Hct) at the time of clearance sampling.
Eq. 1: Kplasma = QB x (1 – Hct/100) x ((Cart – Cven)/Cart)
3. Reduction ratio (RR) determined for beta2-microglobulin, creatinine, cystatin c and urea. Therefore, blood samples will be collected right before the start (Cpre) as well as at the end (Cpost) of the treatment. Calculations of RR executed according to equation 2.
Eq. 2: RR = (Cpost – Cpre)/Cpre x 100
Samples of the total spent dialysate will be drawn at the end of the treatment.

Secondary outcome measures

Albumin loss
Total loss of albumin by adding the albumin values in the total spent dialysate and ultrafiltrate. For concentrations below the detection limit of 1.1 mg/dl, an albumin concentration of 1.1 mg/dl was assumed.
Eq. 3: Alb = Calb(dialysate) x Vdialysate + Calb(ultrafiltrate) x Vultrafiltrate

Overall trial start date

01/05/2012

Overall trial end date

01/05/2012

Reason abandoned

Eligibility

Participant inclusion criteria

1. Males and females
2. Aged > 18 years
3. Patients in the intensive care unit suffering from acute kidney injury [stage Acute Kidney Injury Network (AKIN) III], i.e. need for renal replacement therapy
4. Treatment using the 90 L GENIUS batch dialysis system
5. Signed consent

Participant type

Patient

Age group

Adult

Gender

Both

Target number of participants

11

Participant exclusion criteria

1. Pregnant and nursing patients
2. Patients participating in a different study (other than observational)
3. All conditions deemed to justify exclusion by the recruiting physician

Recruitment start date

01/05/2012

Recruitment end date

01/05/2012

Locations

Countries of recruitment

Germany

Trial participating centre

Department of Nephrology and Hypertension
Hannover
30625
Germany

Sponsor information

Organisation

Medical School Hannover (Germany)

Sponsor details

c/o Prof Jan T Kielstein
Department of Nephrology and Hypertension
Carl-Neuberg-Str. 1
Hannover
30625
Germany

Sponsor type

University/education

Website

http://www.mh-hannover.de

Funders

Funder type

Industry

Funder name

Fresenius Medical Care (Germany)

Alternative name(s)

Funding Body Type

Funding Body Subtype

Location

Results and Publications

Publication and dissemination plan

Not provided at time of registration

Intention to publish date

Participant level data

Not provided at time of registration

Results - basic reporting

Publication summary

Publication citations

Additional files

Editorial Notes