Condition category
Urological and Genital Diseases
Date applied
Date assigned
Last edited
Prospectively registered
Overall trial status
Recruitment status

Plain English Summary

Background and study aims
People who suffer with kidney failure need dialysis treatment 3 times a week. Each dialysis session usually lasts 4 hours, and takes place either in a hospital or in a dedicated unit outside of hospital. Dialysis treatment cleans the blood of toxins that are usually removed by kidneys. As well as removing toxins from blood, dialysis also needs to remove water from blood. One of the jobs of a Kidney Doctor is to determine how much water to remove from the blood during dialysis for each patient. This is difficult to determine and the consequences of getting it wrong can be serious. Removing too much water results in severe dehydration that can cause people to feel faint, collapse, and in extreme cases cause mini strokes. Removing too little water can result in over-hydration, which can lead to heart disease and water on the lungs. At present, there is no perfect way of establishing exactly how much water should be removed from each patient at each dialysis session. The amount removed is based on examining patients, looking for signs of excess fluid or dehydration, including looking at patient’s blood pressure. This process is inexact. This study is to establish whether a simple, quick, and inexpensive blood test, taken from the dialysis machine at each session, can be used to help guide how much water should be removed from each patient during dialysis. Should this blood test work, it will reduce the side effects of patients having too much or too little water removed during dialysis, potentially leading to a better quality of life, and even life expectancy.

Who can participate?
Adults diagnosed with end stage kidney failure

What does the study involve?
Participants are first observed for three dialysis sessions. No changes to their dialysis prescription are made at this time. Measurements taken include ScvO2 (amount of oxygen in the blood), cardiac output (amount of blood pumped out by the heart), and hydration status (to see whether the patient is over or under-hydrated). These measurements are taken before and after dialysis. A quality of life questionnaire is completed at the first session. During the treatment period, patients continue to attend their normal dialysis sessions. Before each dialysis session, they are assessed by a medical member of the trial team. This assessment involves reviewing the ScvO2 after dialysis from their previous dialysis session and examining for any evidence of fluid overload (too much fluid). If the ScvO2 is <65% and there is no evidence of fluid overload, target weight (amount of fluid removed during dialysis) will be increased by 0.5 kg. This continues until either an ScvO2≥65% is achieved, or maximum intervention has been reached. Maximum intervention refers to the point at which clinical examination precludes further increases in target weight due to risk of hypervolaemia (increase in blood volume) despite ScvO2 being <65%. A quality of life questionnaire is completed every third dialysis session during this period. After the intervention period, the participants are observed for the next 12 weeks, where ScvO2, cardiac output measurements and hydration status monitoring are all performed. Quality of life questionnaires are also completed at certain times during this period.

What are the possible benefits and risks of participating?
Monitoring ScvO2 before and after dialysis could potentially provide a means by which to protect against excessive fluid removal that can occur during haemodialysis. Hypovolaemia (decrease in amount of blood) can lead to headaches, cramps, access clotting, and falls. Additionally, hypovolaemia can result in low blood pressure, which is directly linked to increased mortality (death). Therefore the potential benefit for participants is a reduction in morbidity and mortality. The major potential risk of increasing target weight to achieve an ScvO2 of ≥65% is that of hypervolaemia. This risk can only be minimised by regular clinical assessment. The protocol requires clinician review of patients prior to any increase in target weight, which should protect against any potential harm. The protocol dictates that in the presence of clinical signs of fluid overload, no further increase in target weight will occur, and the clinician will reduce the target weight of the patient according to their assessment.

Where is the study run from?
Wessex Kidney Centre (UK)

When is the study starting and how long is it expected to run for?
May 2015 to November 2015

Who is funding the study?
Wessex Kidney Centre (UK)

Who is the main contact?
Dr Adam Kirk

Trial website

Contact information



Primary contact

Dr Adam Kirk


Contact details

Wessex Kidney Centre
Qa Hospital
Southwick Hill Rd
United Kingdom
+44 (0)7966 015047



Additional contact

Dr Nicholas Sangala


Contact details

Flat 2
5 Jerningham Road
SE14 5NH
United Kingdom

Additional identifiers

EudraCT number number

Protocol/serial number


Study information

Scientific title

Using central venous saturations >65% as an objective target for goal directed fluid management in haemodialysis patients using a tunneled venous catheter: a proof of concept trial



Study hypothesis

We hypothesise that In patients with a post dialysis ScvO2 less than 65%, an increase in target weight will result in a increase in ScvO2 to above 65% and that rise will correspond to an increase in cardiac output.

Ethics approval

Not provided at time of registration

Study design

Proof-of-concept single-arm interventional study

Primary study design


Secondary study design

Non randomised study

Trial setting


Trial type

Quality of life

Patient information sheet

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


Patients with end stage renal failure receiving maintenance haemodialysis though a tunneled internal jugular dialysis catheter


The intervention is an incremental increase in target weight by 0.5 kg per dialysis session.

Intervention type



Drug names

Primary outcome measure

Post dialysis ScvO2 measured by blood gas analysis

Secondary outcome measures

1. Cardiac output using the Cheetah NICOM both pre and post dialysis as described
2. Adverse events that may occur as a result of the study intervention
3. QOL questionnaire

Overall trial start date


Overall trial end date


Reason abandoned (if study stopped)

Lack of staff/facilities/resources


Participant inclusion criteria

1. Aged > 18 years old
2. Diagnosed with ESRD on maintenance haemodialysis via a central venous catheter
3. Haemoglobin >10mg/dL
4. Patient is able and willing to give informed consent

Participant type


Age group




Target number of participants


Participant exclusion criteria

1. There is planned and imminent movement of the patient to a satellite haemodialysis unit
2. Individuals requiring supplementary oxygen routinely
3. The presence of a functioning fistula
4. There is planned and imminent surgery for transplantation and/or fistula formation
5. Patient survival predicted to be <3months

Recruitment start date


Recruitment end date



Countries of recruitment

United Kingdom

Trial participating centre

Wessex Kidney Centre
Queen Alexandra Hospital Southwick Hill Road
United Kingdom

Sponsor information


Queen Alexandra Hospital

Sponsor details

Southwick Hill Road
United Kingdom

Sponsor type

Hospital/treatment centre



Funder type

Hospital/treatment centre

Funder name

Wessex Kidney Centre (UK)

Alternative name(s)

Funding Body Type

Funding Body Subtype


Results and Publications

Publication and dissemination plan

The outcome of this study will first be reported locally following which publication in a peer-reviewed journal will be sought. Each trial participant will receive a letter informing him or her about the trial results, following the trial’s conclusion.

Intention to publish date

Participant level data

Not provided at time of registration

Basic results (scientific)

Publication list

Publication citations

Additional files

Editorial Notes

29/01/2018: The trial did not start due to lack of funding.