The purpose of this study is to characterise in detail cardiac, cerebral and renal structure, function and perfusion in patients on haemodialysis (HD) using magnetic imaging techniques. The effects of a standard prescription haemodialysis (dialysate temperature 37 C) will be compared to a thermocontrolled (or isothermic) haemodialysis prescription to ascertain if thermocontrolled HD provides a protective effect on organ perfusion and circulatory stress when compared to conventional haemodialysis. The BTM (blood temperature monitor, Fresenius) offers a way to overcome this to regulate thermal balance during dialysis and achieve a neutral thermal balance (isothermic) over the dialysis session. Other dialysis parameters will be standardised between treatment arms using blood volume monitoring (BVM) and clinical assessments.

The purpose of this study is to characterise in detail cardiac, cerebral and renal structure, function and perfusion in patients on haemodialysis (HD) using magnetic imaging techniques. The Primary objectives are to investigate the difference in cardiac perfusion, structure and function between standard HD and thermocontrolled HD using magnetic imaging techniques, to observe the the changes in renal perfusion and oxygenation within one dialysis session and the changes to cerebral perfusion within one dialysis session.

The secondary objectives are to investigate the difference in cerebral perfusion, structure, oedema and function between standard HD and thermocontrolled HD, the difference in renal perfusion and oxygenation between standard HD and thermocontrolled HD and the differences in visual acuity and cognitive assessment across a dialysis session and over a dialysis treatment course.

Exclusion Criteria:

• Change in dry weight (clinically defined) in 4 weeks prior to recruitment

• Dialysate composition other than: sodium≥137mmol/L, potassium≥2.0mmol/L, calcium≥1.5mmol/L, magnesium≥0.5mmol/L, glucose 1.0g/L

• Instability on dialysis in 4 weeks prior to recruitment leading to either:

  • Emergency medical attention
  • Infusion of additional fluid
  • Loss in consciousness
  • Arrhythmia
  • Chest pain
  • Or any other medical condition that precludes the scan session in opinion of the investigator

• Dialysed via a synthetic line, central venous catheter or graft

• Qa < 500ml/min

• NYHA Stage IV heart failure (New York Heart Association)

• Active infection or malignancy

• Contraindication to MRI scanning including claustrophobia, pacemaker, metallic implants etc

• Pregnancy (pregnancy test will be conducted with female patients aged ≤ 55 years) or planning pregnancy or lactation period

• Medical conditions or overall physical frailty precludes scan session in opinion of investigator

• Unable or unwilling to provide informed consent

• Any condition which could interfere with the patient's ability to comply with the study

• Participation in an interventional clinical study during the preceding 30 days

Inclusion Criteria:

• Age 18-80, male and female
• Informed consent signed and dated by study patient and investigator/authorised physician
• Average (4 weeks prior to recruitment) Ultrafiltration volumes ≥ 0.5 litres/ dialysis session
• Receiving dialysis via an arteriovenous fistula
• Must be able to follow simple instruction in English (on safety grounds for MRI scans) and be able to understand the nature and requirements of the study
• Stable dialysis prescription
• CKD5 (Chronic kidney disease) patients having renal replacement therapy with haemodialysis/ haemodiafiltration (>90 days)