Bicarbonate HD Study, V1.0
Research type
Research Study
Full title
Factors affecting bicarbonate levels in patients on haemodialysis
IRAS ID
366999
Contact name
Enric Vilar
Contact email
Sponsor organisation
East and North Hertfordshire NHS trust
Duration of Study in the UK
0 years, 6 months, 1 days
Research summary
Metabolic acidosis is defined as serum bicarbonate concentration <22mmol/l. According to the KDIGO 2022 guidelines, metabolic acidosis affects approximately 15% of all CKD patients, particularly in advanced CKD. Metabolic acidosis is a common yet under-explored problem in those on maintenance haemodialysis. With decline in glomerular filtration rate (GFR) the ability of kidneys to excrete hydrogen ions and generate bicarbonate decreases leading to chronic metabolic acidosis. Metabolic acidosis in CKD is contributed to by increased acid load from food and protein metabolism, loss of bicarbonate from the kidneys/gastrointestinal tract, and diminished net acid excretion by the kidneys. Persistent metabolic acidosis is associated with complications including muscle wasting, altered bone metabolism, risk of cardiovascular events and more rapid progression to kidney failure.
This study aims to systematically assess bicarbonate levels in dialysis patients and identify factors associated with suboptimal correction. By exploring both patient-level (e.g. diet and ethnic group) and system-level (dialysis prescription e.g. HDF volume) variables, this research will provide insight into the determinants of bicarbonate balance in real-world practice.
This will be a cross-sectional single center study recruiting 60-100 adult patients with end stage renal disease on dialysis. Participants will have 2 study visits, during their routine dialysis session. During the study visits the participants will have recording of demographic and clinical data, measurement of bicarbonate levels at 3 timepoints (pre/post dialysis session 1, pre session 2), foods and drinks consumed over 1-2 days (30 patients subset only). Standard-of-care collected dialysis data and blood result data will also be recorded.
Improved understanding of these factors could inform novel methods of individualising the bicarbonate prescription of the patient according to patient factors and the dialysis/HDF prescription. We hope that this study would provide preliminary data that would inform a potential future intervention study.
REC name
HSC REC A
REC reference
26/NI/0019
Date of REC Opinion
10 Feb 2026
REC opinion
Further Information Favourable Opinion