Acid-Base Management in Chronic Kidney Disease

Chronic kidney disease impairs the kidneys’ ability to excrete acid and regenerate bicarbonate, leading to a state of metabolic acidosis that accelerates nephron loss, promotes protein catabolism, worsens bone demineralisation and increases cardiovascular risk. Early stages of chronic kidney disease often feature subtle reductions in serum bicarbonate, while advanced stages and dialysis dependence bring pronounced acid‐base disturbances. Management strategies aim to restore acid‐base homeostasis without inducing alkalosis or electrolyte imbalance. Oral bicarbonate supplementation, dietary interventions and tailored dialysate prescriptions constitute the cornerstone of therapy. Maintaining serum bicarbonate above a threshold of approximately 22 mmol/L has been associated with slower progression of renal decline, improved nutritional status and reduced hospitalisation. In dialysis patients, dialysate bicarbonate concentration must balance correction of pre‐dialysis acidosis against post‐dialysis alkalosis and its haemodynamic sequelae. Preservation of residual renal function further contributes to acid excretion and may modulate intradialytic requirements. Current research focuses on personalised approaches that integrate patient‐specific factors such as residual renal function, comorbidities and nutritional status, with the overarching goal of mitigating the systemic consequences of chronic metabolic acidosis.

Research from Nature Portfolio

Recent clinical trials have compared time-dependent versus constant dialysate bicarbonate profiles during haemodialysis. In a crossover study of twenty patients undergoing four-hour sessions, alternating the dialysate concentration mid-treatment altered the trajectory of blood bicarbonate and pH change, demonstrating that a timed shift from 35 mmol/L to 30 mmol/L (or vice versa) can fine-tune acid-base correction without affecting the clearance of uraemic solutes. These findings support the feasibility of dynamic dialysate prescriptions to optimise acid-base balance during treatment.

Acid-Base Management in Chronic Kidney Disease publication trend

The graph below shows the total number of articles in acid-base management in chronic kidney disease across all publications each year (not limited to Nature Index journals).

Technical terms

Metabolic acidosis: a clinical state characterised by low blood pH and bicarbonate levels due to impaired renal acid excretion.

Dialysate bicarbonate concentration: the prescribed level of bicarbonate in dialysis fluid used to correct acid-base disturbances during haemodialysis.

Inter-dialytic period: the interval between successive haemodialysis sessions during which acids and uraemic toxins accumulate.

Residual renal function: the remaining operative filtration capacity of the native kidneys in dialysis patients, contributing to acid-base and fluid balance.

References

1. Effect of time-dependent dialysate bicarbonate concentrations on acid–base and uremic solute kinetics during hemodialysis treatments. Scientific Reports (2024).
2. Oral sodium bicarbonate in people on haemodialysis: a randomised controlled trial. BMC Nephrology (2021).
3. Acid–base balance in hemodialysis patients in everyday practice. Renal Failure (2022).
4. Hemodynamic effects of low versus high dialysate bicarbonate concentration in hemodialysis patients. Hemodialysis International (2024).
5. Metabolic acidosis in hemodialysis patients: a review. Brazilian Journal of Nephrology (2017).