From the Guidelines
The KDIGO guidelines recommend oral bicarbonate supplementation for patients with CKD and serum bicarbonate concentrations <22 mmol/l to maintain serum bicarbonate within the normal range, unless contraindicated 1.
Key Recommendations
- The goal of sodium bicarbonate (NaHCO3) therapy is to maintain serum bicarbonate levels within the normal range, which is essential for slowing CKD progression, reducing bone resorption, improving nutritional status, and decreasing muscle wasting.
- The typical starting dose is not specified in the KDIGO guidelines, but it is generally recommended to start with a low dose and titrate based on regular monitoring of serum bicarbonate levels.
- Potential side effects of NaHCO3 therapy include sodium retention, fluid overload, and worsening hypertension, so careful monitoring is essential, particularly in patients with heart failure or uncontrolled hypertension.
Patient Selection
- Patients with CKD and serum bicarbonate concentrations <22 mmol/l are eligible for oral bicarbonate supplementation.
- Patients with severe acidosis (bicarbonate <12 mEq/L) may require intravenous sodium bicarbonate, especially if there are signs of hemodynamic instability or severe symptoms.
Monitoring and Titration
- Regular monitoring of serum bicarbonate levels is essential to titrate the dose of NaHCO3 and minimize the risk of side effects.
- Patients should be monitored for signs of sodium retention, fluid overload, and worsening hypertension, and the dose of NaHCO3 should be adjusted accordingly.
Alternative Therapies
- Potassium citrate may be considered as an alternative to NaHCO3 in patients who cannot tolerate the sodium load, although this is not specified in the KDIGO guidelines 1.
From the Research
KDIGO Guidelines for NaHCO3 Therapy
- The KDIGO (Kidney Disease: Improving Global Outcomes) recommendations support oral sodium bicarbonate supplementation and maintaining HCO3- concentration ≥22 mmol/l in all CKD patients 2.
- The guidelines aim to treat metabolic acidosis, which can have substantial adverse effects such as impairing albumin biosynthesis and glucose metabolism, increasing protein catabolism, and increasing bone resorption 2.
Rationale for NaHCO3 Therapy
- Metabolic acidosis is frequently associated with chronic kidney disease (CKD) progression, and treating it with sodium bicarbonate may improve kidney and patient survival 3.
- Sodium bicarbonate therapy may halt worsening kidney function by correcting serum bicarbonate levels and treating metabolic acidosis, although it may not significantly improve the estimated glomerular filtration rate (eGFR) 4.
Safety and Efficacy of NaHCO3 Therapy
- Sodium bicarbonate therapy has been shown to be safe and effective in treating metabolic acidosis in CKD patients, with a favorable safety profile 4.
- However, some studies have raised concerns about the potential risks of sodium bicarbonate loading, including increased arterial pressure and kidney damage in rats with CKD 5.
- A systematic review and meta-analysis found that sodium bicarbonate significantly increased serum bicarbonate in CKD patients, but had a non-significant increase in eGFR, and no significant association with adverse outcomes such as death, prolonged hospitalization, or gastrointestinal disorders 4.