I am combining the recommendations and practice points for sodium and metabolic acidosis in today’s post, because there is some overlap here.
What are the recommendations for sodium?
Up first, sodium recommendations. The recommendation is:
Recommendation 3.3.2.1: We suggest that sodium intake be <2g of sodium per day
Does it apply for everyone with CKD?
The working group suggested that this recommendation may not apply for those with:
- Salt-wasting CKD
- Malnutrition
- Exposure to extremely hot climates
Are there any good practice tools available to help with low sodium diet teaching?
I know I have mentioned this tool before, but I will again pump the project big life sodium calculator as an excellent tool to help individualize this recommendation.
Many patients have told me they don’t add salt to their food and therefore their sodium intake is low. So helping them figure out where their sodium is coming from and how much they are likely having can be a powerful teaching tool.
What are the recommendations for metabolic acidosis?
Practice Point 3.10.1: In people with CKD, consider use of pharmacological treatment with or without dietary intervention to prevent development of acidosis with potential clinical implications (e.g. serum bicarbonate <18mmol/L in adults).
Practice Point 3.10.2: Monitor treatment for metabolic acidosis to ensure it does not result in serum bicarbonate concentrations exceeding the upper limit of normal and does not adversely affect BP control, serum potassium or fluid status.
Why should we wait for a CO2 of 18mmol/L before treating?
The KDIGO group cite a 2021 systematic review for this recommendation. They highlight this review failed to demonstrate clear benefit for sodium bicarbonate vs placebo and risk of kidney failure. Furthermore, trials have reported that those taking sodium bicarbonate had higher costs and lower quality of life scores.
KDIGO also brings up the potential for sodium bicarbonate to increase blood pressure.
The KDIGO group recommends starting treatment at 18 to prevent more severe metabolic acidosis.
This will be something for me to discuss with my team. Currently, our clinic standards is any value outside of range, which in our labs is 19 and lower.
What do the guidelines say about diet for treating metabolic acidosis?
There is one small paragraph about dietary interventions for metabolic acidosis. It simply states that limiting consumption of acid-rich foods and/or increasing consumption of alkaline-rich foods can reduce acid production. Therefore diet is considered an additional strategy to control metabolic acidosis.
What do sodium restriction and metabolic acidosis have in common?
The primary treatment for metabolic acidosis is sodium bicarbonate. Not surprisingly sodium bicarbonate contains sodium.
In fact a 650mg tablet of sodium carbonate contains 177mg of sodium and 470mg of bicarbonate. So, someone needing 1000mg twice daily (as an example of a dose I see frequently in clinical practice) would be getting 544mg of sodium from their medication. This accounts for 27% of their total recommended sodium intake! That’s a lot.
So I think it’s good that KDIGO is promoting high doses of sodium bicarbonate but I think it is disappointing that diet isn’t taking a larger role in these recommendations.
