Metabolic acidosis is one of the earliest complications of chronic kidney disease (CKD), with a direct correlation between the decline in glomerular filtration rate (GFR) and reduction in serum BC¹.

Epidemiologic studies in patients with CKD have reported an independent association between serum BC (<22 meq/L considered low) and adverse renal outcomes and mortality¹. Limited data from small interventional trials of alkali therapy supplementation and dietary interventions (eg, increased fruit and vegetable intake) have shown the benefits of raising serum BC. Specifically, 1 study involving patients with CKD stages 4 and 5 and another involving CKD stage 2 hypertensive nephropathy reported slower decline in creatinine clearance/eGFR in patients receiving BC replacement^2,3.  

Less is known on the potential benefit of BC replacement in patients with acute kidney injury (AKI) with a recent Cochrane review finding no randomized controlled trials⁴ and national guidelines not recommending either in favor or against its use AKI⁵. Of note, BC therapy has also been associated with sodium and fluid overload, an increase in lactate and PCO2, and a decrease in serum ionized calcium⁶.

References

1. Dobre M, Rahman M, Hostetter TH. Current status of bicarbonate in CKD. J Am Soc Nephrol 2015;26:515-523.
2. de Brito-Ashurst I, Varagunam M, Raftery MJ, et al. Bicarbonate supplementation slows progression of CKD and improves nutritional status. J Am Soc Nephrol 2009; 20: 2075–2084.
3. Mahajan A, Simoni J, Sheather SJ, et al. Daily oral sodium bicarbonate preserves glomerular filtration rate by slowing its decline in early hypertensive nephropathy. Kidney Int 2010;78: 303–309.
4. Hewitt J, Uniacke M, Hansi NK, et al. Sodium bicarbonate supplements for treating acute kidney injury. Cochrane Database of Systematic Reviews 2012; Jun 13; (6):CD009204. doi: 10.1002/14651858.
5. Palevsky PM, Liu KD, Brophy PD, et al. KDOQI US commentary on the 2012 KDIGO clinical practice guideline for acute kidney injury. Am J Kidney Dis 2013;61:649-72.
6. Sabatini S, Kurtzman NA. Bicarbonate therapy in severe metabolic acidosis. J Am Soc Nephrol 2009;20:692-695.

Contributed in part by Cynthia Cooper, MD, Mass General Hospital, Boston, MA.