Metabolic Acidosis in Patients with CKD and Hyperkalemia

Patients with chronic kidney disease may develop both metabolic acidosis and hyperkalemia. According to Erin E. Cook, ScD,  and colleagues, the prevalence of metabolic acidosis among patients with CKD and hyperkalemia is not well documented. Using medical record data from the Research Action for Health Network, the researchers estimated that prevalence. Results were reported online in Advances in Therapy [doi.org/10.1007/s12325-021-01886-5].

The study population included adult patients with CKD stage 3 to 5, and one or more outpatient potassium value >5.0 mEq/L, and one or more outpatient bicarbonate value available. Exclusion criteria included end-stage kidney disease in the prior year.

Two definitions of hyperkalemia (potassium >5.0 mEq/L and >5.5 mEq/L) and two definitions of metabolic acidosis (bicarbonate <19 mEq/L and <22 mEq/L) were used to estimate the prevalence of metabolic acidosis in each calendar year from 2014 to 2017 in patients with CKD and hyperkalemia.

In the 2017 patient cohort and among patients with CKD and hyperkalemia, those with metabolic acidosis were younger (69 vs 74 years), more likely to have advanced CKD (35% vs 13%), and more likely to use oral sodium bicarbonate (21% vs 4%) compared with patients without metabolic acidosis.

When hyperkalemia was defined as potassium >5.0 mEq/L, the prevalence of metabolic acidosis (<22 mEq/L) ranged from 25% to 29%. When hyperkalemia was defined as potassium >5.5 mEq/L, the prevalence of metabolic acidosis ranged from 33% to 39%.

In conclusion, the authors said, “Results demonstrated that prevalence estimates of metabolic acidosis varied based on the definition of hyperkalemia and metabolic acidosis used.”