Prevalence of Metabolic Acidosis Among Patients with Chronic Kidney Disease and Hyperkalemia

Abstract

Although hyperkalemia and metabolic acidosis often co-occur in patients with chronic kidney disease (CKD), the prevalence of metabolic acidosis among patients with CKD and hyperkalemia is understudied. Therefore, we used medical record data from the Research Action for Health Network to estimate this prevalence. Adult patients with CKD stage 3–5,\u2009≥\u20091 outpatient potassium value\u2009>\u20095.0 mEq/l, and\u2009≥\u20091 outpatient bicarbonate value available were identified. Patients with end stage kidney disease (ESKD) in the prior year were excluded. The prevalence of metabolic acidosis in each calendar year from 2014 to 2017 among patients with CKD and hyperkalemia was estimated using two definitions of hyperkalemia (potassium\u2009>\u20095.0 mEq/l and\u2009>\u20095.5 mEq/l) and metabolic acidosis (bicarbonate\u2009<\u200918 mEq/l and\u2009<\u200922 mEq/l). In the 2017 patient cohort and among patients with CKD and hyperkalemia, patients with metabolic acidosis were younger (69 versus 74 years), more likely to have advanced CKD (35% versus 13%), and use oral sodium bicarbonate (21% versus 4%) than patients without metabolic acidosis. The prevalence of metabolic acidosis (<\u200922 mEq/l) ranged from 25 to 29% when hyperkalemia was defined by potassium\u2009>\u20095.0 mEq/l and ranged from 33 to 39% when hyperkalemia was defined by potassium\u2009>\u20095.5 mEq/l. Results demonstrated that prevalence estimates of metabolic acidosis varied based on the definition of hyperkalemia and metabolic acidosis utilized.