Approach to Elevated Bicarbonate (HCO3)

Risk Factors for Hypercapnea? (Hx of COPD, OSA, sedative use, CNS/muscular disorders?)

(+) Evaluate for Respiratory Acidosis (Check Blood Gas)

(-) Likely Metabolic Alkalosis

Urine CI < 20 (Saline Responsive)

 • GI Hydrogen loss (Vomiting/NG)

 • Laxatives/Villous Adenoma

 • Remote Diuretics - Loop or Thiazides

 • Volume Contraction

Urine Cl > 20 (Saline Unresponsive):

 • Excess Mineralocorticoid

 • Primary Hyperaldosteronism

 • Recent Diuretics - Loop or Thiazides

 • Licorice

 • Liddle's. Barter, or Gitelman Syndrome



Unremarkable Labs @UnremarkableLab



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