Causes of Non-Gap Metabolic Acidosis - Differential Diagnosis Algorithm

Normal Anion Gap (<14) (Loss of Bicarbonate) - Need to correct anion gap for albumin: For every drop of 10 for albumin (from 40) add 2.5 to the anion gap

GI Tract Loss (Negative urine net charge)

 • Diarrhea

 • Fistula

Renal Loss - Direct Loss Negative U net charge High FE-HCO3

 • RTA Type II

 • Carbonic anhydrase inhibitor

Principal Cell Problem - Low TTKG

 • RTA Type IV

Alpha-Intercalated Cell Problem - High TTKG

 • RTA Type I



#MetabolicAcidosis #NonGap #Nephrology #Differential #Diagnosis #Algorithm #Causes