Etiologies of Non-AG Metabolic Acidosis
GI losses of HCO3
Diarrhea, intestinal or pancreatic fistulas or drainage
RTAs
Early renal failure
- Impaired generation of ammonia
Ingestions
- Acetazolamide, sevelamer, cholestyramine, toluene
Dilutional
- Due to rapid infusion of bicarbonate-free IV fluids
Posthypocapnia
- Respiratory alkalosis → renal wasting of HCO3; rapid correction of resp. alk. → transient acidosis until HCO3 regenerated
Ureteral diversion
- Colonic Cl–/HCO3– exchange, ammonium reabsorption