Metabolic Acidosis: Causes

Elevated anion gap:

• Methanol intoxication
• Uremia
• Diabetic ketoacidosis, alcoholic ketoacidosis, starvation ketoacidosis
• Paraldehyde toxicity
• Isoniazid
• Lactic acidosis
  • Type A:  tissue ischemia
  • Type B:  Altered cellular metabolism
• Ethanol or ethylene glycol intoxication
• Salicylate intoxication

Normal anion gap: will have increase in [Cl-]

• GI loss of HCO₃-
  • Diarrhea, ileostomy, proximal colostomy, ureteral diversion
• Renal loss of HCO₃-
  • proximal RTA
  • carbonic anhydrase inhibitor (acetazolamide)
• Renal tubular disease
  • ATN
  • Chronic renal disease
  • Distal RTA
  • Aldosterone inhibitors or absence
  • NaCl infusion, TPN, NH₄+ administration