Metabolic acidosis is where the body produces excessive quantities of acid, and when the kidneys aren't forming enough of the base, bicarbonate HCO3-, to remove acid from the body. If unchecked, it causes acidemia (i.e. blood pH<7.35).

Based upon anion gap, which is calculated by (Na+K)-(Cl+bicarbonate). Normally this concentration is about 8-16 mmol/L. An elevated anioin gap (>16) can indicate particular types of metabolic acidosis, particularly certain poisons, lactate acidosis, and ketoacidosis.

• Increased anion gap, which can be memorized with the mnemonic MUDPILES:
  • Methanol
  • Uremia (chronic kidney failure)
  • Diabetic ketoacidosis
  • Propylene glycol
  • Infection, iron, isoniazid, inborn errors of metabolism
  • Lactic acidosis
  • Ethylene glycol
  • Salicylates
• Normal anion gap, including:
  • Longstanding diarrhea (bicarbonate loss)
  • Bicarbonate loss due to taking topiramate
  • Pancreatic fistula
  • Uretero-sigmoidostomy
  • Renal tubular acidosis
  • Intoxication, w/ ammonium chloride, acetazolamide, bile acid sequestrants, isopropyl alcohol
  • Renal failure, occasionally
  • Inhalant abuse
  • Toluene

• Coma
• Death

• ABG
• Metabolic alkalosis
• Respiratory acidosis