Metabolic acidosis differentials

Normal anion gap metab acidosis

When concentration of Cl ↑ to replace HCO3

ABCD

  • Addison's/Adrenal insufficiency
  • Bicarb loss - GI or renal
    • diarrhoea, vomiting, ileostomy
  • Chloride excess
  • Diuretics (acetazolamide)

HARDUPS

  • H: H+ secretion failure → renal tubular acidosis
  • A: acetazolamide; Addison's
  • R: renal tubular acidosis type 2
  • D: diarrhoea - GI loss of HCO3
  • U: uretopelvic fistula
  • P: post-hypocapnia
  • S: spironolactone

High anion gap metab acidosis HAGMA

When concentration of an unmeasured anion increases to replace HCO3 or impaired H excretion
often ↑ acid

MUDPILERS

  • M: Methanol
  • U: uraemia
  • D: Diabetic ketoacidosis
  • P: paracetamol, propylene glycol, paraldehyde
  • I: infection, iron, isoniazid, inborn errors of metabolism (pyroglytamic acidosis)
  • L: lactic acidosis (shock, hypoxia, drugs)
  • E: ethylene glycol, ethanol
  • R: rhabdomyolysis
  • S: salicylate
  • Carbon monoxide, cyanide
  • alcoholic/starvation ketoacidosis

Or see:

G glycols (ethylene glycol & propylene glycol)
O oxoproline, a metabolite of paracetamol
L L-lactate, the chemical responsible for lactic acidosis
D D-lactate
M methanol
A aspirin
R renal failure
K ketoacidosis, ketones generated from starvation, alcohol, and diabetic ketoacidosis