Anion gap metabolic acidosis

From IDWiki

Definition

  • Metabolic acidosis with an increased anion gap

Differential Diagnosis

GOLDMARK

  • Glycols: ethylene (AKI, osmolar gap) and propylene (osmolar gap)
  • Oxoproline (acetaminophen)
  • L-lactic acidosis: rapid-onset
  • D-lactic acidosis: bowel stasis
  • Methanol: visual changes, osmolar gap
  • ASA
  • Renal failure
  • Ketoacidosis

Biochemical Approach

  • Lactic acidosis
    • Type A: impaired tissue oxygenation
      • Systemic hypoperfusion and shock
    • Type B
      • Metformin
      • Malignancy
      • Chronic alcohol intake (mild)
      • HIV medications
      • IV epinephrine
      • Mitochondrial dysfunction
      • Propofol
      • Linezolid
    • D-lactaic acidosis: short bowel syndrome
  • Ketoacidosis
    • Diabetic ketoacidosis (DKA)
    • Alcoholic ketoacidosis
    • Starvation
  • Toxins
    • Salicylates
    • Acetaminophen (5-oxoproline)
    • Methanol (formic acid)
    • Ethylene glycol (glycolic acid and oxalic acid)
  • Renal failure (acute or chronic)

Epidemiology

Risk Factors

Clinical Manifestations

  • Rapid onset: lactic acidosis
  • Osmolar gap: methanol, ethanol, ethylene glycol
  • Visual changes: methanol
  • AKI: ethylene glycol
  • Normal pH: ethanol
  • Slow bowel transit: D-lactic acidosis

Investigations

  • Serum electrolytes
    • Anion gap
    • Delta-delta: increase in anion gap should be matched by equal decrease in bicard
  • Serum osmolarity
  • Lactate, to rule out lactic acidosis

Management

  • Treat underlying cause