Causes of Lactic acidosis are classically divided into 2 types by the Cohen & Woods classification based upon the presence or absence of an oxygen demand/delivery mismatch:

Type A: Oxygen Demand / Delivery Mismatch
(Anaerobic respiration as a result of tissue hypoxia)
  • Hypoperfusion (septic shock, cardiogenic shock, hypovolaemic/haemorrhagic shock, obstructive shock)
  • Hypoxaemia
  • Severe anaemia
  • Carbon monoxide poisoning
  • Seizures / convulsions
  • Shivering
  • Exercise
  • Hyperthermia
Type B: No Oxygen Demand / Delivery Mismatch
Type B1: Associated with underlying disease
  • Liver disease
  • Thiamine deficiency
  • Leukaemia
  • Lymphoma
  • AIDS
Type B2: Associated with drugs and toxins
  • Cyanide
  • Metformin
  • Beta-agonists
  • Methanol
  • Propofol (PRIS)
  • Nitroprusside infusion
  • Ethanol intoxication in chronic alcoholics
  • Anti-retroviral drugs
Type B3: Associated with inborn errors of metabolism
  • Congenital enzyme defects (e.g. pyruvate dehydrogenase deficiency)