• characterised by an elevated arterial blood lactate level and an increased anion gap ([Na + K] - [Cl + HCO₃]) of > 20 mmol.
• It can be a consequence of overproduction and/or reduced metabolism of lactic acid.
• The main sites of lactate metabolism are the liver and kidney

There are two recognised types of lactic acidosis:

1. Type A is due to

• Tissue hypoxia
• Inadequate tissue perfusion and
• Anaerobic glycolysis

which may be seen in cardiac arrest, shock, hypoxaemia and anaemia.

Management involves reversing the underlying cause of tissue hypoxia.

2. Type B occurs in the absence of tissue hypoxia.

The causes include:

• Hepatic failure
• Renal failure
• Diabetes mellitus
• Pancreatitis
• Infection and
• Drugs (aspirin, ethanol, methanol, biguanides and intravenous fructose).

Optimising tissue oxygen delivery, correcting the cause and infusions of intravenous sodium bicarbonate form the mainstay of treatment.

Peritoneal dialysis has been used in resistant cases.