Pyruvate is the normal end-product of glycolysis (glucose metabolism). In the presence of oxygen, pyruvate is converted to acetyl-coenzyme A (CoA), which ultimately produces energy in the form of ATP. However, in an oxygen-deficient environment, CoA is not produced and pyruvate is converted to lactate through anaerobic metabolism. The quantitative measurement of lactic acid in plasma indicates the severity of oxygen deprivation.
An elevated lactate is known to be associated with increased mortality rates. If the lactate can be cleared, prognosis improves.
Patients who develop severe sepsis or septic shock commonly demonstrate hyperlactemia and lactic acidosis. Increased lactate production during anaerobic metabolism and decreased lactate clearance are likely contributors to hyperlactemia.