**3.3 Summary**

Hyperlactatemia may be physiologic or pathologic. It can be caused by increased lactate production (i.e., an increase in the rate of glycolysis or unregulated substrate entry into glycolysis) as well as a decrease in its clearance (i.e., liver or renal insufficiency).

Common causes for type A hyperlactatemia include intense exercise or hypoxemia, anemia, systemic or regional hypoperfusion, shock, CO poisoning and impaired liver blood flow below 25%. This type is more common in postoperative patients.
