Lactic acidosis. A new insight?

From an intensivist point of view, lactic acid is (i) responsible for metabolic acidosis, (ii) related to anoxia or ischemia and (iii) associated with poor prognosis. Conversely, from a biochemist point of view lactate is a good cellular substrate which can be easily converted to pyruvate and used as gluconeogenic substrate, or oxidised or transaminated into alanine. Hence the main question is not anymore to assess the value of lactate concentration as a marker of severity (it is well established) but rather to understand the metabolic meaning of its increase: is it beneficial or deleterious? In fact several recent experimental works have shown that instead of being a negative consequence, lactate production and related metabolic acidosis due to the stimulation of anaerobic ATP-production pathway could be a protective adapted response.