Metabolic acidosis.

Metabolic acidosis is the most frequent acid-base abnormality observed in the critically ill. Although there are many different causes, in the absence of ketosis and renal failure lactic acidosis is the most likely underlying disturbance. Controversy continues to surround the relative roles of the liver and the kidneys in the control of acid-base balance. There is no consensus concerning the use of bicarbonate in the treatment of a life-threatening metabolic acidosis.