Acid-base status, hypothermia and cardiac surgery

The optimal method of pH management during hypothermia is controversial. A review of current experimental and laboratory investigations comparing different pH schemes is presented. The biochemical and metabolic consequences of keeping pH constant (pH-stat) as compared to allowing the pH to increase with hypothermia (alpha-stat) are discussed. It is concluded that, on the basis of experimental and clinical studies, the alpha-stat pH management scheme may be preferable to that of keeping pH constant throughout a wide temperature range in humans.