Alpha-stat vs. pH-stat strategy during hypothermic cardiopulmonary bypass.
There are two different strategies of acid-base regulation during hypothermis. The alpha-stat strategy of ectotherms maintains the temperature-uncorrected arterial PCO2 and pH at normothermic values (i.e., 40 mmHg and 7.4, respectively), irrespective of the body temperature. In contrast, the pH-stat of hibernators maintains the temperature-corrected pH and PCO2 at the normal values at the different body temperatures. Clinically, it appears that it is more physiological to use the alpha-stat strategy whenever tepid or moderate hypothermic CPB is used in order to maintain intracellular electrochemical neutrality, and to adopt the pH-stat strategy whenever deep hypothermic circulatory arrest is induced, in order to otimize brain protection.
Baraka
Anis
A
Department of Anesthesiology, American University of Beirut, P.O. Box 11-0236, Beirut 1107 2020, Lebanon.
D000137:Acid-Base Imbalance / Q000209:etiology / Q000628:therapy*; D000328:Adult; D002245:Carbon Dioxide / Q000008:administration & dosage; D002315:Cardiopulmonary Bypass; D002648:Child; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007036:Hypothermia, Induced / Q000009:adverse effects*; D010100:Oxygen / Q000008:administration & dosage
D002245:Carbon Dioxide; D010100:Oxygen