Deep hypothermia is a usefull tool to improve technical results in cardiovascular surgery and is nowadays the major strategy used to reduce ischemic injury. Hypothermia reduces metabolism and preserves cellular stores of high-energy phosphates. The regulation of tissue pH during hypothermia is important for cellular homeostasis. Furthermore, hypothermia has important effects on pH by altering the dissociation constant of water and various metabolics intermediates and the question of optimal blood gas management during deliberate hypothermia has been subject of much controversy. Two approaches have been advocated for pH management during hypothermia, the first termed pH strategy, where blood pH is maintained constant at 7,40 at all temperatures with PaCO2 adjustment, and in the second type of regulation, termed α-stat strategy, the blood pH is increased according to decrease in temperature and the total CO2 , content of the blood remain constant. In this present review the relationship between blood pH and intracelular pH and the ionic alterations induced by hipothermia are discussed.
hipothermia, induced