[Changes in indicators of brain metabolism in heart surgery patients under normal and hypothermic perfusion]

Metabolism of the brain was studied in 82 cardiosurgical patients operated on under conditions of hypothermal and normothermal artificial circulation (AC). The principal differences in the pattern of changes of cerebral metabolism were observed at the stage of heart connection to the bloodflow, corresponding to the period of warming during hypothermal AC. The detected reduction of oxygen extraction and arteriovenous glucose difference in the normothermal group may be a result of cerebral bloodflow shunting, and more pronounced stimulation of free-radical processes be indicative of the possible injury to cerebral structures in the absence of protective effect of hypothermia.