Effect of moderate hypothermia on serum level of neuron-specific proteins, oxygen delivery, acid-base balance of cerebral tissue and neurocognitive status in patients that underwent myocardial revascularization surgery

73 patients (mean age 52,3±0,9 years) with coronary heart disease, operated under bypass. The main group was formed of 30 patients operated under hypothermic bypass (t °С = 31,5±0,4 °С); the control group was formed of 43 patients operated under normothermic bypass (t °С = 36,0±0,5 °С). The parameters studied were: serum level of neuron-specific enolase and S-100beta protein; oxygen delivery and acid-base balance of cerebral tissue before, during and after the surgery; and neurocognitive status. The study shows that the use of hypothermic bypass entails more brain damage than the use of normothermic bypass, due to the activation of metabolic processes and generation of an oxygen deficit after hypothermic bypass. In our opinion, this fact accounts for the greater cognitive impairment in patiens operated under hypothermic bypass.