[Cerebral metabolism in carotid endarterectomy (oxygenation, electrolytic balance, glucose consumption)]

The purpose of this study was to evaluate regional oxygenation, glucose metabolism and electrolytic balance of the brain in patients with an atherosclerotic lesion of the carotid arteries in the perioperative period. A total of 42 patients presenting with various combinations and degree of manifestation of occlusive-and-stenotic damages to the brachiocephalic arteries were examined. Regional oxygenation of the brain (rS02) was assessed using the unit INVOS 3100 (Somanetics Corp., USA) at rest, with the patient lying upon the back and breathing atmospheric air and oxygen, and while changing the assumed body position. The acid-base state, gases, electrolytic composition and the level of glucose in the arterial blood and blood outflowing from the brain were analysed with the help of the unit STAT profile 5 Analyzer (NOVA Biomedical, USA). Four variants of perioperative alterations in oxygenation of the brain were determined, with the respective comparative characteristics thereof given. The authors have shown that the rS02 at rest prior to surgery was determined in unilateral stenosis of the internal carotid artery on the side of the lesion, while in bilateral stenosis - on the side of the greater lesion of the internal carotid artery. A decrease in the rS02 value in patients with the internal carotid artery narrowed by 70% and more during the orthostatic test is characteristic of subcompensation of the cerebral blood flow. Decompensation thereof manifests itself by a positive reaction of rS02 to oxygen inhalation. Patients with the initially low values of rS02 during reperfusion of the brain were found to have diminished glucose utilization, while in the normal rS02, glucose metabolism was noted to increase.