The effect of cerebral desaturation on patient's cognitive functions in carotid endarterectomy surgery

Carotid endarterectomy (CEA) is an estabilished surgery procedure in patients withhigh-grade carotid artery stenosis. Cerebral hypoperfusion after clamping internal carotidartery can cause the development of a new stroke or can aggravate existing damage. Near-infrared (NIRS) spectroscopy provides monitoring continously and non-invasively cerebraloxigenation, in critical patients, early detection of cerecerebral iscemia due to cerebralhypoperfusion and to reduce the early complications. Postoperative cognitive dysfunction(POCD) is a change of cognitive functions following by the surgery and anesthesia. And thesechanges can occure after the carotid endarectomy operations. Mini mental status examination(MMSE) which is one of the neuropsycometric test is commonly used for assesment ofPOCD. In this prospective and observational study, our goal is to evaluate the cerebraldesaturation by using NIRS whether it causes POCD or not.We enrolled 48 patients ongoing carotid endarterectomy under general anesthesia.Haemodinamic and NIRS assesments of the patients were recorded; such as their basal beforethe operation (T1), post-intubation (T2), pre-clamping (T3), post-clamping 5 minutes (T4),post-clamping 10 minutes (T5), clamping off 5 minutes (T6), pre-extubation (T7), post-extubation (T8). We used MMSE to patients preoperative day 1 and postoperative day 2.Cerebral desaturation was seen on %33 percent of patients. After clamping internalcarotid artery, regional cerebral oxigen saturation (rSO2) was decrased slightly in the earlystage. During the clamping time rSO2 values increased and at the end of the operation itreached to previous values and even higher than the basal. We could not detect POCD afterthe postoperative early period.In conclusion, NIRS is a practical and efficient way to indicate the cerebralhypoperfusion. As a result of our study, it is not possible to corrolate the NIRS values withPOCD. We suggest the intraoperative usage of NIRS to provide serebral hypoperfusionawareness