A study of cognitive dysfunction in patients having carotid endarterectomy performed with regional anesthesia.

Carotid endarterectomy (CEA) reduces the risk of future stroke in patients with high-grade stenosis.1–5 Although the incidence of new neurologic findings associated with CEA is between 3% and 5%,5 approximately 25% of CEA patients having general anesthesia (CEA general) develop significant postoperative neurocognitive dysfunction based on performance on a battery of neuropsychometric tests administered before and after surgery when examined 1 day and 1 mo after surgery.6,7 We chose to define “significant” dysfunction as cognitive performance that is two standard deviations (SD) worse than performance in an appropriate control group. Although the mechanism of postoperative neurocognitive dysfunction is poorly understood, it is believed to be ischemic in nature, likely due to hypoperfusion during carotid artery cross-clamping. However, general anesthesia itself may contribute significantly to cognitive dysfunction.8–11 We hypothesized that patients scheduled for elective CEA with regional anesthesia (CEA regional) would develop short-term cognitive dysfunction at 1 day after surgery compared with a control group of patients if cognitive dysfunction was due to surgery. Cognitive performance in patients having CEA regional was compared with performance in a control group having coronary artery angiography and/or stenting (control) to account for the “practice effect” associated with repeated testing, and for the effect of mild sedation.