Correlation of Cerebral Oximetry With Internal Carotid Artery Stump Pressures in Carotid Endarterectomy

Abstract

Objective: This study compares internal carotid artery (ICA) mean stump pressures (SPs) with cerebral oximetry monitoring during carotid endarterectomy (CEA). Methods: A total of 104 consecutive patients undergoing CEA under general anesthesia (GA) during a 10-month period were prospectively evaluated. Baseline and postcarotid clamp regional cerebral oxygen saturation (rSO2) and mean ICA SPs were measured. Demographic, surgical, and medical variables were recorded for each case. Results: There were no postoperative strokes. Thirteen patients were excluded because of incomplete data. Of the 40 patients who had <10% drop in rSO2, 6 had SP <40 mm Hg. Regional cerebral oxygen saturation with a 15% saturation drop threshold was 76.3% sensitive and 81.1% specific in detecting patients with SP <40 mm Hg. With a threshold of 20% drop, sensitivity and specificity were 57.9% and 86.8%, respectively. Conclusions: Relative drop in rSO 2 is neither sensitive nor specific in detecting patients with mean SP <40 mm Hg. These data do not support the use of cerebral oximetry as the sole monitoring modality during carotid endarterectomy under GA.