The accuracy of jugular bulb venous monitoring in detecting cerebral ischemia in awake patients undergoing carotid endarterectomy.

To investigate the accuracy of jugular bulb venous monitoring in detecting cerebral ischemia, we performed ipsilateral jugular bulb venous monitoring in 48 patients undergoing carotid surgery under regional anesthesia. Cerebral ischemia was assumed when neurologic deterioration occurred. During carotid clamping, the maximal arterial-jugular venous oxygen content difference [AJDO2 (max)], the minimal jugular venous oxygen saturation [SjO2 (min)], the maximal arterial-jugular venous lactate content difference [AJDL (max)], the maximal lactate oxygen index [LOI (max)], and the maximal modified LOI [mLOI (max)] were determined. To quantify the selectivity of each parameter, we performed receiver operating characteristic analysis and determined the area under the curve. The cutoff points providing the highest accuracy and the corresponding sensitivity (Se) and specificity (Spec) were determined. Neurologic deterioration occurred in 12 patients. All parameters, except AJDO2 (max), showed significant ability to distinguish between ischemic and nonischemic patients. The area under the curve for AJDL (max) was 0.840, for SjO2 (min) 0.766, for LOI 0.745, for mLOI 0.748, and for AJDO2 (max) 0.672. We found cutoff points of > or =0.16 mmol/L for AJDL (max) (Se=67%; Spec=86%) and < or =55% for SjO2 (Se=75%; Spec=83%). In conclusion, the present investigation shows that AJDL, SjO2, LOI, and mLOI provide the ability to detect cerebral hypoperfusion. The highest accuracy was found for AJDL. Neither the calculation of LOI nor of mLOI showed improved results.