Time to Post-Anesthesia Neurological Evaluation and Hemodynamic Stability in Carotid Endarterectomy Comparing Three General Anesthetic Techniques Targeted to a Preset Bispectral Index Value: A Pilot Study

Carotid endarterectomy (CEA) has a 1-5% risk of periprocedural stroke. The ability to emerge patients from anesthesia quickly to detect neurological abnormalities immediately after surgery is vital in this patient population. The objective of this pilot study was to assess if any of three general anesthetic techniques for CEA are associated with a shorter time to a reliable postoperative neurological exam. Secondary objectives were to assess postoperative cognitive dysfunction (POCD), postoperative delirium (POD), and hemodynamic stability. Twenty-one patients undergoing CEA were enrolled and randomized to different combinations of inhalational and intravenous anesthesia: Group A: propofol, remifentanil, and desflurane; Group B: dexmedetomidine, remifentanil, and desflurane; Group C: remifentanil and desflurane. Anesthetic depth was titrated using a bispectral index (BIS) monitor to a goal of 50-60. Time was recorded from surgery end to first meaningful neurological exam. Neurocognitive testing was completed preoperatively and up to 1 week postoperatively to assess POD (3D-CAM) and POCD (Short Blessed Test). Time to first reliable neurological exam was 2 minutes longer in group A (9 min ± 4 min) compared to group B and group C (7 min ± 3 min; 7 min ± 4 min), although this was not statistically significant. In addition, extubation time was significantly longer in group A (11 min) compared to group B and group C (5 min; 6 min) (P = 0.03). 3D -CAM and Short Blessed Test data along with hemodynamics did not differ significantly between the groups. Time to first useful neurologic exam and hemodynamics did not differ between the groups. However, extubation time was significantly prolonged in patients who received propofol, but not dexmedetomidine, as part of their anesthetic for CEA. These findings are best verified in an adequately powered prospective randomized study.