title: Dexmedetomidine does not increase the incidence of intracarotid shunting in patients undergoing awake carotid endarterectomy.
abstract: Systemic administration of dexmedetomidine (DEX) decreases cerebral bloodflow (CBF) via direct alpha-2-mediated constriction of cerebral blood vessels and indirectly via its effect on the intrinsic neural pathway modulating vascular smooth muscle. Reduction in CBF without a concomitant decrease in cerebral metabolic rate has raised concerns that DEX may limit adequate cerebral oxygenation of brain tissue in patients with already compromised cerebral circulation (e.g., carotid endarterectomy [CEA]). In this study, we established the incidence of intraarterial shunting used as a sign of inadequate oxygen delivery in a consecutive series of 123 awake CEA performed in our institution using DEX as a primary sedative. Data were prospectively recorded in 151 patients who underwent CEA during the study period. Eighteen patients were sedated with midazolam and fentanyl (M/F) for medical or logistical reasons. Patients thought to be at risk of an intraoperative stroke were treated with a prophylactic intraarterial shunt. These patients, as well as those who required general anesthesia, were excluded from the final analysis. Five patients (4.3%) in the DEX group required intraarterial shunts. The incidence of shunting in patient undergoing awake CEA in our institution is 10% (historical control). No patients developed a stroke or other serious complications. It appears that the use of DEX as a primary sedative drug for CEA does not increase the incidence of intraarterial shunts.
authors.affiliation: Department of Anesthesiology, New York University Medical Center, New York, New York, USA. alex.bekker@med.nyu.edu
authors.forename: Alex
authors.initials: A
authors.lastname: Bekker
authors.forename: Mark
authors.initials: M
authors.lastname: Gold
authors.forename: Raza
authors.initials: R
authors.lastname: Ahmed
authors.forename: Jung
authors.initials: J
authors.lastname: Kim
authors.forename: Caron
authors.initials: C
authors.lastname: Rockman
authors.forename: Glenn
authors.initials: G
authors.lastname: Jacobovitz
authors.forename: Thomas
authors.initials: T
authors.lastname: Riles
authors.forename: Gene
authors.initials: G
authors.lastname: Fisch
mesh_terms: D000368:Aged; D000714:Anastomosis, Surgical / Q000379:methods; D000765:Anesthesia, Conduction / Q000379:methods; D002343:Carotid Artery, Internal / Q000601:surgery; D002540:Cerebral Cortex / Q000098:blood supply; D020927:Dexmedetomidine / Q000009:adverse effects*; D016894:Endarterectomy, Carotid; D005260:Female; D006801:Humans; D006993:Hypnotics and Sedatives / Q000009:adverse effects*; D008297:Male; D011446:Prospective Studies; D014655:Vascular Resistance / Q000187:drug effects
chemical_list: D006993:Hypnotics and Sedatives; D020927:Dexmedetomidine