title: Clonidine for major vascular surgery in hypertensive patients: a double-blind, controlled, randomized study.
abstract: The utility of clonidine for hypertensive patients presenting for major vascular procedures remains debatable. Twenty-one hypertensive patients presenting for aortic surgery were given clonidine (n = 11) or placebo (n = 10) in a double-blind, randomized manner. Clonidine was administered 6 micrograms/kg per os 120 min before induction of anesthesia and 3 micrograms/kg intravenously (i.v.) over 60 min from aortic declamping to skin closure. Anesthesia was induced with alfentanil 20 micrograms/kg, midazolam, and atracurium and maintained with nitrous oxide 70%, an alfentanil infusion (0.25 microgram.kg-1. min-1), and isoflurane. Anesthetic requirements, circulatory variables, interventions, and isoproterenol dose-response curves (pre- and postoperatively) were determined. Plasma concentrations of clonidine, alfentanil, and vasoactive hormones were measured. When the clonidine group was compared with the placebo group, (a) isoflurane, alfentanil, and midazolam requirements were reduced by 38%, 42%, and 41%, respectively (P = 0.04, 0.03, 0.0002, respectively); (b) supplemental circulatory and anesthetic adjustments were reduced by 51% (P = 0.0006); (c) interventions with vasopressors were not significantly increased (placebo: two; clonidine: five); (d) systolic and mean arterial pressures and heart rate were reduced; (e) increases in norepinephrine, epinephrine, and plasma renin activity were suppressed, whereas vasopressin surge was attenuated; and (f) chronotropic response to isoproterenol was unaffected. Clonidine was effective in reducing anesthetic requirements and in improving circulatory stability in hypertensive patients presenting for major vascular procedures.
authors.affiliation: Department of Anesthesia, Hôpital Nord, St. Etienne, France.
authors.forename: L
authors.initials: L
authors.lastname: Quintin
authors.forename: X
authors.initials: X
authors.lastname: Bouilloc
authors.forename: E
authors.initials: E
authors.lastname: Butin
authors.forename: M C
authors.initials: MC
authors.lastname: Bayon
authors.forename: J R
authors.initials: JR
authors.lastname: Brudon
authors.forename: J C
authors.initials: JC
authors.lastname: Levron
authors.forename: H
authors.initials: H
authors.lastname: Tassan
authors.forename: C
authors.initials: C
authors.lastname: Boucaud
authors.forename: S
authors.initials: S
authors.lastname: Tissot
authors.forename: B
authors.initials: B
authors.lastname: Frehring
authors.forename: P
authors.initials: P
authors.lastname: Petit
authors.forename: T
authors.initials: T
authors.lastname: Danays
authors.forename: J P
authors.initials: JP
authors.lastname: Viale
authors.forename: M
authors.initials: M
authors.lastname: Ghignone
mesh_terms: D000284:Administration, Oral; D000328:Adult; D015760:Alfentanil / Q000008:administration & dosage / Q000097:blood; D018685:Anesthetics, Inhalation / Q000008:administration & dosage; D018686:Anesthetics, Intravenous / Q000008:administration & dosage / Q000097:blood; D000959:Antihypertensive Agents / Q000008:administration & dosage / Q000097:blood / Q000627:therapeutic use*; D001018:Aortic Diseases / Q000601:surgery*; D001775:Blood Circulation / Q000187:drug effects; D002316:Cardiotonic Agents / Q000008:administration & dosage / Q000627:therapeutic use; D003000:Clonidine / Q000008:administration & dosage / Q000097:blood / Q000627:therapeutic use*; D004305:Dose-Response Relationship, Drug; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D007275:Injections, Intravenous; D007430:Intraoperative Care; D007530:Isoflurane / Q000008:administration & dosage; D007545:Isoproterenol / Q000008:administration & dosage / Q000627:therapeutic use; D008297:Male; D008874:Midazolam / Q000008:administration & dosage; D008875:Middle Aged; D010919:Placebos; D011292:Premedication; D014662:Vasoconstrictor Agents / Q000008:administration & dosage
chemical_list: D018685:Anesthetics, Inhalation; D018686:Anesthetics, Intravenous; D000959:Antihypertensive Agents; D002316:Cardiotonic Agents; D010919:Placebos; D014662:Vasoconstrictor Agents; D015760:Alfentanil; D007530:Isoflurane; D007545:Isoproterenol; D003000:Clonidine; D008874:Midazolam