title: Effects of clonidine and superficial cervical plexus block on hemodynamic stability after carotid endarterectomy.
abstract: OBJECTIVE
  To evaluate the effects of 2 interventions (intravenous clonidine and superficial cervical block) on hemodynamic stability after carotid endarterectomy and to identify variables associated with hemodynamic instability.
  
  
  METHODS
  Prospective, observational study, sequential enrollment.
  
  
  METHODS
  University hospital.
  
  
  METHODS
  Two hundred seventy-five patients undergoing elective carotid endarterectomy under general anesthesia.
  
  
  METHODS
  Group NN (n = 50) received no intervention. In group CN (n = 85), 3 mug/kg of clonidine were administered intravenously 30 minutes before the end of the operation. Group CB (n = 140) additionally received a superficial cervical plexus block (SCB) with 20 mL of naropine 0.5% before the induction of anesthesia.
  
  
  RESULTS
  Clonidine alone (odds ratio [OR], 2.33; 95% confidence interval [CI], 1.45-3.76) and clonidine combined with an SCB (OR, 4.99; 95% CI, 3.19-7.82) resulted in a significant increase in hemodynamic stability after CEA (p < 0.001) from 53.3% (NN) to 70.0% (CN) and 83.3% (CB), respectively. The need for rescue medication decreased from 40.0% to 17.6% and 13.6% (p < 0.001). Both interventions significantly reduced the need for postoperative opioid analgesics (p < 0.01). Logistic regression analysis showed preoperative systolic blood pressure values greater than 170 mmHg (OR, 3.23; 95% CI, 1.76-5.93), previous cardiac interventions (OR, 3.3; 95% CI, 1.54-7.11), and the need for rescue medication in the awakening period (OR, 5.8; 95% CI, 2.88-11.52) to be independent risk factors for postoperative hemodynamic instability (p < or = 0.002).
  
  
  CONCLUSIONS
  Intravenous clonidine and superficial cervical block significantly improve cardiovascular stability after carotid endarterectomy. Patients with pre-existing excessive hypertension and previous coronary interventions must be considered a high-risk group.
authors.affiliation: Department of Anesthesiology and Intensive Care Medicine, University of Leipzig, Leipzig, Germany. jan.wallenborn@medizin.uni-leipzig.de
authors.forename: Jan
authors.initials: J
authors.lastname: Wallenborn
authors.forename: Volker
authors.initials: V
authors.lastname: Thieme
authors.forename: Gundi
authors.initials: G
authors.lastname: Hertel-Gilch
authors.forename: Katharina
authors.initials: K
authors.lastname: Gräfe
authors.forename: Olaf
authors.initials: O
authors.lastname: Richter
authors.forename: Lutz
authors.initials: L
authors.lastname: Schaffranietz
mesh_terms: D000368:Aged; D000959:Antihypertensive Agents / Q000494:pharmacology*; D001794:Blood Pressure / Q000187:drug effects; D002572:Cervical Plexus; D003000:Clonidine / Q000494:pharmacology*; D016894:Endarterectomy, Carotid / Q000009:adverse effects*; D005260:Female; D006439:Hemodynamics / Q000187:drug effects / Q000502:physiology; D006801:Humans; D006973:Hypertension / Q000517:prevention & control*; D007432:Intraoperative Period; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D009407:Nerve Block / Q000009:adverse effects / Q000379:methods; D016017:Odds Ratio; D011446:Prospective Studies; D012307:Risk Factors; D013997:Time Factors
chemical_list: D000959:Antihypertensive Agents; D003000:Clonidine