title: Ultrasound-guided regional anesthesia for carotid endarterectomy induces early hemodynamic and stress hormone changes.
abstract: OBJECTIVE
  Locoregional anesthesia is an effective method for evaluating cerebral function during carotid endarterectomy (CEA). Landmark-guided regional anesthesia (RA) is currently used for CEA and can provoke substantial perioperative hypertension. Ultrasound-guided RA (US-RA) is a new method for performing RA in CEA; however, the effect on sympathetic activity and blood pressure is uncertain. This study assessed early sympathetic activity during CEA in US-RA compared with general anesthesia (GA).
  
  
  METHODS
  Patients were prospectively randomized to receive US-RA (n = 32) or GA (n = 28) for CEA. The primary end point was the change in systolic arterial blood pressure after induction of anesthesia (just before starting surgery) comparing US-RA with GA. We also recorded heart rate and analyzed concentrations of plasma blood hormones, including cortisol, metanephrine, and normetanephrine at five different times. Creatinine kinase, troponin I, and N-terminal pro-B-type natriuretic peptide were analyzed to detect potential changes in cardiac biomarkers during the procedure.
  
  
  RESULTS
  Systolic arterial blood pressure (mean ± standard deviation) increased significantly in US-RA patients compared with GA patients even before surgery was initiated (180 ± 26 mm Hg vs 109 ± 24 mm Hg; P < .001), then remained elevated during the entire surgery and returned to baseline values 1 hour after admission to the postoperative anesthesia care unit. Heart rate (US-RA: 78 ± 16 beats/min, GA: 52 ± 12 beats/min; P < .001) and cortisol levels (US-RA: 155 ± 97 μg/L, GA: 99 ± 43 μg/L; P = .006) were also significantly higher in the US-RA group after induction of anesthesia. Other values did not differ.
  
  
  CONCLUSIONS
  The US-RA technique for CEA induces temporary intraoperative hypertension and an increase in stress hormone levels. Nevertheless, US-RA is a feasible, effective, and safe form of locoregional for CEA that enables targeted placement of low volumes of local anesthesia under direct visualization.
authors.affiliation: Department of Anesthesiology and Critical Care Medicine, Medical University of Innsbruck, Innsbruck, Austria.
authors.forename: Judith
authors.initials: J
authors.lastname: Hoefer
authors.affiliation: Department of Anesthesiology and Critical Care Medicine, Medical University of Innsbruck, Innsbruck, Austria.
authors.forename: Eve
authors.initials: E
authors.lastname: Pierer
authors.affiliation: Department of Vascular Surgery, Medical University of Innsbruck, Innsbruck, Austria.
authors.forename: Barbara
authors.initials: B
authors.lastname: Rantner
authors.affiliation: Department of Anesthesiology and Critical Care Medicine, Medical University of Innsbruck, Innsbruck, Austria.
authors.forename: Karl-Heinz
authors.initials: KH
authors.lastname: Stadlbauer
authors.affiliation: Department of Vascular Surgery, Medical University of Innsbruck, Innsbruck, Austria.
authors.forename: Gustav
authors.initials: G
authors.lastname: Fraedrich
authors.affiliation: Department of Medical Statistics, Informatics and Health Economics, Medical University of Innsbruck, Innsbruck, Austria.
authors.forename: Josef
authors.initials: J
authors.lastname: Fritz
authors.affiliation: Department of Anesthesiology and Critical Care Medicine, Medical University of Innsbruck, Innsbruck, Austria. Electronic address: axel.kleinsasser@i-med.ac.at.
authors.forename: Axel
authors.initials: A
authors.lastname: Kleinsasser
authors.affiliation: Department of Anesthesiology and Critical Care Medicine, Medical University of Innsbruck, Innsbruck, Austria.
authors.forename: Corinna
authors.initials: C
authors.lastname: Velik-Salchner
mesh_terms: D000368:Aged; D000765:Anesthesia, Conduction / Q000009:adverse effects / Q000379:methods*; D000768:Anesthesia, General / Q000009:adverse effects; D062186:Arterial Pressure; D001317:Austria; D015415:Biomarkers / Q000097:blood; D016894:Endarterectomy, Carotid / Q000009:adverse effects / Q000379:methods*; D005260:Female; D006339:Heart Rate; D006439:Hemodynamics; D006801:Humans; D006854:Hydrocortisone / Q000097:blood; D006973:Hypertension / Q000097:blood / Q000209:etiology* / Q000503:physiopathology; D008297:Male; D008676:Metanephrine / Q000097:blood; D008875:Middle Aged; D009647:Normetanephrine / Q000097:blood; D011446:Prospective Studies; D013312:Stress, Physiological; D013564:Sympathetic Nervous System / Q000378:metabolism / Q000503:physiopathology*; D013997:Time Factors; D016896:Treatment Outcome; D018084:Ultrasonography, Interventional / Q000009:adverse effects / Q000379:methods*
chemical_list: D015415:Biomarkers; D009647:Normetanephrine; D008676:Metanephrine; D006854:Hydrocortisone