title: Effectiveness of preoperative beta-blockade on intra-operative heart rate in vascular surgery cases conducted under regional or local anesthesia.
abstract: BACKGROUND
  Preoperative β-blockade has been posited to result in better outcomes for vascular surgery patients by attenuating acute hemodynamic changes associated with stress. However, the incremental effectiveness, if any, of β-blocker usage in blunting heart rate responsiveness for vascular surgery patients who avoid general anesthesia remains unknown.
  
  
  METHODS
  We reviewed an existing database and identified 213 consecutive vascular surgery cases from 2005-2011 conducted without general anesthesia (i.e., under monitored anesthesia care or regional anesthesia) at a tertiary care Veterans Administration medical center and categorized patients based on presence or absence of preoperative β-blocker prescription. For this series of patients, with the primary outcome of maximum heart rate during the interval between operating room entry to surgical incision, we examined the association of maximal heart rate and preoperative β-blocker usage by performing crude and multivariate linear regression, adjusting for relevant patient factors.
  
  
  RESULTS
  Of 213 eligible cases, 137 were prescribed preoperative β-blockers, and 76 were not. The two groups were comparable across baseline patient factors and intraoperative medication doses. The β-blocker group experienced lower maximal heart rates during the period of evaluation compared to the non-β-blocker group (85 ± 22 bpm vs. 98 ± 36 bpm, respectively; p = 0.002). Adjusted linear regression confirmed a statistically-significant association between lower maximal heart rate and the use of β-blockers (Beta = -11.5; 95% CI [-3.7, -19.3] p = 0.004).
  
  
  CONCLUSIONS
  The addition of preoperative β-blockers, even when general anesthesia is avoided, may be beneficial in further attenuating stress-induced hemodynamic changes for vascular surgery patients.
authors.affiliation: Anesthesiology and Perioperative Care Service, Veterans Affairs Palo Alto Health Care System, 3801 Miranda Avenue, Palo Alto, CA 94304 USA ; Department of Anesthesiology, Perioperative, and Pain Medicine, Stanford University School of Medicine, Stanford, USA.
authors.forename: Seshadri C
authors.initials: SC
authors.lastname: Mudumbai
authors.affiliation: Center for Innovation to Implementation, Veterans Affairs Palo Alto Health Care System, Palo Alto, USA.
authors.forename: Todd
authors.initials: T
authors.lastname: Wagner
authors.affiliation: Department of Nursing, Veterans Affairs Palo Alto Health Care System, Palo Alto, USA.
authors.forename: Satish
authors.initials: S
authors.lastname: Mahajan
authors.affiliation: Anesthesiology and Perioperative Care Service, Veterans Affairs Palo Alto Health Care System, 3801 Miranda Avenue, Palo Alto, CA 94304 USA.
authors.forename: Robert
authors.initials: R
authors.lastname: King
authors.affiliation: Cardiology Service, Veterans Affairs Palo Alto Health Care System, Palo Alto, USA ; Department of Cardiology, Stanford University School of Medicine, Stanford, USA.
authors.forename: Paul A
authors.initials: PA
authors.lastname: Heidenreich
authors.affiliation: Department of Health Research and Policy and Department of Medicine (Cardiovascular Medicine), Stanford, USA.
authors.forename: Mark
authors.initials: M
authors.lastname: Hlatky
authors.affiliation: Anesthesia Service, San Francisco Veterans Affairs Medical Center, San Francisco, CA USA ; Department of Anesthesiology and Perioperative Care, University of California San Francisco, San Francisco, CA USA.
authors.forename: Arthur W
authors.initials: AW
authors.lastname: Wallace
authors.affiliation: Anesthesiology and Perioperative Care Service, Veterans Affairs Palo Alto Health Care System, 3801 Miranda Avenue, Palo Alto, CA 94304 USA ; Department of Anesthesiology, Perioperative, and Pain Medicine, Stanford University School of Medicine, Stanford, USA.
authors.forename: Edward R
authors.initials: ER
authors.lastname: Mariano
keywords: Effectiveness; General anesthesia; Heart rate; Monitored anesthesia care; Perioperative medicine; Regional anesthesia; Vascular surgery; β-blockers