title: Effect of a single dose of esmolol on the bispectral index to endotracheal intubation during desflurane anesthesia.
abstract: BACKGROUND
  In this prospective, randomized, double-blind, placebo-controlled trial, we investigated the effect of a single dose of esmolol on the bispectral index (BIS) to endotracheal intubation during desflurane anesthesia.
  
  
  METHODS
  After induction of anesthesia, 60 patients were mask-ventilated with desflurane (end-tidal 1 minimum alveolar concentration) for 5 min and then received either normal saline, esmolol 0.5 or 1 mg/kg, 1 min prior to intubation (control, esmolol-0.5 and esmolol-1 groups, n = 20/group). BIS, mean arterial pressure, and heart rate were measured prior to anesthesia induction and esmolol administration, immediately preceding intubation (time point 0), and every minute for 5 min after intubation (time point 1 to 5). At time point 0, 1 and 5, 5 ml of arterial blood was taken to measure plasma concentrations of norepinephrine and epinephrine.
  
  
  RESULTS
  BIS increased significantly at 1 min after intubation when compared with pre-intubation values in all groups. Both mean arterial pressure and heart rate increased significantly 1 min after intubation when compared with preintubation values for all groups. Plasma epinephrine concentrations did not increase significantly after tracheal intubation in any of the groups. Norepinephrine increased at 1 min after intubation when compared with the preintubation values in the esmolol groups (P < 0.05).
  
  
  CONCLUSIONS
  A single bolus of esmolol was unable to blunt the increase in BIS to endotracheal intubation during desflurane anesthesia.
authors.affiliation: Department of Anesthesiology and Pain Medicine, Kangnam Sacred Heart Hospital, Hallym University College of Medicine, Seoul, Korea.
authors.forename: Eun Mi
authors.initials: EM
authors.lastname: Choi
authors.forename: Kyeong Tae
authors.initials: KT
authors.lastname: Min
authors.forename: Jeong Rim
authors.initials: JR
authors.lastname: Lee
authors.forename: Tai Kyung
authors.initials: TK
authors.lastname: Lee
authors.forename: Seung Ho
authors.initials: SH
authors.lastname: Choi
keywords: Bispectral index; Desflurane; Esmolol; Intubation; Norepinephrine