title: Intravenous esmolol infusion improves surgical fields during sevoflurane-anesthetized endoscopic sinus surgery: a double-blind, randomized, placebo-controlled trial.
abstract: BACKGROUND
  There is increasing evidence to support the use of anesthetics to affect operative fields during endoscopic sinus surgery and thus the speed, thoroughness, and safety of the surgery itself. Previous research has suggested preoperative beta-blockers improve surgical  fields (SFs); our study is novel in showing the impact of a beta-blocker infusion on SFs during sinus surgery.
  
  
  METHODS
  A prospective, randomized, double-blind, placebo-controlled trial was conducted in 40 patients. Patients undergoing endoscopic sinus surgery for chronic  rhinosinusitis received a constant infusion of i.v. esmolol or saline in addition to a standard inhaled anesthetic protocol. At regular 15-minutes intervals, the quality of SF, heart rate (HR), systolic blood pressure (SBP), and diastolic blood pressure (DBP) were assessed. Total blood loss  was also recorded.
  
  
  RESULTS
  Average vital sign parameters (HR/SBP/DBP) were significantly lower in the esmolol group (69.1/90.2/55.1 versus 77.2/99.5/63.5; p < 0.01). The esmolol infusion improved SFs relative to control (2.3 versus 2.6; p = 0.045). Esmolol infusion  resulted in good SFs (grades 1 and 2) more often than poor fields (grades 3 and 4); on the contrary, the control group showed more poor than good SFs (chi-square; p = 0.04). A correlation between increasing HR and worsening SFs was identified (r = 0.259; p = 0.002). The control group had significantly  higher average blood loss (1.3 versus 0.8 mL/min; p = 0.037).
  
  
  CONCLUSIONS
  Esmolol-induced relative hypotension and bradycardia during endoscopic sinus surgery achieves significantly improved SFs relative to saline control.
authors.affiliation: Department of Otolaryngology, Kuang-Tien General Hospital, Taichung, Taiwan.
authors.forename: Ping-Hung
authors.initials: PH
authors.lastname: Shen
authors.forename: Erik Kent
authors.initials: EK
authors.lastname: Weitzel
authors.forename: Jen-Tsung
authors.initials: JT
authors.lastname: Lai
authors.forename: Peter-John
authors.initials: PJ
authors.lastname: Wormald
authors.forename: Chee-Sang
authors.initials: CS
authors.lastname: Ho
mesh_terms: D000759:Adjuvants, Anesthesia; D000293:Adolescent; D000319:Adrenergic beta-Antagonists / Q000008:administration & dosage* / Q000009:adverse effects; D000328:Adult; D000368:Aged; D000769:Anesthesia, Inhalation; D016063:Blood Loss, Surgical; D001794:Blood Pressure / Q000187:drug effects; D002648:Child; D002908:Chronic Disease; D004311:Double-Blind Method; D004724:Endoscopy; D005260:Female; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D007262:Infusions, Intravenous; D008297:Male; D008738:Methyl Ethers / Q000627:therapeutic use; D008875:Middle Aged; D010256:Paranasal Sinuses / Q000473:pathology / Q000601:surgery; D011412:Propanolamines / Q000008:administration & dosage* / Q000009:adverse effects; D012220:Rhinitis / Q000503:physiopathology / Q000628:therapy*; D000077149:Sevoflurane; D012852:Sinusitis / Q000503:physiopathology / Q000628:therapy*
chemical_list: D000759:Adjuvants, Anesthesia; D000319:Adrenergic beta-Antagonists; D008738:Methyl Ethers; D011412:Propanolamines; D000077149:Sevoflurane; C036604:esmolol