title: Prophylactic esmolol infusion for the control of cardiovascular responses to extubation after intracranial surgery.
abstract: BACKGROUND
  Emergence from general anaesthesia and extubation are often accompanied by significant surges in heart rate and blood pressure. To document these changes and the efficacy of low-dose beta-blocker infusions in ameliorating these rises, we undertook a descriptive dose-ranging study comparing the use of esmolol to placebo in patients emerging from neuro-anaesthesia.
  
  
  METHODS
  Thirty-six patients undergoing intracranial surgery were randomised to receive saline, esmolol 100 micrograms/kg/min or 200 micrograms/kg/min infusions. The number of patients developing severe hypertension or tachycardia in each group was compared using Fisher's exact test.
  
  
  RESULTS
  Systolic blood pressure (SBP) and heart rate (HR) increased in all 3 groups during emergence and peaked at extubation. The proportion of patients with severe tachycardia or hypertension was reduced from 92% in the placebo group to 40% (P = 0.02) and 8% (P = 0.001) in the low and intermediate dose esmolol groups, respectively. Results were better in the intermediate dose group but the difference was not statistically significant. Two patients from the esmolol infusion groups required supplemental medication for bradycardia.
  
  
  CONCLUSIONS
  Severe hypertension or tachycardia occurs in 92% of patients during extubation following neuro-anaesthesia and warrants the consideration of routine prophylaxis. Prophylactic esmolol infusion for the control of haemodynamic disturbances during extubation is feasible and safe. A modest level of obtundation is evident at 100 micrograms/kg/min but a rate of 200 micrograms/kg/min may prove to be more effective.
authors.affiliation: Department of Anaesthesiology, Tan Tock Seng Hospital, Singapore. Siew_Hoon_Lim@notes.ttsh.gov.sg
authors.forename: S H
authors.initials: SH
authors.lastname: Lim
authors.forename: N M
authors.initials: NM
authors.lastname: Chin
authors.forename: H Y
authors.initials: HY
authors.lastname: Tai
authors.forename: M
authors.initials: M
authors.lastname: Wong
authors.forename: T K
authors.initials: TK
authors.lastname: Lin
mesh_terms: D000319:Adrenergic beta-Antagonists / Q000494:pharmacology / Q000627:therapeutic use*; D000328:Adult; D000368:Aged; D001794:Blood Pressure / Q000187:drug effects; D001927:Brain Diseases / Q000601:surgery*; D004305:Dose-Response Relationship, Drug; D016903:Drug Monitoring; D005260:Female; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D006973:Hypertension / Q000188:drug therapy* / Q000209:etiology* / Q000503:physiopathology; D007262:Infusions, Intravenous; D007275:Injections, Intravenous; D008297:Male; D008875:Middle Aged; D011412:Propanolamines / Q000494:pharmacology / Q000627:therapeutic use*; D013599:Systole / Q000187:drug effects; D013610:Tachycardia / Q000188:drug therapy* / Q000209:etiology* / Q000503:physiopathology; D015300:Ventilator Weaning / Q000009:adverse effects* / Q000295:instrumentation
chemical_list: D000319:Adrenergic beta-Antagonists; D011412:Propanolamines; C036604:esmolol