title: Dose-dependent attenuation by fentanyl on cough during emergence from general anesthesia.
abstract: BACKGROUND
  Although fentanyl suppresses tracheal tube-induced cough during anesthetic recovery, it has not been proven if its antitussive effect is dose dependent and complication free. The purpose of this study is to evaluate the relationship between fentanyl doses and cough suppression during emergence from sevoflurane anesthesia.
  
  
  METHODS
  Sixty patients undergoing thyroidectomy were randomly allocated to one of four groups (F0, F1, F1.5, and F2) according to the fentanyl dose (0 mcg/kg, 1 mcg/kg, 1.5 mcg/kg, or 2 mcg/kg). Fentanyl was administered immediately after sevoflurane discontinuation. Coughing was assessed throughout the periextubation period. The relationship between fentanyl dose and incidence of cough was analyzed using Cochran-Armitage trend test. Incidence of more than 30% elevation of mean arterial pressure (MAP) and heart rate (HR), awakening time, extubation time, and respiratory rate after extubation were recorded and compared using Mantel-Haenszel chi-square test and one-way analysis of variance.
  
  
  RESULTS
  Fentanyl suppressed emergence cough in a dose-related manner (P = 0.002), and the ED(50) and ED(90) were 1.1 mcg/kg and 2.1 mcg/kg, respectively. The higher dose of fentanyl further reduced the number of patient with MAP and HR elevation (P = 0.003 and 0.005, respectively). Awakening time (8.4 ± 1.9 min) in F2 was comparable with that in F1 and F1.5. Respiratory rate (9 ± 2 bpm) and extubation time (11.9 ± 1.8 min) in F2 were only different from those in F0 (13 ± 3 bpm and 10.4 ± 1.1 min, respectively).
  
  
  CONCLUSIONS
  Fentanyl suppressed cough in a dose-related manner during recovery from general sevoflurane anesthesia, and 2 mcg/kg may be considered as a proper dose.
authors.affiliation: Department of Anaesthesiology and Pain Medicine, Anaesthesia and Pain Research Institute, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Y-C
authors.initials: YC
authors.lastname: Yoo
authors.forename: S
authors.initials: S
authors.lastname: Na
authors.forename: J-J
authors.initials: JJ
authors.lastname: Jeong
authors.forename: E-M
authors.initials: EM
authors.lastname: Choi
authors.forename: B-E
authors.initials: BE
authors.lastname: Moon
authors.forename: J-R
authors.initials: JR
authors.lastname: Lee
mesh_terms: D000328:Adult; D060666:Airway Extubation; D000762:Anesthesia Recovery Period; D000768:Anesthesia, General / Q000009:adverse effects*; D018685:Anesthetics, Inhalation; D018686:Anesthetics, Intravenous / Q000008:administration & dosage / Q000627:therapeutic use*; D001794:Blood Pressure / Q000187:drug effects; D003371:Cough / Q000209:etiology / Q000517:prevention & control*; D004305:Dose-Response Relationship, Drug; D005260:Female; D005283:Fentanyl / Q000008:administration & dosage / Q000627:therapeutic use*; D006339:Heart Rate / Q000187:drug effects; D006439:Hemodynamics / Q000187:drug effects; D006801:Humans; D008297:Male; D008738:Methyl Ethers; D008875:Middle Aged; D011183:Postoperative Complications / Q000517:prevention & control*; D015656:Respiratory Mechanics; D000077149:Sevoflurane; D013964:Thyroid Neoplasms / Q000601:surgery; D013965:Thyroidectomy
chemical_list: D018685:Anesthetics, Inhalation; D018686:Anesthetics, Intravenous; D008738:Methyl Ethers; D000077149:Sevoflurane; D005283:Fentanyl