title: Determination of the 95% effective dose of remifentanil for the prevention of coughing during extubation in children undergoing tonsillectomy (with or without adenoidectomy).
abstract: BACKGROUND
  Limited data are available regarding the 95% effective dose (ED95 ) of remifentanil to prevent the cough response during emergence from general anesthesia in children.
  
  
  METHODS
  This study included 40 patients aged 3-12 years who underwent elective tonsillectomy with or without adenoidectomy. A predetermined remifentanil dose was infused continuously with desflurane during surgery and was continued until extubation. In the emergence period, the cough response during awake extubation was assessed to determine the remifentanil dose for the next patient. The first patient received remifentanil at the rate of 0.01 μg·kg(-1) ·min(-1) , and subsequent patients received a 0.01 μg·kg(-1) ·min(-1) higher dose than the previous patient if there was more than moderate coughing detected, and the patient after those with less than mild coughing received either the same dose (95% probability) or a 0.01 μg·kg(-1) ·min(-1) lower dose (5% probability) using the biased coin design. Times to extubation and adverse events were recorded. The ED95 was calculated using the maximum-likelihood estimation.
  
  
  RESULTS
  The ED95 of remifentanil for preventing coughing during extubation was 0.060 μg·kg(-1) ·min(-1) (95% confidence interval, 0.037-0.068). There was moderate coughing in all groups receiving 0.01-0.06 μg·kg(-1) ·min(-1) of remifentanil, but no cough response occurred in the group receiving remifentanil 0.07 μg·kg(-1) ·min(-1) . Time to extubation was weakly correlated with remifentanil infusion rate (r = 0.331). One patient who received remifentanil 0.07 μg·kg(-1) ·min(-1) showed desaturation over 5 s immediately after extubation, but recovered after receiving 100% oxygen.
  
  
  CONCLUSIONS
  The ED95 of the continuous remifentanil infusion rate was 0.060 μg·kg(-1) ·min(-1) to prevent the cough response during extubation in children after tonsillectomy.
authors.affiliation: Department of Anesthesiology and Pain Medicine, Chung-Ang University Hospital, Seoul, Korea.
authors.forename: Yong-Hee
authors.initials: YH
authors.lastname: Park
authors.forename: Eun-Jin
authors.initials: EJ
authors.lastname: Chung
authors.forename: Ji-Hyun
authors.initials: JH
authors.lastname: Lee
authors.forename: Jin-Tae
authors.initials: JT
authors.lastname: Kim
authors.forename: Chong-Sung
authors.initials: CS
authors.lastname: Kim
authors.forename: Hee-Soo
authors.initials: HS
authors.lastname: Kim
mesh_terms: D000233:Adenoidectomy; D060666:Airway Extubation; D018686:Anesthetics, Intravenous / Q000493:pharmacokinetics; D002648:Child; D002675:Child, Preschool; D003371:Cough / Q000517:prevention & control*; D004305:Dose-Response Relationship, Drug; D005260:Female; D006801:Humans; D008297:Male; D010880:Piperidines / Q000493:pharmacokinetics*; D000077208:Remifentanil; D014068:Tonsillectomy
chemical_list: D018686:Anesthetics, Intravenous; D010880:Piperidines; D000077208:Remifentanil
keywords: children; coughing; remifentanil; tonsillectomy