title: The effect of remifentanil versus N(2)O on postoperative pain and emergence agitation after pediatric tonsillectomy/adenoidectomy.
abstract: BACKGROUND
  Remifentanil can be an alternative to N(2)O in general anesthesia. Intraoperative remifentanil may lead to acute opioid tolerance. This study aims to assess the effect of remifentanil substituted for 70% N(2)O on postoperative pain in children undergoing tonsillectomy/adenoidectomy. In addition, we evaluated the effect of remifentanil infusion on incidence of emergence agitation in these patients.
  
  
  METHODS
  Eighty children, aged 2-12 years, undergoing tonsillectomy/adenoidectomy were randomly allocated to the N(2)O group (Group N; n = 40, sevoflurane and 70% N(2)O) or remifentanil group (Group R; n = 40, sevoflurane with remifentanil infusion at the rate of 0.17 µg/kg/min). In the recovery room, severity of pain and agitation were assessed by an investigator blinded to the assigned group. Time to eye opening and incidence of severe pain and agitation were compared between groups. Logistic regression was used to identify factors related to occurrence of severe pain and agitation.
  
  
  RESULTS
  Number of patients with severe postoperative pain was 6 and 16 in groups N and R, respectively (P = 0.012). Incidence of emergence agitation was not significantly different between groups. Remifentanil infusion was a significant factor related to the occurrence of severe postoperative pain (P = 0.015), and age was inversely related to occurrence of emergence agitation (P = 0.001).
  
  
  CONCLUSIONS
  In children undergoing tonsillectomy/adenoidectomy, intraoperative remifentanil infusion may increase incidence of severe postoperative pain compared to N(2)O, but it may not affect incidence of emergence agitation.
authors.affiliation: Department of Anesthesiology and Pain Medicine, Seoul Paik Hospital, College of Medicine, Inje University, Seoul, Korea.
authors.forename: Hey-Ran
authors.initials: HR
authors.lastname: Choi
authors.forename: Jae Keun
authors.initials: JK
authors.lastname: Cho
authors.forename: Sangseok
authors.initials: S
authors.lastname: Lee
authors.forename: Byung Hoon
authors.initials: BH
authors.lastname: Yoo
authors.forename: Jun Heum
authors.initials: JH
authors.lastname: Yon
authors.forename: Kye-Min
authors.initials: KM
authors.lastname: Kim