title: Ketamine as an adjunct to fentanyl improves postoperative analgesia and hastens discharge in children following tonsillectomy - a prospective, double-blinded, randomized study.
abstract: OBJECTIVE
  To evaluate the effect of ketamine, as an adjunct to fentanyl, on postoperative analgesia and duration of Postoperative Care Unit (PACU) stay, in children undergoing tonsillectomy.
  
  
  BACKGROUND
  Ketamine, as an N-methyl-d-aspartate antagonist, has been recognized to have an opioid sparing effect. In addition, it does not depress respiration or affect airway tone. Hence, addition of ketamine could be potentially beneficial in children undergoing tonsillectomy, due to the high incidence of sleep apnea in these patients.
  
  
  METHODS
  In a double blinded, randomized trial, 60 ASA status I and II children between 2 and 7 years of age, scheduled to undergo elective tonsillectomy were recruited. They were randomly assigned to one of four groups to receive fentanyl 1 mcg·kg(-1) (F1 group), fentanyl 2 mcg·kg(-1) (F2 group), ketamine 0.5 mg·kg(-1) (K group), or fentanyl 1 mcg·kg(-1) plus ketamine 0.5 mg·kg(-1) (FK group) pre-incision. Postoperative pain was scored on arrival to the PACU and at 30, 60, and 90 min thereafter. Any incidence of nausea/vomiting and time to discharge from the PACU were also recorded.
  
  
  RESULTS
  Important predictors found for postoperative pain on arrival to the recovery room are the group (P = 0.02) and duration of surgery (P = 0.02). Least square means and standard errors of pain scores on PACU arrival were 4.87±0.69, 3.04±0.68, 2.10±0.68 and 2.03±0.69 for F1, F2, K and FK groups, respectively. On group-wise comparison adjusted for surgical time, significant difference was detected between F1 and K (P = 0.02), and F1 and FK (P = 0.0048) groups. Marginal significance was detected in duration of PACU stay among groups (P = 0.08); F2 and FK group had a shorter PACU stay than F1 (P = 0.05 and 0.04 respectively). No significant difference was detected in the need for supplemental analgesia.
  
  
  CONCLUSIONS
  We conclude that the administration of ketamine 0.5 mg·kg(-1) with 1 mcg·kg(-1) fentanyl in children undergoing tonsillectomy may improve postoperative pain control without delaying home discharge.
authors.affiliation: Department of Anesthesia, Brookdale University Hospital and Medical Center, Brooklyn, NY, USA.
authors.forename: Nabil
authors.initials: N
authors.lastname: Elshammaa
authors.forename: Vidya
authors.initials: V
authors.lastname: Chidambaran
authors.forename: Walaa
authors.initials: W
authors.lastname: Housny
authors.forename: Joan
authors.initials: J
authors.lastname: Thomas
authors.forename: Xue
authors.initials: X
authors.lastname: Zhang
authors.forename: Rafik
authors.initials: R
authors.lastname: Michael
mesh_terms: D000762:Anesthesia Recovery Period; D000768:Anesthesia, General; D000778:Anesthetics, Dissociative; D018686:Anesthetics, Intravenous; D002648:Child; D002675:Child, Preschool; D004311:Double-Blind Method; D005260:Female; D005283:Fentanyl; D006801:Humans; D007649:Ketamine; D007902:Length of Stay; D008297:Male; D010147:Pain Measurement / Q000187:drug effects; D010149:Postoperative Pain / Q000517:prevention & control*; D010351:Patient Discharge; D020250:Postoperative Nausea and Vomiting / Q000453:epidemiology; D011446:Prospective Studies; D014068:Tonsillectomy
chemical_list: D000778:Anesthetics, Dissociative; D018686:Anesthetics, Intravenous; D007649:Ketamine; D005283:Fentanyl