title: The preventative analgesic effect of preincisional peritonsillar infiltration of two low doses of ketamine for postoperative pain relief in children following adenotonsillectomy. A randomized, double-blind, placebo-controlled study.
abstract: BACKGROUND
  In literature, the use of ketamine for the preventative analgesia in the management of postoperative pain is controversial. The purpose of the present study was the clinical assessment of the efficacy of preincisional peritonsillar infiltration of two doses of ketamine on postoperative pain relief compared with peritonsillar saline in children undergoing adenotonsillectomy.
  
  
  METHODS
  Seventy-five ASA physical status I and II patients, aged 3-12 years, scheduled for adenotonsillectomy were enrolled in this randomized, double-blind, placebo-controlled study. Patients were divided into three groups of 25 each and received a local peritonsillar infiltration of 0.9% saline (group S), ketamine 0.5 mg x kg(-1) (group K1), or ketamine 1 mg x kg(-1) (group K2). All medications were 2 ml in volume which was applied 1 ml per tonsil 3 min prior to tonsillectomy. The Children's Hospital of Eastern Ontario Pain Scale (CHEOPS) and Wilson sedation scale were used to evaluate pain levels and sedative conditions, respectively.
  
  
  RESULTS
  Group S had significantly higher CHEOPS scores than group K1 and K2. Both K1 and K2 groups had comparable scores, which were not statistically significant (P > 0.05). During 24 h after surgery, 16 patients in group S and no patients in groups K1 or K2 needed analgesics (P < 0.001).
  
  
  CONCLUSIONS
  A 0.5 or 1 mg.kg(-1) dose of ketamine given at approximately 3 min before surgery by peritonsillar infiltration provides efficient pain relief during 24 h after surgery without side-effects in children undergoing adenotonsillectomy.
authors.affiliation: Department of Anesthesiology and Intensive Care, Isfahan University of Medical sciences, Isfahan, Iran. honarmand@med.mui.ac.ir
authors.forename: Azim
authors.initials: A
authors.lastname: Honarmand
authors.forename: Mohammad Reza
authors.initials: MR
authors.lastname: Safavi
authors.forename: Majid
authors.initials: M
authors.lastname: Jamshidi
mesh_terms: D000233:Adenoidectomy; D000700:Analgesics / Q000008:administration & dosage*; D000772:Anesthesia, Local / Q000379:methods*; D002648:Child; D002675:Child, Preschool; D004305:Dose-Response Relationship, Drug; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D007649:Ketamine / Q000008:administration & dosage*; D008297:Male; D010147:Pain Measurement / Q000379:methods / Q000706:statistics & numerical data; D010149:Postoperative Pain / Q000209:etiology / Q000517:prevention & control*; D017060:Patient Satisfaction; D011446:Prospective Studies; D012965:Sodium Chloride / Q000008:administration & dosage; D013997:Time Factors; D014068:Tonsillectomy; D016896:Treatment Outcome
chemical_list: D000700:Analgesics; D012965:Sodium Chloride; D007649:Ketamine