title: Adverse events and behavioral reactions related to ketamine based anesthesia for anorectal manometry in children.
abstract: BACKGROUND
  Pediatric patients undergoing anorectal manometry require ketamine anesthesia as other anesthetic agents affect the anorectal sphincter tone. The aim of this prospective observational audit was to evaluate our practice and report the occurrence of adverse events and behavioral reactions related to the use of ketamine, propofol, and midazolam combinations.
  
  
  METHODS
  Eighty-two consecutive pediatric patients (mean age 8.06 +/- 3.43 years) undergoing anorectal manometry were audited over a 1-year period. After a routine ketamine anesthetic some children were administered midazolam 0.1 mg.kg(-1), at the discretion of the attending anesthetist. Children requiring anal stretch following manometry studies also received propofol 3-5 mg.kg(-1). Intra- and postoperative adverse events, times to spontaneous awakening and discharge from the PACU were noted. Postoperative behavioral reactions were noted in the PACU and at follow-up interviews on the first postoperative day and after a period of 1 month.
  
  
  RESULTS
  Following completion of the audit, all patients fell into one of the four groups depending on the anesthetic agents they received: K (ketamine only, n = 16), KM (ketamine and midazolam, n = 10), KP (ketamine and propofol, n = 27), and KPM (ketamine, propofol, and midazolam, n = 29). There was no difference in the occurrence of behavioral reactions between the four groups at the three stages of follow-up. Overall, five patients reported 'new onset' nightmares that had resolved completely at the 3-month follow-up. The time to spontaneous awakening was shorter for K group (17.8 min +/- 20.2) vs KPM group (61.7 min +/- 24.4; P < 0.001). The times to discharge in minutes was also shorter in the K group (54.5 min, IQR 30-75 vs 90 min IQR 78-120; P < 0.001). Administration of propofol appeared to have an antiemetic effect [odds ratio (OR) 0.1, 95% confidence intervals (CI) 0.02-0.58, P < 0.009] in the recovery unit.
  
  
  CONCLUSIONS
  Our study findings suggest that, besides significantly prolonging time to spontaneous awakening and PACU discharge, neither the use of midazolam, propofol, or combinations is beneficial in preventing the occurrence of behavioral reactions following ketamine anesthesia. Behavioral reactions were common but did not appear to be long-term. Drug combinations with ketamine may have other benefits such as antiemesis.
authors.affiliation: Department of Anesthesia, Penn State Milton Hershey Medical Center College of Medicine, Hershey, PA 17033, USA. pdalal@hmc.psu.edu
authors.forename: Priti G
authors.initials: PG
authors.lastname: Dalal
authors.forename: Dan
authors.initials: D
authors.lastname: Taylor
authors.forename: Nicola
authors.initials: N
authors.lastname: Somerville
authors.forename: Neena
authors.initials: N
authors.lastname: Seth
mesh_terms: D001003:Anal Canal / Q000187:drug effects; D000762:Anesthesia Recovery Period; D000771:Anesthesia, Intravenous; D019162:Anesthetics, Combined / Q000008:administration & dosage; D000778:Anesthetics, Dissociative / Q000008:administration & dosage / Q000009:adverse effects*; D018686:Anesthetics, Intravenous / Q000008:administration & dosage; D002648:Child; D004244:Dizziness / Q000139:chemically induced; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007649:Ketamine / Q000008:administration & dosage / Q000009:adverse effects*; D008297:Male; D008365:Manometry / Q000009:adverse effects / Q000523:psychology; D008485:Medical Audit; D008874:Midazolam / Q000008:administration & dosage; D020184:Night Terrors / Q000139:chemically induced; D020250:Postoperative Nausea and Vomiting / Q000139:chemically induced; D015742:Propofol / Q000008:administration & dosage; D011446:Prospective Studies; D012007:Rectum / Q000187:drug effects; D016896:Treatment Outcome
chemical_list: D019162:Anesthetics, Combined; D000778:Anesthetics, Dissociative; D018686:Anesthetics, Intravenous; D007649:Ketamine; D008874:Midazolam; D015742:Propofol