title: Chloral hydrate sedation for auditory brainstem response (ABR) testing in children: Safety and effectiveness.
abstract: BACKGROUND
  The auditory brainstem response (ABR) test is used to identify hearing loss and measure hearing thresholds of infants and children who cannot be tested using standard behavioral hearing testing methods. In order for the ABR to yield useful data, a child must be asleep throughout the duration of the test. In many centers, this is achieved through the use of a general anesthetic, with its inherent risks and costs. Since 2004, ABRs have been routinely conducted at BC Children's Hospital in an ambulatory care setting under oral chloral hydrate sedation, with monitoring by a specialist nurse. The aim of this retrospective study was to assess the effectiveness and safety of nurse-led sedation with chloral hydrate for ABR testing at our tertiary pediatric center.
  
  
  METHODS
  Medical and audiology records were reviewed for children aged 6 months to 17 years who underwent ABR testing from 2004 to 2012. We reviewed the dosage of drug used, condition of the child after chloral hydrate administration, adverse effects, audiological results, patients' vital signs, and the effectiveness of the sedative in keeping the child asleep throughout the duration of the test. Frequency distributions were derived for adverse outcomes.
  
  
  RESULTS
  725 ABR records encompassing 635 children (multiple ABR tests in some children) were reviewed. The average dose of chloral hydrate used was 52mg/kg. The majority of sedated ABR's (80.8%) were completed without any incident. Significant events [apnea and/or bradycardia], minor complications [vomiting, hypoxemia, prolonged sedation, and/or tachypnea] and restlessness were noted in 3.4%, 6.2%, and 5.0% of the cases, respectively. The majority of these issues resolved without medical intervention, such as the need to provide supplementary oxygen. In 95.9% of ABRs, chloral hydrate was successful in sedating the child adequately to answer the audiological question.
  
  
  CONCLUSIONS
  This forms the largest study to date on oral sedation for ABR testing. Based on our results, the use of chloral hydrate in the presence of a sedation nurse was a safe and reliable method of performing ABR in infants and children. This may be of significant value to centres worldwide exploring alternatives to general anesthesia for ABR testing.
authors.affiliation: University of British Columbia, Faculty of Medicine, 317-2194 Health Sciences Mall, Vancouver, BC, Canada V6 T 1Z3.
authors.forename: Dianne G
authors.initials: DG
authors.lastname: Valenzuela
authors.affiliation: University of British Columbia, Faculty of Medicine, 317-2194 Health Sciences Mall, Vancouver, BC, Canada V6 T 1Z3.
authors.forename: Divjot Singh
authors.initials: DS
authors.lastname: Kumar
authors.affiliation: British Columbia Children's Hospital, Division of Pediatric Otolaryngology-Head and Neck Surgery, BC Children's Hospital, 4480 Oak Street, Vancouver, BC, Canada V6H 3V4.
authors.forename: Cheryl Labelle
authors.initials: CL
authors.lastname: Atkins
authors.affiliation: British Columbia Children's Hospital, Department of Audiology, BC Children's Hospital, Room K2-191, 4480 Oak Street, Vancouver, BC, Canada V6H 3V4.
authors.forename: Alison
authors.initials: A
authors.lastname: Beers
authors.affiliation: University of British Columbia, Faculty of Medicine, 317-2194 Health Sciences Mall, Vancouver, BC, Canada V6 T 1Z3; British Columbia Children's Hospital, Division of Pediatric Otolaryngology-Head and Neck Surgery, BC Children's Hospital, 4480 Oak Street, Vancouver, BC, Canada V6H 3V4.
authors.forename: Frederick K
authors.initials: FK
authors.lastname: Kozak
authors.affiliation: University of British Columbia, Faculty of Medicine, 317-2194 Health Sciences Mall, Vancouver, BC, Canada V6 T 1Z3; British Columbia Children's Hospital, Division of Pediatric Otolaryngology-Head and Neck Surgery, BC Children's Hospital, 4480 Oak Street, Vancouver, BC, Canada V6H 3V4. Electronic address: nchadha@cw.bc.ca.
authors.forename: Neil K
authors.initials: NK
authors.lastname: Chadha
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D002697:Chloral Hydrate / Q000008:administration & dosage* / Q000009:adverse effects; D054810:Deep Sedation / Q000009:adverse effects / Q000379:methods; D016057:Evoked Potentials, Auditory, Brain Stem / Q000187:drug effects*; D005260:Female; D034381:Hearing Loss / Q000175:diagnosis*; D006776:Hospitals, Pediatric; D006801:Humans; D006993:Hypnotics and Sedatives / Q000008:administration & dosage* / Q000009:adverse effects; D007223:Infant; D008297:Male; D012189:Retrospective Studies
chemical_list: D006993:Hypnotics and Sedatives; D002697:Chloral Hydrate
keywords: ABR; Children; Chloral hydrate; Hearing loss; Sedation