title: Pupillometry: a non-invasive technique for pain assessment in paediatric patients.
abstract: OBJECTIVE
  Pupillometry has been used to assess pain intensity and response to analgesic medications in adults. The aim of this observational study was to explore proof of concept for the use of this technique in paediatric patients. Changes in pupil parameters before and after opioid exposure also were evaluated.
  
  
  METHODS
  This was a single-centre, prospective study conducted at an academic paediatric medical centre.
  
  
  METHODS
  Children 9-17 years of age undergoing elective surgical correction of pectus excavatum were enrolled into a protocol approved by the human ethical committee (institutional review board).
  
  
  METHODS
  Pupil size and reactivity were measured using a handheld pupillometer. Pain was assessed using age-appropriate, validated pain self-report scales.
  
  
  RESULTS
  Thirty patients were enrolled. Each point change on a 10 cm visual analogue pain intensity scale was associated with a statistically significant mean change of 0.11 mm/s in maximum pupil constriction velocity, and of approximately 0.4% in pupil diameter. As expected, there was an association between total opioid dose (expressed as morphine equivalents) and pupil diameter. Age, sex and baseline anxiety scores did not correlate significantly with pupillary response.
  
  
  CONCLUSIONS
  The association of maximum pupillary constriction velocity and diameter with pain scores illustrates the potential for using pupillometry as a non-invasive method to objectively quantitate pain response/intensity in children. The technique holds promise as a pharmacodynamic 'tool' to assess opioid response in paediatric patients.
authors.affiliation: Departments of Pediatrics, University of Missouri-Kansas City, Kansas City, Missouri, USA Department of Developmental and Behavioral Sciences, The Children's Mercy Hospital, Kansas, Missouri, USA.
authors.forename: Mark A
authors.initials: MA
authors.lastname: Connelly
authors.affiliation: Divisions of Clinical Pharmacology, The Children's Mercy Hospital, Kansas, Missouri, USA.
authors.forename: Jacob T
authors.initials: JT
authors.lastname: Brown
authors.affiliation: Departments of Pediatrics, University of Missouri-Kansas City, Kansas City, Missouri, USA Divisions of Clinical Pharmacology, The Children's Mercy Hospital, Kansas, Missouri, USA Department of Pharmacology, The University of Missouri, Kansas, Missouri, USA.
authors.forename: Gregory L
authors.initials: GL
authors.lastname: Kearns
authors.affiliation: Divisions of Clinical Pharmacology, The Children's Mercy Hospital, Kansas, Missouri, USA.
authors.forename: Rawni A
authors.initials: RA
authors.lastname: Anderson
authors.affiliation: Departments of Pediatrics, University of Missouri-Kansas City, Kansas City, Missouri, USA Department of Surgery, The University of Missouri, Kansas, Missouri, USA Center for Prospective Surgery Research, the Children's Mercy Hospital, Kansas, Missouri, USA.
authors.forename: Shawn D
authors.initials: SD
authors.lastname: St Peter
authors.affiliation: Departments of Pediatrics, University of Missouri-Kansas City, Kansas City, Missouri, USA Divisions of Clinical Pharmacology, The Children's Mercy Hospital, Kansas, Missouri, USA Department of Pharmacology, The University of Missouri, Kansas, Missouri, USA Department of Hematology and Oncology, The Children's Mercy Hospital, Kansas, Missouri, USA.
authors.forename: Kathleen A
authors.initials: KA
authors.lastname: Neville
mesh_terms: D000293:Adolescent; D000701:Analgesics, Opioid / Q000627:therapeutic use*; D002648:Child; D003941:Diagnostic Techniques, Ophthalmological / Q000295:instrumentation*; D005260:Female; D006801:Humans; D008297:Male; D010146:Pain / Q000188:drug therapy* / Q000503:physiopathology; D010147:Pain Measurement / Q000379:methods*; D011446:Prospective Studies; D011680:Pupil / Q000187:drug effects*; D012025:Reflex, Pupillary / Q000502:physiology*
chemical_list: D000701:Analgesics, Opioid
keywords: Analgesia; Pain; Pharmacology; Technology