title: The relevance of pupillometry for evaluation of analgesia before noxious procedures in the intensive care unit.
abstract: BACKGROUND
  Many patients in the intensive care unit are unable to communicate verbally. Accurately predicting whether such patients will exhibit painful behaviors during noxious procedures and assessing the adequacy of analgesia during those procedures is a challenge. In addition to observational pain assessment tools such as the Behavioral Pain Scale, physiologic indicators such as the pupillary response have been proposed. The pupil is innervated by both divisions of the autonomic nervous system and is affected by pain and analgesic medications. We evaluated the pupillary response to a light stimulus before noxious procedures as a method to predict pain during the procedure.
  
  
  METHODS
  We correlated different aspects of the pupillary light reflex with established strategies for pain assessment to evaluate the adequacy of analgesia before surgical dressing changes performed in the intensive care unit in patients with cellulitis associated with mediastinitis or not.
  
  
  RESULTS
  We found that a percentage of variation in pupil size >19% predicted the presence of pain as assessed by a Behavioral Pain Scale score of >3 with a sensitivity of 100% (95% confidence interval, 100%-100%) and a specificity of 77% (95% confidence interval, 54%-100%).
  
  
  CONCLUSIONS
  In patients unable to communicate verbally, pupillometry may potentially guide caregivers to adjust analgesia before noxious procedures.
authors.affiliation: From the Department of Anesthesiology and Critical Care, Lariboisière Hospital, Univ Paris Diderot, Sorbonne Paris Cité, Paris, France.
authors.forename: Anne-Claire
authors.initials: AC
authors.lastname: Lukaszewicz
authors.forename: Domitille
authors.initials: D
authors.lastname: Dereu
authors.forename: Etienne
authors.initials: E
authors.lastname: Gayat
authors.forename: Didier
authors.initials: D
authors.lastname: Payen
mesh_terms: D000328:Adult; D000700:Analgesics / Q000627:therapeutic use*; D000891:Anti-Infective Agents, Local / Q000627:therapeutic use; D001458:Bandages; D002481:Cellulitis / Q000601:surgery*; D003646:Debridement; D004322:Drainage; D005260:Female; D006801:Humans; D007362:Intensive Care Units; D008027:Light; D008297:Male; D008480:Mediastinitis / Q000601:surgery*; D008875:Middle Aged; D010146:Pain / Q000175:diagnosis / Q000188:drug therapy* / Q000209:etiology / Q000503:physiopathology / Q000523:psychology; D010147:Pain Measurement / Q000379:methods*; D058748:Pain Perception / Q000187:drug effects; D010775:Photic Stimulation; D011182:Postoperative Care; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012025:Reflex, Pupillary / Q000187:drug effects* / Q000528:radiation effects
chemical_list: D000700:Analgesics; D000891:Anti-Infective Agents, Local