title: Toward a new approach for the detection of pain in adult patients undergoing cardiac surgery: near-infrared spectroscopy--a pilot study.
abstract: OBJECTIVE
  This pilot study examined the discriminant validity and criterion validity of regional cerebral oxygenation measurement (rSO₂), using the near-infrared spectroscopy (NIRS) technique (INVOS-4100 system, Somanetics, Troy, MI) for measuring pain during nociceptive procedures in adults undergoing cardiac surgery.
  
  
  METHODS
  A repeated-measures, within-subjects design was used, and 40 adult patients participated. Data collection was completed during 2 test periods: (1) while patients were awake, before the induction of anesthesia (first test period); and (2) after the induction of anesthesia, while patients remained under the effects of anesthesia (second test period). Each test period included a baseline, a tactile stimulus (skin disinfection), nociceptive stimuli (e.g., intravenous and arterial line insertions, sternal bone incision and thorax opening), and a postprocedure evaluation.
  
  
  RESULTS
  Increased rSO₂ values (P < .001) were acquired during nociceptive procedures in both test periods. No significant associations were evident between rSO₂, pain behaviors, and the patient's self-report of pain intensity, but this may be attributable to a low range of variability.
  
  
  CONCLUSIONS
  Although further research is needed in critically ill adult patients undergoing more painful procedures, the NIRS may become a promising technique for assessing pain.
authors.affiliation: School of Nursing, McGill University, Montreal, Quebec, Canada. celine.gelinas@mcgill.ca
authors.forename: Céline
authors.initials: C
authors.lastname: Gélinas
authors.forename: Manon
authors.initials: M
authors.lastname: Choinière
authors.forename: Manon
authors.initials: M
authors.lastname: Ranger
authors.forename: André
authors.initials: A
authors.lastname: Denault
authors.forename: Alain
authors.initials: A
authors.lastname: Deschamps
authors.forename: Celeste
authors.initials: C
authors.lastname: Johnston
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000758:Anesthesia / Q000379:methods; D002318:Cardiovascular Diseases / Q000150:complications* / Q000503:physiopathology / Q000601:surgery; D013504:Cardiovascular Surgical Procedures / Q000523:psychology*; D002560:Cerebrovascular Circulation; D003422:Critical Care; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009020:Morphine / Q000627:therapeutic use; D009294:Narcotics / Q000627:therapeutic use; D009619:Nociceptors; D010146:Pain / Q000175:diagnosis* / Q000209:etiology; D010147:Pain Measurement; D010865:Pilot Projects; D015203:Reproducibility of Results; D019265:Spectroscopy, Near-Infrared / Q000295:instrumentation / Q000379:methods*; D013223:Statistics as Topic
chemical_list: D009294:Narcotics; D009020:Morphine