title: Assessment of sleep in ventilator-supported critically III patients.
abstract: OBJECTIVE
  In critically ill patients, sleep derangements are reported to be severe using Rechtschaffen and Kales (R&K) methodology; however, whether such methodology can reliably assess sleep during critical illness is unknown. We set out to determine the reproducibility of 4 different sleep-assessment methods (3 manual and 1 computer-based) for ventilator-supported critically ill patients and also to quantify the extent to which the reproducibility of the manual methods for measuring sleep differed between critically ill and ambulatory (control) patients.
  
  
  METHODS
  Observational methodologic study.
  
  
  METHODS
  Academic center.
  
  
  METHODS
  Critically ill patients receiving mechanical ventilation and age-matched controls underwent polysomnography.
  
  
  METHODS
  None.
  
  
  RESULTS
  Reproducibility for the computer-based method (spectral analysis of electroencephalography [EEG]) was better than that for the manual methods: R&K methodology and sleep-wakefulness organization pattern (P = 0.03). In critically ill patients, the proportion of misclassifications for measurements using spectral analysis, sleep-wakefulness organization pattern, and R&K methodology were 0%, 36%, and 53%, respectively (P < 0.0001). The EEG pattern of burst suppression was not observed. Interobserver and intraobserver reliability of the manual sleep-assessment methods for critically ill patients (kappa = 0.52 +/- 0.23) was worse than that for control patients (kappa = 0.89 +/- 0.13; P = 0.03). In critically ill patients, the overall reliability of the R&K methodology was relatively low for assessing sleep (kappa = 0.19), but detection of rapid eye movement sleep revealed good agreement (kappa = 0.70).
  
  
  CONCLUSIONS
  Reproducibility for spectral analysis of EEG was better than that for the manual methods: R&K methodology and sleep-wakefulness organization pattern. For assessment of sleep in critically ill patients, the use of spectral analysis, sleep-wakefulness organization state, or rapid eye movement sleep alone may be preferred over the R&K methodology.
authors.affiliation: Section of Pulmonary, Critical Care, and Sleep Medicine, Southern Arizona VA Health Care System, Tucson, AZ 85723, USA.
authors.forename: Cristina
authors.initials: C
authors.lastname: Ambrogio
authors.forename: Jeffrey
authors.initials: J
authors.lastname: Koebnick
authors.forename: Stuart F
authors.initials: SF
authors.lastname: Quan
authors.forename: Marco
authors.initials: M
authors.lastname: Ranieri
authors.forename: Sairam
authors.initials: S
authors.lastname: Parthasarathy
mesh_terms: D000208:Acute Disease; D000368:Aged; D000369:Aged, 80 and over; D016638:Critical Illness; D004569:Electroencephalography; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D017286:Polysomnography / Q000379:methods*; D012121:Respiration, Artificial; D012131:Respiratory Insufficiency / Q000453:epidemiology* / Q000628:therapy*; D012720:Severity of Illness Index; D012894:Sleep Stages / Q000502:physiology; D012893:Sleep Wake Disorders / Q000175:diagnosis* / Q000453:epidemiology* / Q000503:physiopathology; D014743:Videotape Recording