title: Performance impairment during four days partial sleep deprivation compared with the acute effects of alcohol and hypoxia.
abstract: OBJECTIVE
  Subjects were exposed to cumulated partial sleep deprivation (psd), alcohol intake and hypoxia in a sequential design to examine the impact on neurobehavioral performance.
  
  
  METHODS
  Sixteen healthy male volunteers were enrolled in this study and were exposed in turn, after adaptation and baseline measurements, to one day of periods of hypoxia, one day of alcohol intake and one day for recovering (with 8h time in bed TIB). Subsequently the exposition of those conditions is that the subjects spent 5h night restriction daily for four consecutive days, followed by two recovery days. Performance was tested five (or six) times per day with reaction time task (SRT) and unstable tracking task (UTT).
  
  
  RESULTS
  The performance impairment showed to be cumulative in both tests over the four sleep deprivation days and differed significantly from baseline. Corresponding performance deficits under the influence of the stressors were for SRT: four days psd, 13% O(2) concentration and a blood alcohol concentration (BAC) of around 0.4-0.6 per thousand for UTT: four days psd, 13% O(2) concentration and a BAC of around 0.6 per thousand. One night of 8h sleep restored performance nearly to baseline level.
  
  
  CONCLUSIONS
  A sleeping time of 5h per night for four consecutive days impairs performance in such a way that traffic safety may be compromised.
authors.affiliation: Institute of Aerospace Medicine, DLR, German Aerospace Centre, 51170 Cologne, Germany. d.elmenhorst@fz.juelich.de
authors.forename: David
authors.initials: D
authors.lastname: Elmenhorst
authors.forename: Eva-Maria
authors.initials: EM
authors.lastname: Elmenhorst
authors.forename: Norbert
authors.initials: N
authors.lastname: Luks
authors.forename: Hartmut
authors.initials: H
authors.lastname: Maass
authors.forename: Ernst-Wilhelm
authors.initials: EW
authors.lastname: Mueller
authors.forename: Martin
authors.initials: M
authors.lastname: Vejvoda
authors.forename: Juergen
authors.initials: J
authors.lastname: Wenzel
authors.forename: Alexander
authors.initials: A
authors.lastname: Samel
mesh_terms: D000328:Adult; D000435:Alcoholic Intoxication / Q000150:complications / Q000503:physiopathology / Q000523:psychology*; D006801:Humans; D000860:Hypoxia / Q000150:complications / Q000503:physiopathology / Q000523:psychology*; D008297:Male; D011597:Psychomotor Performance / Q000502:physiology*; D011930:Reaction Time; D020127:Recovery of Function; D012307:Risk Factors; D012892:Sleep Deprivation / Q000150:complications / Q000503:physiopathology* / Q000523:psychology*; D013997:Time Factors; D055815:Young Adult