title: The interactive effects of extended wakefulness and low-dose alcohol on simulated driving and vigilance.
abstract: OBJECTIVE
  Sleep deprivation and alcohol both impair driving performance. This study assessed the interactive effect of low-dose alcohol and extended wakefulness.
  
  
  METHODS
  Repeated-measures, crossover design evaluating psychomotor and driving function in a non-sleep-deprived state and after extended wakefulness with and without low-dose alcohol.
  
  
  METHODS
  Teaching hospital sleep laboratory.
  
  
  METHODS
  Nineteen volunteer professional drivers.
  
  
  METHODS
  Driving simulation (AusEd) and the Psychomotor Vigilance Task (PVT) were measured in a rested state (12-15 hours awake) and after extended wakefulness (18-21 hours awake) during two sessions. Alcohol was administered during one session, with performance measured at blood alcohol concentrations (BAC) of 0.00%, 0.03%, and 0.05% in a non-sleep-deprived state, and at 0.03% after extended wakefulness (at 01:00 and 03:00). During the second session, tests were performed at the same times without alcohol.
  
  
  RESULTS
  The combination of extended wakefulness and low-dose alcohol had significant deleterious effects on reaction time and lapses (PVT) and variation in lane position and speed (AusEd). Extended wakefulness (18-21 hours awake) combined with low-dose alcohol (0.03% BAC) resulted in more lapses (t = -2.75, P < 0.05) and greater variation in lane position (t = -3.94, P < 0.01) and speed (t = -2.79, P < 0.05) than did a BAC of 0.05% in a rested state.
  
  
  CONCLUSIONS
  The combination of legal low-dose alcohol and extended wakefulness results in impairment worse than that at an alcohol level known to increase accident risk. Avoiding alcohol when driving after extended wakefulness may reduce accident risk.
authors.affiliation: Institute for Breathing & Sleep, Department of Respiratory & Sleep Medicine, Austin Health, Melbourne, Australia. mark.howard@austin.org.au
authors.forename: Mark E
authors.initials: ME
authors.lastname: Howard
authors.forename: Melinda L
authors.initials: ML
authors.lastname: Jackson
authors.forename: Gerard A
authors.initials: GA
authors.lastname: Kennedy
authors.forename: Philip
authors.initials: P
authors.lastname: Swann
authors.forename: Maree
authors.initials: M
authors.lastname: Barnes
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Pierce
mesh_terms: D000328:Adult; D000428:Alcohol Drinking / Q000503:physiopathology*; D000704:Analysis of Variance; D001334:Automobile Driving; D003198:Computer Simulation; D006801:Humans; D008297:Male; D008875:Middle Aged; D010468:Perceptual Disorders / Q000209:etiology / Q000503:physiopathology; D011930:Reaction Time; D016037:Single-Blind Method; D012892:Sleep Deprivation / Q000150:complications*; D013647:Task Performance and Analysis; D014851:Wakefulness / Q000502:physiology*