title: Effects of alcohol and sleep restriction on simulated driving performance in untreated patients with obstructive sleep apnea.
abstract: BACKGROUND
  Because of previous sleep disturbance and sleep hypoxia, patients with obstructive sleep apnea (OSA) might be more vulnerable to the effects of alcohol and sleep restriction than healthy persons.
  
  
  OBJECTIVE
  To compare the effects of sleep restriction and alcohol on driving simulator performance in patients with OSA and age-matched control participants.
  
  
  METHODS
  Driving simulator assessments in 2 groups under 3 different conditions presented in random order.
  
  
  METHODS
  Adelaide Institute for Sleep Health, Sleep Laboratory, Adelaide, Australia.
  
  
  METHODS
  38 untreated patients with OSA and 20 control participants.
  
  
  METHODS
  Steering deviation, crashes, and braking reaction time.
  
  
  METHODS
  Unrestricted sleep, sleep restricted to a maximum of 4 hours, and ingestion of an amount of 40% vodka calculated to achieve a blood alcohol level of 0.05 g/dL.
  
  
  RESULTS
  Patients with OSA demonstrated increased steering deviation compared with control participants (mean, 50.5 cm [95% CI, 46.1 to 54.9 cm] in the OSA group and 38.4 cm [CI, 32.4 to 44.4 cm] in the control group; P < 0.01) and significantly greater steering deterioration over time (group by time interaction, P = 0.02). The increase in steering deviation after sleep restriction and alcohol was approximately 40% greater in patients with OSA than in control participants (group by condition interaction, P = 0.04). Patients with OSA crashed more frequently than control participants (1 vs. 24 participants; odds ratio [OR], 25.4; P = 0.03) and crashed more frequently after sleep restriction (OR, 4.0; P < 0.01) and alcohol consumption (OR, 2.3; P = 0.02) than after normal sleep. In patients with OSA, prolonged eye closure (>2 seconds) and microsleeps (> 2 seconds of theta activity on electroencephalography) were significant crash predictors (OR, 19.2 and 7.2, respectively; P < 0.01). Braking reaction time was slower after sleep restriction than after normal sleep (mean, 1.39 [SD, 0.06] seconds vs. 1.22 [SD, 0.04] seconds; P < 0.01) but not after alcohol consumption. No group differences were found.
  
  
  CONCLUSIONS
  Simulated driving was assessed rather than on-road driving.
  
  
  CONCLUSIONS
  Patients with OSA are more vulnerable than healthy persons to the effects of alcohol consumption and sleep restriction on various driving performance variables.
  
  
  BACKGROUND
  Australian National Health and Medical Research Council.
authors.affiliation: Repatriation General Hospital, University of Adelaide, Adelaide, SA 5041, Australia. andrew.vakulin@health.sa.gov.au
authors.forename: Andrew
authors.initials: A
authors.lastname: Vakulin
authors.forename: Stuart D
authors.initials: SD
authors.lastname: Baulk
authors.forename: Peter G
authors.initials: PG
authors.lastname: Catcheside
authors.forename: Nick A
authors.initials: NA
authors.lastname: Antic
authors.forename: Cameron J
authors.initials: CJ
authors.lastname: van den Heuvel
authors.forename: Jillian
authors.initials: J
authors.lastname: Dorrian
authors.forename: R Doug
authors.initials: RD
authors.lastname: McEvoy
mesh_terms: D000063:Accidents, Traffic; D000328:Adult; D000428:Alcohol Drinking / Q000009:adverse effects*; D001334:Automobile Driving; D016022:Case-Control Studies; D003198:Computer Simulation; D000431:Ethanol / Q000097:blood; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D017286:Polysomnography; D011930:Reaction Time; D020181:Sleep Apnea, Obstructive / Q000097:blood / Q000503:physiopathology*; D012892:Sleep Deprivation; D013647:Task Performance and Analysis
chemical_list: D000431:Ethanol