Effects of alcohol and sleep restriction on simulated driving performance in untreated patients with obstructive sleep apnea

© 2009 American College of PhysiciansBackgroundBecause 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.ObjectiveTo compare the effects of sleep restriction and alcohol on driving simulator performance in patients with OSA and age-matched control participants.DesignDriving simulator assessments in 2 groups under 3 different conditions presented in random order.SettingAdelaide Institute for Sleep Health, Sleep Laboratory, Adelaide, Australia.Participants38 untreated patients with OSA and 20 control participants.MeasurementsSteering deviation, crashes, and braking reaction time.InterventionUnrestricted 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.ResultsPatients 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 2 seconds) and microsleeps (> 2 seconds of theta activity on electroencephalography) were significant crash predictors (OR, 19.2 and 7.2, respectively; P LimitationSimulated driving was assessed rather than on-road driving.ConclusionPatients with OSA are more vulnerable than healthy persons to the effects of alcohol consumption and sleep restriction on various driving performance variables.Primary funding sourceAustralian National Health and Medical Research Council.Andrew Vakulin, Stuart D. Baulk, Peter G. Catcheside, Nick A. Antic, Cameron J. van den Heuvel, Jillian Dorrian and R. Doug McEvo