Mild hypohydration increases the frequency of driver errors during a prolonged, monotonous driving task.

Unlabelled: The aim of the present study was to examine the effect of mild hypohydration on performance during a prolonged, monotonous driving task.

Methods: Eleven healthy males (age 22±4y) were instructed to consume a volume of fluid in line with published guidelines (HYD trial) or 25% of this intake (FR trial) in a crossover manner. Participants came to the laboratory the following morning after an overnight fast.

Driver sleepiness-comparisons between young and older men during a monotonous afternoon simulated drive.

Young men figure prominently in sleep-related road crashes. Non-driving studies show them to be particularly vulnerable to sleep loss, compared with older men. We assessed the effect of a normal night's sleep vs.

Moderate sleep restriction in treated older male OSA participants: greater impairment during monotonous driving compared with controls.

Objectives: To examine the effects on monotonous driving of normal sleep versus one night of sleep restriction in continuous positive airway pressure (CPAP) treated obstructive sleep apnoea (OSA) patients compared with age matched healthy controls.

Methods: Nineteen CPAP treated compliant male OSA patients (OSA-treated patients (OPs)), aged 50-75 years, and 20 healthy age-matched controls underwent both a normal night's sleep and sleep restriction to 5h (OPs remained on CPAP) in a counterbalanced design. All participants completed a 2h afternoon monotonous drive in a realistic car simulator.

One night's CPAP withdrawal in otherwise compliant OSA patients: marked driving impairment but good awareness of increased sleepiness.

Purpose: Obstructive sleep apnoea (OSA) patients effectively treated by and compliant with continuous positive air pressure (CPAP) occasionally miss a night's treatment. The purpose of this study was to use a real car interactive driving simulator to assess the effects of such an occurrence on the next day's driving, including the extent to which these drivers are aware of increased sleepiness.

Methods: Eleven long-term compliant CPAP-treated 50-75-year-old male OSA participants completed a 2-h afternoon, simulated, realistic monotonous drive in an instrumented car, twice, following one night: (1) normal sleep with CPAP and (2) nil CPAP.

Early evening low alcohol intake also worsens sleepiness-related driving impairment.

Following night-time sleep restriction, afternoon driving performance during the bi-circadian surge in afternoon sleepiness is markedly worsened by blood alcohol concentrations (BACs) well under most national driving limits. This study assessed how driving with this same sleep restriction and BACs (av 40 mg and 28 mg alcohol/100 ml blood at the beginning and end of drive, respectively) respond during the evening circadian rise in alertness. In a 2 x 2 (alcohol versus control drink [double blind] x normal night sleep versus sleep restricted), repeated-measures design, eight healthy young men drove for 2 h from 18:00 h, in a real-car simulator, on a monotonous, simulated highway.

Sleepiness combined with low alcohol intake in women drivers: greater impairment but better perception than men?

Objectives: We have previously shown that low blood alcohol concentrations (BAC) (at approximately half the legal driving limit in both the United Kingdom and in most states in the United States) exacerbate moderate sleepiness (sleep during the night restricted to 5 hours) and markedly impair driving ability in young men. There are distinct physiologic sex differences in the absorption, metabolism, and central nervous system effects of alcohol; therefore, we replicated this earlier study, this time using women and using similar BAC to provide a comparison.

Design: 2 x 2 repeated-measures counterbalanced.