Sleepiness or drowsiness has frequently been associated with car accidents. The monotony of modern motorways, prolonged periods of driving day or night and the huge increase in road traffic combine to make drowsiness at the wheel an important public health issue. Several series from the USA and UK (see details in the paper) have established a high prevalence of sleepiness at the wheel and that a large proportion of accidents happen during times when there is normal tendency to sleep (2-5 am and 1-3 pm). Studies from the USA and Spain (see paper) have shown that the risk is particularly great in certain categories of driver - narcoleptics (though the authors have reservations about the evidence in this group), people with the syndrome of sleep apnoea, chronic insomniacs and possibly people taking anxiolytic drugs. Lorry drivers and shift workers are especially at risk during periods when normal circadian rhythms tend to induce sleep (again 2-5 am and 1-3 pm). Young drivers (18-25 year olds) constitute a large proportion of fatal accidents. The risk profile is of a young male driving fast at night during the week-end with a high level of alcohol in the blood. Also at special risk are people who drive long distances occasionally to go on holiday. What can be done to diminish risk? Besides advice on the necessity of periods of rest and the avoidance of alcohol, appropriate disease specific therapy is indicated when a specific disorder of sleep is diagnosed. Clinical scales, such as Epworth’s, allow an evaluation of the severity of drowsinesss. An iterative test of sleep latency and its corollary, a test of maintenance of wakefulness can be useful and are described in the paper. Finally and simply, all drivers should be told that humans have their own alarm signs - yawning, heaviness of the eyelids, loss of muscle tone and failures of attention that impose a need stop driving, to rest. (Author/publisher)
Abstract