Author: Dr. Joseph Kraner, Singular Sleep
Sleep disorders are a major contributor to motor vehicle accidents. Driving after acute sleep deprivation (<5 hours) has been shown to increase the risk of motor vehicle crashes to the same degree as driving with a blood alcohol concentration at or slightly above the legal limit. Obstructive sleep apnea, or OSA, is a common medical problem caused by the repetitive collapse of the upper airway during sleep and has been found to increase the risk for MVAs by 2.5-5-fold. Commercial drivers face multiple obstacles to obtaining sufficient quality sleep including long work hours, suboptimal sleeping environments and irregular sleep schedules. What can you do to stay safe on the road?
Watch Your Hygiene
Sleep hygiene refers to good habits that promote healthy sleep. Commercial drivers often face environmental and other factors that predispose them to poor sleep hygiene. Ambient noise from outside your cab can ping your brain and prevent falling asleep or cause multiple brief awakenings during the night, negatively affecting your sleep quality. Try using white noise to help drown out disruptive environmental noise. There are numerous options: fans, air purifiers, smartphone apps, and devices made specifically for this purpose – I like the Dohm and Lectrofan.
Even minute amounts of light can stimulate your brain to wake up. Your sleeper berth should be “cave-like.” If that’s hard to achieve, try a quality sleep mask such as the Sleep Master. Speaking of light, avoid blue light for one-to-two hours before bed. It’s common for drivers to “wind down” by watching media on smartphones or tablets but this exposure to blue light in the evening can make it harder to fall and stay asleep. If you just can’t resist your iPad, use a blue-light dimming app, such as F.Lux. Also, be sure to keep your sleeping environment on the cool side.
It’s important to do your best to maintain a regular sleep schedule. This can be difficult due to work demands and, for some drivers, time zone changes. Try not to vary your bed and wake times by more than one hour. Keeping this schedule on your days off is best.
How Much Is Enough?
The research is clear that adults will achieve optimum alertness and long-term health if they consistently get at least seven hours of sleep per day. Chronic partial sleep deprivation of less than six hours per day has been associated with weight gain, type 2 diabetes, and increased rates of cardiovascular disease (heart disease and stroke). Obtaining seven-to-eight hours of sleep in a single, continuous period is ideal. If that’s impossible for you, making up your sleep deficit with naps to obtain that seven hour per day is the next best thing.
Pitfalls to Avoid
Trying to get the rest you need during your scheduled off-duty period can lead to “performance anxiety.” Alcohol and other substances are commonly used to help get to sleep at a desired time. However, be aware that these substances can be a net-negative for your sleep quality. Alcohol decreases the time it takes to fall asleep but, as you metabolize it during the night, wreaks havoc on your sleep during the latter part of your sleep period, causing frequent awakenings. Sedative-hypnotic medication such as Ambien, Lunesta, Xanax can help you fall and stay asleep but may stay in your system longer than anticipated, impairing your ability to drive. One research study found that Ambien metabolites stayed in your system for up to fourteen hours. Sedative-hypnotic medications and alcohol can also worsen sleep apnea Over-the-counter sleep medications typically contain Benadryl (diphenhydramine) or a similar sedating antihistamine. These medications can make you feel like you’re getting more sleep but reduce the amount of deep, restorative sleep leading to feeling groggy the next day. They can also make restless legs syndrome (see below) worse.
When to Get Help
In clinical practice, the two most common sleep disorders that lead to chronic sleep disruption and daytime sleepiness are sleep apnea and restless legs syndrome (RLS). The most common form of sleep apnea is obstructive sleep apnea (OSA) and typical risk factors are being overweight or obese, neck circumference (17” or more in men and 16” or more in women), smoking, alcohol and sedative/muscle relaxant use, age, male gender, and facial and jaw structure. In addition to an increased risk of motor vehicle crashes, OSA can cause daytime sleepiness, impaired memory and attention, depression, high blood pressure, heart disease, and stroke. Unfortunately, commercial drivers often have difficulty managing their weight due to multiple factors including a sedentary lifestyle and poor access to healthy meals while working. Weight is probably the main factor behind why commercial drivers tend to have higher rates of OSA than the general population. If your DOT provider suspects OSA, he or she may refer you to have a sleep study. A home sleep study may be a good option for drivers to save them the inconvenience and expense of an in-lab sleep study; home sleep studies have been shown to be equivalent to in-lab sleep studies for diagnosing OSA.
RLS is an uncomfortable feeling in the legs that manifests in the evening and is relieved by moving the legs around. Risk factors for RLS include diabetes, iron deficiency anemia, stimulant use (e.g. caffeine and nicotine), and genetics. RLS can get so bad that it can make it difficult to fall asleep. The majority of people with RLS also have repetitive leg movements during their sleep which can wake the brain up constantly and lead to daytime sleepiness. If you think that you might have OSA or RLS, make an appointment to talk with your doctor as both of these conditions are eminently treatable.