By Jeffrey P. Barasch, M.D., FACCP, FAASMMedical DirectorThe Center for Sleep Medicine at The Valley Hospital

Newswise — The recent catastrophic NJ Transit train accident in Hoboken highlights one of the perils of undiagnosed sleep apnea – the threat to transportation safety. As in several other recent calamitous accidents, the engineer fell asleep at the wheel due to a medical condition that causes sleepiness, and the presence of which he was not aware. When an individual operates a vehicle of public transportation, whether it be a train, a bus or a plane, many lives are in their hands. Anytime the operator of one of these modes of transportation becomes drowsy, or worse, falls asleep at the controls, many lives are immediately placed in jeopardy. This is why these safety-critical personnel should be screened and monitored for their fitness for their work, including identifying the presence of sleep disorders. In fact, the Federal Railroad Administration is expected to issue a safety advisory this week stressing the importance of sleep apnea screening and treatment.

One of the most prevalent and serious of these conditions is obstructive sleep apnea. This is a serious, potentially life-threatening breathing disorder that affects an estimated 20 million Americans, most of whom remain undiagnosed. “Apnea” is a Greek word meaning “without breath.” Those with sleep apnea have pauses in their breathing during sleep, caused by a temporary collapse of the airway. Each episode of apnea, which can last from 10 seconds to over a minute, leads to reduced oxygen levels in the blood. This can occur dozens to hundreds of times during each night of sleep, and can lead to disruptions in sleep and frequent fluctuations in heart rate and blood pressure.

Untreated sleep apnea can seriously impair health and is linked to strokes, high blood pressure and heart attacks, which are otherwise unexplained. Additionally, sleep apnea can lead to arrhythmias, congestive heart failure, diabetes, and weight gain. Untreated sleep apnea can also lead to more frequent medical complications following surgery or anesthesia, as well as impaired job performance, errors and accidents.

More common in men than in women, sleep apnea is characterized by the following signs and symptoms: • Loud snoring • Periods of non-breathing during sleep, which may be accompanied by snorting or gasping sounds • Restless sleep or repetitive arousals, often unnoticed, during sleep • Feeling sleepy or falling asleep at inappropriate times during the day, such as while driving, working or reading. • Depression, irritability and sexual dysfunction • Memory loss.

The screening for sleep apnea in safety-critical personnel involves identifying people at especially high risk to have the disorder, such as people who are overweight and those with larger than average neck size (above 16” for women and 17” for men). However, not every person with sleep apnea will be identified by these physical attributes, and so it important that people be honest and realistic when assessing their own symptoms, especially daytime drowsiness. Daytime sleepiness or drowsiness is not a matter of whether one remains awake while physically active, or can forcibly keep awake with stimulation, but rather whether one tends to drift off, or their eyes want to close, when they are fully and completely relaxed.

Screening tests for sleep apnea include take home devices that monitor breathing and oxygen levels during sleep (Home Sleep Apnea Test, or HSAT). These can be useful and cost-effective in many cases. However, the ‘gold standard’ for definitively diagnosing, or ruling out, the presence of sleep apnea is an overnight test in a sleep center known as polysomnography, often dubbed a ‘sleep test’. This comprehensive test monitors and records multiple signals from the body, including sleep stage, mini-awakenings, breathing, heart beat, body and eye movements, oxygen levels and more, which enables a thorough evaluation of the quality of sleep and the presence of sleep apnea or other disorders. If you suspect you may have sleep apnea, ask your doctor if you could benefit from a sleep evaluation.