According to the American College of Occupational and Environmental Medicine CDME Training Course Syllabus and FMCSA Frequently Asked Questions (FAQs):
- “A person is physically qualified to drive a commercial motor vehicle if that person has no established medical history or clinical diagnosis of a respiratory dysfunction likely to interfere with his/her ability to control and drive a commercial motor vehicle safely.”
- “The guidelines recommend disqualifying a Commercial Motorized Vehicle driver with a diagnosis of Narcolepsy, regardless of treatment because of the likelihood of excessive daytime somnolence.”
- “Drivers should be disqualified until the diagnosis of sleep apnea has been ruled out or has been treated successfully.”
- “A driver with a diagnosis of (probable) sleep apnea or a driver who has Excessive Daytime Somnolence should be temporarily disqualified until the condition is either ruled out by objective testing or successfully treated.
- “As a condition of continuing qualification, it is recommended that a CMV driver agree to continue uninterrupted therapy such as CPAP, etc. monitoring and undergo objective testing as required.”
- “The examiner should consider general certification criteria at the initial and follow-up examinations:
- Severity and frequency of excessive daytime Somnolence (EDS).
- Presence or absence of warning of attacks.
- Possibility of sleep during driving.
- Degree of symptomatic relief with treatment.
- Compliance with treatment.”
In February of 2012, the Motor Carrier Safety Advisory Committee (Industry Group) and the FMCSA Medical
Review Board issued joint recommendations for guidance for motor carriers, CMV drivers, and medical examiners on OSA and subsequent determinations of a driver’s ability to operate a CMV safely. These recommendations are not yet regulations but are being reviewed and considered by the FMCSA. We consider the recommendations to reflect the current best practice in the medical evaluation and certification of CMV drivers with respect to OSA. The report can be found through the FMCSA website. We will be using this standard of care when we examine your drivers.
The International Classification of Sleep Disorders, Second Edition lists 81 official sleep disorders. Obstructive Sleep Apnea and Narcolepsy account for over 70% of excessive daytime somnolence (EDS) among Commercial Motor Vehicle Drivers. Sleep Apnea affects more than 18 million Americans, and most are unaware of the presence of the disorder. The Federal Motor Carrier Safety Administration (FMCSA) Medical Expert Panel (MEP) has concluded that “CMV drivers with OSA are at an increased risk for a crash when compared to their counterparts who do not have the disorder.”
The American Society of Sleep Medicine (ASSM) defines these two diagnoses as follows:
- Obstructive Sleep Apnea “is a sleep related breathing disorder that causes your body to stop breathing during sleep. OSA occurs when the tissue in the back of the throat collapses and blocks the airway. These keeps air from getting in to the lungs. This is a very common sleep disorder. It happens because the muscles inside the throat relax as you sleep. Gravity then causes the tongue to fall back and block the airway. Blockage of the airway can happen a few times per night or several hundred times per night.” The disease is most common in obese middle-aged men.
- Narcolepsy. The term Narcolepsy is used to describe a group of people affected by excessive sleepiness. It also includes features of dreaming that occur while awake. Narcoleptics are often refreshed by short naps. However, after two or three hours, they feel sleepy again. At times, people with Narcolepsy can fall asleep suddenly. These ‘sleep attacks’ can happen while eating, walking or driving.”
Our focus in this article is Obstructive Sleep Apnea (OSA) because it is far more common among commercial motor vehicle drivers, and may be a contributing cause to the development of several serious medical conditions.
Obstructive sleep apnea has been associated with:
- High blood pressure.
- Heart disease.
- Brain injury.
- Overall mortality.
- Memory problems.
All of these are conditions of concern for the commercial motor vehicle driver. As a result, it is critically important for drivers to be screened for the presence of OSA and referred for the appropriate diagnostic work-up and treatment, if indicated.
According to The American College of Chest Physicians (ACCP), the following are risk factors for the development of sleep apnea:
- Obesity (Please see the companion article in this edition).
- Age greater than 40.
- Family genetics.
- Small or misshapen upper airways.
- Large tonsils.
- Significant overbite or a recessed chin.
- African-Americans, Pacific-Islanders and Hispanics have more cases of sleep apnea per population than other ethnic groups but the reasons behind this are not clear.
- Alcohol Use.
The ACCP cites common symptoms of OSA, including:
- Witnessed pauses in breathing.
- Frequent awakenings.
- Fatigue and chronic tiredness.
- Difficulty staying awake during the day.
- Falling asleep at inappropriate times.
- Morning headaches.
- Memory or learning problems, difficulty concentrating.
- Irritability, depression, mood swings and changes in personality.
The FMCSA and all professional organizations recommend a detailed evaluation when OSA is suspected. This work-up includes:
- Sleep Study, also called a Polysomnogram (PSG). This is considered the diagnostic study of choice. It is performed overnight in a sleep laboratory. When there is a high likelihood of OSA, a split-night sleep study may be performed. This combines a standard PSG for purposes of confirming the diagnosis with a therapeutic trial of Continuous Positive Airway Pressure (CPAP) to determine the optimal setting for the CPAP mask or nasal prongs.
- At home sleep studies. While this is an option, it is not the preferred method for commercial motor vehicle drivers as it often underestimates the severity of the OSA.
- Overnight oxygen monitoring. This is a simple screening test to determine if the driver experiences decreased oxygen levels during sleep. It does not establish a specific diagnosis other than low oxygen levels during sleep. A PSG would still be required.
Once the diagnosis of OSA is established, treatment is required for the commercial motor vehicle driver to be certified to drive. The most common treatments include:
- Lifestyle changes such as weight loss, avoiding alcohol, smoking cessation and sleeping on one’s side.
- Continuous Positive Airway Pressure (CPAP) Therapy. This is the most common and effective therapy for OSA. The appliance delivers appropriate pressure to the airway to keep it open during inspiration and expiration. The appropriate pressure is determined at the time of the sleep study. Most new machines include a downloadable memory chip to monitor compliance and effectiveness. Drivers will need to demonstrate 4 hours or more of usage on at least 70% of nights to demonstrate “adequate” compliance.
- Oral appliances.
- Surgery such as soft tissue reduction or implants, jaw surgery or tracheostomy.
- Medications (rarely).
John D Charbonneau, MD, MPH, FACOEM