to Medical Examiners and Training Organizations Regarding Obstructive Sleep
The purpose of this bulletin is to remind healthcare professionals on FMCSA’s National Registry of Certified Medical Examiners (the National Registry) of the current physical
qualifications standard and advisory criteria concerning the respiratory system, specifically how the requirements apply to drivers that may have obstructive sleep apnea (OSA).
Qualifications Standard for Respiratory Conditions
FMCSA’s physical qualifications
standards prohibit individuals from receiving a medical examiner’s certificate
to operate commercial motor vehicles in interstate commerce if they have an
“established medical history or clinical diagnosis of a respiratory dysfunction
likely to interfere with his or her ability to control and drive a commercial motor
vehicle safely.” (49 CFR 391.41(b)(5)). OSA is considered a respiratory
dysfunction when there is a determination that it is likely to interfere with
the driver’s ability to operate safely because of the severity of the case.
OSA is a respiratory disorder
characterized by a reduction or cessation of breathing during sleep coupled
with symptoms such as excessive daytime sleepiness. Given this, OSA may
culminate in unpredictable and sudden incapacitation (e.g., falling asleep at
the wheel), thus contributing to the potential for crashes, injuries, and
During sleep, OSA blocks the
airway and prevents the individual from breathing up to dozens of times per
hour, awakening the sleeper. This means that the time in bed does not equal
time slept – in fact, eight hours of sleep with OSA can be less refreshing than
four hours of ordinary, uninterrupted sleep, posing serious cognitive and
neuropsychological risks. Moreover, someone without enough restorative sleep is
often unaware of impairments to a range of cognitive abilities such as
vigilance, reaction time, attention span, memory, learning, problem-solving,
decision making, and multi-tasking. OSA can also lead to mood swings and
difficulty controlling inappropriate feelings. In driving simulations, OSA
patients were more likely to unintentionally swerve and strike objects – a
serious and dangerous outcome for the transportation industry.
OSA raises health and safety
concerns beyond those of other sleep disorders. Near-term increases in fatigue
and cognitive dysfunction can result. Also, there are long-term adverse health
effects such as dramatically increased risk for hypertension, heart disease,
stroke, diabetes, and obesity.
FMCSA’s Advisory Criteria
In 2000, FMCSA issued advisory
criteria providing interpretive guidance to medical examiners concerning its
physical qualifications standards. These advisory criteria are recommendations
from FMCSA to assist medical examiners in applying the minimum physical
qualification standards. The advisory criteria have been published with the
Federal Motor Carrier Safety Regulations as part of the medical examination
report form in 49 CFR 391.43 (Physical Qualification of Drivers; Medical
Examination; Certificate, 65 FR 59363 (October 5, 2000)).
The advisory criterion for §
391.41(b)(5), which has been unchanged since 2000, provides the following
guidance for medical examiners in making the determination whether a driver
satisfies the respiratory standard:
Since a driver must be alert at
all times, any change in his or her mental state is in direct conflict with
highway safety. Even the slightest impairment in respiratory function under
emergency conditions (when greater oxygen supply is necessary for performance) may
be detrimental to safe driving.
There are many conditions that
interfere with oxygen exchange and may result in incapacitation, including
emphysema, chronic asthma, carcinoma, tuberculosis, chronic bronchitis and
sleep apnea. If the medical examiner detects a respiratory dysfunction, that in
any way is likely to interfere with the driver’s ability to safely control and
drive a commercial motor vehicle, the driver must be referred to a specialist
for further evaluation and therapy. Anticoagulation therapy for deep vein
thrombosis and/or pulmonary thromboembolism is not unqualifying once optimum
dose is achieved, provided lower extremity venous examinations remain normal
and the treating physician gives a favorable recommendation.
Based on the above advisory
criterion, it is clear that FMCSA has considered OSA a respiratory dysfunction
that interferes with oxygen exchange. And the Agency recommends that, if a
medical examiner believes the driver’s respiratory condition is in any way
likely to interfere with the driver’s ability to safely control and drive a
commercial motor vehicle, the driver should be referred to a specialist for
further evaluation and therapy. This advisory criterion is helpful to medical
examiners when the examiner has sufficient experience or information to
recognize certain risk factors for OSA, or when a driver tells the examiner
that he or she has been diagnosed with OSA. Under these circumstances, the
medical examiner should consider referring the driver to a specialist for
evaluation before issuing a medical examiner’s certificate, or request
additional information from the driver and his or her treating healthcare
professional about the management of the driver’s OSA, respectively.
Role of Medical Examiners’
Clinical Judgment in the Medical Certification Process
FMCSA’s physical qualifications
standards and advisory criteria do not provide OSA screening, diagnosis or
treatment guidelines for medical examiners to use in determining whether an
individual should be issued a medical certificate. Medical examiners may
exercise their medical judgment and expertise in determining whether a driver
exhibits risk factors for having OSA and in determining whether additional
information is needed before making a decision whether to issue the driver a
medical certificate and the duration of that medical certification.
FMCSA urges medical examiners
to explain clearly to drivers the basis for their decision concerning the
issuance of a medical certification for a period of less than two years or the
denial of a medical certification.
The Agency encourages medical
examiners to consider the following in making the medical certification
• The primary safety goal regarding OSA is to identify drivers with
moderate-to-severe OSA to ensure these drivers are managing their condition
to reduce to the greatest extent practical the risk of drowsy driving.
Moderate-to-severe OSA is defined by an apnea-hypopnea index (AHI)1 of greater than
or equal to 15.
1 AHI = (apneas + hypopneas)/hours of sleep. Apnea is a term for the
involuntary suspension of breathing during sleep. During an apnea there is no
movement of the respiratory muscles and the volume of air in the lungs
initially remains unchanged. Hypopnea is a term for a disorder which involves episodes
of overly shallow breathing or an abnormally low respiratory rate. This differs
from apnea in that there remains some flow of air. Hypopnea events may happen
while asleep or while awake.
• The Agency does not require
that these drivers be considered unfit to continue their driving careers; only
that the medical examiner make a determination whether they need to be
evaluated and, if warranted, demonstrate they are managing their OSA to reduce
the risk of drowsy driving.
• Screening: With
regard to identifying drivers with undiagnosed OSA, FMCSA’s regulations and
advisory criteria do not include screening guidelines. Medical examiners should consider common OSA symptoms such as loud
snoring, witnessed apneas, or sleepiness during the major wake periods, as well
as risk factors, and consider multiple risk factors such as body mass index
(BMI), neck size, involvement in a single-vehicle crash, etc.
• Diagnosis: Methods
of diagnosis include in-laboratory polysomnography, at-home polysomnography, or
other limited channel ambulatory testing devices which ensure chain of custody.
• Treatment: OSA
is a treatable condition, and drivers with moderate-to-severe OSA can manage
the condition effectively to reduce the risk of drowsy driving. Treatment options range from weight loss to
dental appliances to Continuous Positive Airway Pressure (CPAP) therapy, and
combinations of these treatments. The Agency’s regulations and advisory
criteria do not include recommendations for treatments for OSA and FMCSA
believes the issue of treatment is best left to the treating healthcare
professional and the driver.
FMCSA relies on
medical examiners to make driver qualification decisions based on their
clinical observations, findings and standards of practice. The current
regulations and advisory criteria do not include guidelines concerning OSA
screening, diagnosis and treatment. Medical examiners should rely upon their
medical training and expertise in determining whether a driver exhibits
symptoms and/or multiple risk factors for OSA, and they should explain to the
driver the basis for their decision if the examiner decides to