Sleep apnea is a medical condition that may adversely affect an
individual’s quality of life and heath. The negative effects of sleep
apnea range from annoying to life threatening. For pilots and controllers,
sleep apnea may also compromise flying safety and may result in loss of
FAA medical certification.
Fortunately, the condition is treatable. Most people treated for sleep
apnea quickly notice a significant improvement in their quality of life.
More importantly, treatment minimizes risk factors for negative health
effects. Upon documentation of successful treatment, the FAA will consider
reinstatement of a pilot or controller’s medical certification.
The National Institutes of Health estimates that 18 million Americans have
sleep apnea. Approximately 4% of the adult population between ages 30 and
60 years has sleep apnea associated with daytime sleepiness. The estimated
percentages rise to 7% in adults over age 60. Most sleep apnea (80%) is
The prevalence is higher in men than in women. According to the New
England Journal of Medicine, 16% of men and 22% of women have chronic
daytime sleepiness alone, while 24% of adult men and 9% of adult women
meet objective criteria for apnea while sleeping.
The FAA granted 1555 Special Issuance medical certificates (First Class =
279, Second Class = 335, Third Class = 1041) for successfully treated
sleep apnea as of November 2003.
What is Sleep Apnea?
Sleep apnea is a potentially serious, and possibly life-threatening,
condition resulting from interference or interruption of breathing when
sleeping. Sleep is fragmented and is of poor quality. Most people with
sleep apnea are unaware that they have this condition, although their bed
partners are likely to have noticed some of the symptoms.
The syndrome was first described in the medical literature in 1965.
However, within the last decade, the seriousness and potential
complications of this disease are now being recognized. Interestingly,
Charles Dickens described a character with massive obesity, snoring,
disturbed sleep, a flushed face and daytime sleepiness in his novel, “The
Pickwick Papers”. As a result, sleep apnea is often referred to as the
Specific criteria define the various types of sleep apnea. In general,
persons with sleep apnea will have more than five episodes an hour during
sleep when they cease breathing for ten or more seconds. Often, the
breathing will cease for more than 30 seconds and may occur up to 60 times
an hour. Most people with sleep apnea will also have snoring and daytime
Sleep apnea is associated with a number of medical conditions related to
the cardiovascular system. It is also associated with headaches, anxiety,
memory loss and poor concentration. The primary symptom is daytime
sleepiness. Of major concern is the well documented increase risk of
automobile accidents in people with sleep apnea NEJM 1999; 340:847-51 and
NEJM 1999 340:881-883. Obviously, this finding also has significant
implications for pilots/controllers and aviation safety.
Types of Sleep Apnea
Two major types of sleep apnea exist. The most common type, representing
90% of cases, is Obstructive Sleep Apnea (OSA). A second type is Central
Sleep Apnea (CSA).
OSA is primarily a mechanical phenomenon with the structures of the mouth,
tongue, neck and pharynx blocking an individual’s airway during sleep.
These soft tissues cause repeated obstruction of the airways. This
obstruction is caused both by gravity pulling tissues into the airway and
by excess tissue encroaching on and narrowing the airway. As a result, the
individual makes a respiratory effort that can be documented in the rib
cage and diaphragm when monitored in sleep studies. However, because of
the obstruction, there is restricted airflow through the mouth and nose.
Partial obstruction of the airway results in snoring. Snoring is produced
when a small amount of air passes by a partial or intermittent obstruction
in the airway. Usually, this obstruction is at the level of the oropharnyx
(tongue, soft palette and epiglottis).
After a period of apnea (not breathing) or struggling to breathe, the
individual arouses slightly, increases the tone of the muscles, unblocks
the airway and then moves air through the mouth and nose into the lungs.
This process is repeated dozens to hundreds of times during the night.
Essentially, OSA is a continuous cycle of sleep, snoring, obstruction,
nocturnal arousal and sleep. The result is very fragmented, poor quality
sleep. Significant cardiovascular side effects result from the apnea as
Central sleep apnea is a neurological phenomenon resulting from a failure
of the brain to send a signal to the muscles of the rib cage and diaphragm
to breathe. No obstruction is present in pure CSA. During monitoring,
there is no activity in the rib muscles, diaphragm or the airway.
Mixed sleep apnea is a condition with components of both OSA and CSA. All
types of sleep apnea result in a drop in the oxygen saturation of the
blood. In an effort to compensate for the reduced oxygen saturation, the
body will increase heart rate and blood pressure. This places additional
strain on the cardiovascular system during sleep, a period designed for
recovery rather than stress. Eventually, the reduced oxygen causes the
brain to send a signal to the respiratory muscles to resume breathing.
A primary risk factor for OSA is obesity, though not everyone with OSA is
obese. People with short, thick necks may have compression of the airway
when relaxed. The New England Journal of Medicine published an article on
the increased risk of OSA in football players. An increase in the Body
Mass Index of 1 (approximately 7 pounds in a six foot tall individual)
increases the risk of abnormal sleep due to disordered breathing by 30%
over 4 years.
Additional risk factors include a recessed or underdeveloped jaw. These
conditions may force the soft tissues of the neck to a more rearward
position than normal when supine and obstruct the airway. Chronic
tonsillitis and upper respiratory infections/allergies may also increase
the risk of OSA.
An association between hypertension and OSA has been documented.
Approximately half of people with hypertension are estimated to have OSA
and half of those with OSA will have hypertension. A similar relationship
exists with obesity.
The risk of sleep apnea increases with increasing age. Family history of
OSA is another risk factor. Other risk factors include abnormally
excessive tissue in the throat or nasal passages. There is some
controversy about whether nasal polyps or a deviated nasal septum will
increase the risk of OSA.
Sedative medications, drugs and alcohol increase the risk of both central
and obstructive sleep apnea.
Symptoms of Sleep Apnea
Persons who snore heavily should be evaluated for OSA. This is the primary
symptom of OSA. Additionally, sleeping partners may notice that an
affected individual may stop breathing for prolonged periods of time and
then awake with a deep breath.
The second major symptom is daytime sleepiness. Because the night time
sleep is fragmented and disturbed, daytime sleepiness is a manifestation
of the body’s attempt to recover. Daytime sleepiness is especially common
during period of relative inactivity. Sitting at a desk, reading, driving
or flying when on autopilot are high risk times for falling asleep for
people with OSA
Other associated symptoms are recent increases in weight, excessively loud
snoring (“shake the bed, wake the dead”), awakening with a fatigued
feeling despite an adequate period in bed and high blood pressure.
Adverse Medical Effects
The medical effects of sleep apnea can be significant. There are no
conclusive studies that demonstrate a direct causal relationship with
particular cardiac events. However, a growing body of literature links
moderate and severe sleep apnea with hypertension, stroke, heart attacks,
cardiac arrhythmias, congestive heart failure and death. The risk of
hypertension is increased three-fold in people with severe OSA. Treating
OSA may reduce hypertension.
Patients with OSA may also have complications following surgery. Sedatives
and narcotics used may lead to reduced muscle tone in the muscles of the
neck and pharynx during recovery. This may lead to reduced oxygen levels,
increased carbon dioxide levels, heart rhythm irregularities and
Depression and anxiety may be exacerbated by chronic fatigue due to
disturbed sleep. Additionally, OSA has been linked with memory loss and
An alarming scientific study in 1999 demonstrated a six-fold increase in
automobile accident rates in people diagnosed with OSA over those who did
not have this condition. The risk was even higher if alcohol had been
consumed on the day of the accident if the subject met the criteria for
moderate or severe sleep apnea. These risks were independent of numerous
other risk factors for automobile accidents. The study subjects were aged
30 to 70 years with a mean age of 44. Three quarters of the subjects
involved were men.
An accompanying editorial in the same journal outlines recommendations to
restrict driving in people afflicted with sleep apnea and other sleep
disorders. Additional recommendations included having physicians report
people diagnosed with sleep apnea to state motor vehicle authorities,
similar to requirements for people with seizures. Diverse groups such as
the American Thoracic Society, the Federal Highway Administration and
several states have made these recommendations. California will issue a
time-limited driver’s certificate requiring review every 3-6 months in
partially controlled sleep disorders and suspends licenses in uncontrolled
The FAA has similar concerns regarding pilots flying with sleep apnea. In
solo operations, micro-sleeps or repeated “dozing off” may result in
mishaps, deviations from ATC instructions or violations of Federal
Aviation Regulations. In commercial operations requiring crew
coordination, a pilot with uncontrollable fatigue presents an unacceptable
risk to flight safety. Memory loss and impaired concentration still
compromise safety, even in the absence of in-flight sleep. Policies on
medical certification are discussed below.
Sleep apnea must be distinguished from simple snoring and other causes of
sleep disturbances. These causes include insufficient sleep, circadian
rhythm disturbance, narcolepsy and periodic limb movements/restless legs
syndrome. Conditions that may also present with excess daytime sleepiness
include depression, anxiety, and use of medications and abuse of
stimulants, sedatives and alcohol. [See International Classification of
Sleep Disorders for a complete listing.]
A simple questionnaire may help identify people at risk for sleep apnea
who should be formally evaluated. The Berlin questionnaire successfully
predicted those people who had the most significant abnormal findings on
sleep testing. Questions about weight change, snoring loudness, snoring
frequency, breathing pauses, daytime fatigue, hypertension and falling
asleep when driving are used in the Berlin survey. Several alternate
surveys exist addressing OSA risk. One in common use is the Epworth
Sleepiness Scale, which develops a score based on a person’s self-rating
of likeliness to fall asleep in eight situations.
Individuals at high risk for sleep apnea or those who have symptoms such
as daytime sleepiness, multiple automobile accidents and loud snoring
should be referred for formal sleep testing. Additionally, people with
short, thick necks or recessed jaws may benefit from testing.
Sleep Testing - Polysomnogram
The diagnosis of sleep apnea is confirmed by testing known as nocturnal
polysomnography. The polysomnogram (PSG) measures a number of
physiological factors when an individual is sleeping. Factors include
brain wave activity (electroencephalogram), eye movement, airflow, chest
movement, leg movement, heart rhythms (electrocardiogram) and oxygen
saturation of the blood. Video monitoring is sometimes conducted during
Two measures characterize the severity of abnormal breathing during the
PSG. The Respiratory Disturbance Index (RDI), used in home/portable
monitors, is a measure of the number of breathing disturbances during one
hour of monitoring. The Apnea – Hypopnea Index (AHI) is used during the
more formalized PSG testing. It describes the number of time breathing
ceases (apnea) or is sub-optimal (hypopnea) per hour of monitoring. The
RDI and AHI are roughly equivalent.
A RDI/AHI of less than 5 usually is interpreted as normal. “Mild” sleep
apnea usually is associated with a RDI/AHI of 10-20. Higher RDI/AHIs may
be characterized as “moderate” (20-30) or “severe” sleep apnea (greater
than 30). These RDI/AHI figures are not rigid. Other factors, such as
measured daytime sleepiness and oxygen saturation during sleep influence
the classification of mild, moderate and severe sleep apnea.
Oxygen saturation of the arterial blood should remain above 90% in the
normal individual when sleeping. The PSG measures both the mean and the
minimum oxygen saturation during the study. Lower oxygen saturations raise
concern about the severity of the sleep apnea.
Frequently, polysomnography may be divided into two phases during the same
study. The first phase measures all parameters in the natural state of
sleep. The second phase measures the same factors when the individual is
being treated for the sleep apnea (see below) to see if there improvement
with treatment. This type of PSG is known as a “split sleep study” or a
Sleep Testing - Maintenance of Wakefulness / Multiple Sleep Latency
The Maintenance of Wakefulness Test (MWT) and the Multiple Sleep Latency
Test (MSLT) are different measures of daytime sleepiness/alertness. For a
full description, see the American Sleep Disorders Association (now the
American Academy of Sleep Medicine) report. Stimulants and medications may
affect the quality and accuracy of each study.
Both studies are administered in a darkened quiet room in a reclined
position. Each involves a series of four or five 20-minute periods in the
room with 2-hour intervals between the periods where the subject is
instructed to stay awake. The five cycle MSLT is used to evaluate possible
narcolepsy while the four-cycle studies may be used to evaluate other
sleep disorders. Ideally the studies are administered following a PSG. The
ability to remain awake during this testing may be improved by sleeping in
a familiar environment the night prior to the study, if there is no sleep
During the MSLT, an individual is instructed to fall asleep during the
20-minute nap period. The MSLT measures the time it takes an individual to
fall asleep. A normal individual will usually require over 15 minutes
before falling asleep (latency) as measured by an EEG. Mild alertness
impairment may be present if the sleep latency period is between 10-15
minutes, although normal individuals may have occasional periods of
reduced sleep latency. Latency periods of 5-10 minutes may indicate
moderate impairment and shorter period may be characterized as severe.
In contrast to the MSLT, an individual undergoing a MWT is instructed to
stay awake during the period in the dark, quiet room. The expected result
in a person without a sleep disorder is to remain awake during each of the
four 20-minute periods and during the 2-hour intervals when walking or
participating in normal activities. The MWT evaluates daytime alertness
and is more relevant for medical certification authorities. The FAA
prefers the MWT to the MSLT in evaluating individuals following treatment
for sleep apnea.
Some sleep clinics routinely perform drug testing in conjunction with PSGs,
MWTs and MSLTs to document that neither sleeping medications nor
stimulants to stay awake have been used to influence the results of
Obstructive Sleep Apnea Treatments
The goal of treatment of OSA is maintenance of an open, unobstructed
airway during sleep. Both surgical and non-surgical treatments are
available. Several treatments are acceptable to the FAA in
pilots/controllers diagnosed with OSA who seek reinstatement of medical
certification. However, some treatments offered for correction are not
acceptable to the FAA, primarily because their effectiveness cannot be
The most widely used and effective treatment is Continuous Positive Airway
Pressure (CPAP). This treatment involves wearing a mask over the nose and
strapped around the head. The mask is connected to a tube that has a fan
blowing air continuously thorough the nostrils. The air pressure, which
can be adjusted as necessary, keeps the soft tissues from collapsing the
airway and allows regular, unobstructed breathing through the night.
Variants of CPAP include nasal CPAP (nCPAP) which uses nasal “pillows” in
the nostrils instead of a mask, and BiPAP which has varying air pressures
in different phases of respiration to enhance comfort. A variety of masks
may be used to adjust to an individual's facial structures.
Adverse effects of CPAP may include a runny nose, nasal congestion, skin
irritation from the mask and irritation / intolerance of the mask. Some
people have claustrophobia to an extent that they cannot tolerate the
nasal mask. Overall, non-compliance is the most significant issue in
treating OSA non-surgically with CPAP.
CPAP requires a shoebox-sized machine with the fan and pressure adjusting
mechanism, the associated tubing and mask and an electrical supply. Pilots
who participate in transoceanic flights with rest periods may find it very
challenging to set up and use a CPAP device on the aircraft, although once
on the ground, treatment is usually much easier.
CPAP and its variants are the only non-surgical treatments for OSA
authorized by the FAA for pilots and controllers.
Oral appliances that bring the jaw forward or prevent the tongue from
relaxing back and obstructing the airway are also use to treat OSA. These
devices are not as effective as CPAP or surgery in relieving OSA, but may
reduce snoring. These devices may be used to complement CPAP and surgical
treatments for OSA. They may also be used in persons not tolerating CPAP
or declining surgery.
Weight reduction is another non-surgical approach to OSA. Unfortunately,
the long-term success of weight loss programs is low. Even with gastric
by-pass surgical procedures, weight loss does not result in any immediate
improvement in OSA or daytime sleepiness. The FAA does not recognize
weight loss alone as a sufficient treatment for medical certification.
Oxygen supplementation may be used to complement CPAP, but is not adequate
as sole therapy because it does not relieve the obstruction.
Sleep posture modification has also been attempted. Because airway
obstruction may be due to gravity pulling soft tissues of the neck against
the airway when lying on one’s back, sleeping on the side may relieve
snoring and airway obstructions. One method of sleep posture adjustment
has been to wear a sleep-shirt with tennis balls sewn into the back. When
feeling the pressure of the tennis balls, an individual wearing such a
shirt will tend to roll from lying on the back to on the side. This method
is not an FAA-approved treatment for medical certification purposes.
If conservative measures such as CPAP are ineffective or not tolerated,
surgical treatment options for OSA exist.
The primary surgical correction for OSA caused by excessive or redundant
tissues in the pharynx is termed uvulopalatopharyngoplasty (UPPP). The
tonsils, if present, are removed as are the uvula and rear portion of the
palate. The surgery may reduce the RDI/AHI by approximately 50%. It is
very effective in reducing snoring. The UPPP may require several days of
hospitalization. The recovery period may extend from several weeks to two
An alternate to the UPPP is the laser-assisted uvulopalatoplasty (LAUP),
which can be performed in the office setting using local anesthesia. The
procedure involves using a laser to resect the uvula and soft palate. The
LAUP is also effective in relieving snoring.
A third procedure used in people who have a recessed jaw is termed
mandibular advancement. It is the most invasive and involves a prolonged
recovery period with the upper and lower jaws wired together.
Another surgical procedure to treat OSA, albeit indirectly, is gastric
(stomach) surgery in massively obese individual in an effort to
drastically reduce weight. Hopefully, with reduction of weight over time,
the excessive tissues compressing the airways will be reduced. This
procedure does not have an immediate effect on improving OSA, even if it
is successful. When determining medical qualification, the FAA does not
consider this treatment, by itself, to be typically adequate in pilots and
controllers with OSA.
FAA Policies and Certification Issues
The primary concern of the FAA with sleep disorders relates to alertness
when on duty in the cockpit or tower cab. Secondary concerns involve the
complications and associated symptoms of sleep apnea, such as memory and
concentration impairment, heart arrhythmias and other conditions that may
cause subtle or sudden incapacitation when flying or controlling. Under
current policy as outlined in the FAA Guide for Aviation Medical
Examiners, any degree of sleep apnea is disqualifying for all classes of
medical certification. AMEs do not have the authority to grant an initial
waiver for medical certification for pilots with sleep apnea.
Pilots diagnosed with sleep apnea may be granted medical certification
under the Special Issuance provisions of 14 CFR 67.401. Controllers may
get Special Consideration from the Regional Flight Surgeon. The FAA
Protocol for Evaluation of Sleep Apnea outlines procedures for testing in
support of recertification requests. The essential elements are a
split-study or second PSG following treatment, a normal MWT or MSLT and
documentation that the pilot/controller no longer experiences any daytime
sleepiness. The individual must tolerate and comply with the treatment for
OSA. The FAA usually requests an annual physician current status report in
individuals requiring treatment as a requirement to maintain Special
Issuance medical certification.
Sleep apnea is a relatively common medical condition with potentially
serious medical and occupational consequences. For people performing
safety sensitive duties, the daytime sleepiness associated with sleep
apnea is the most immediately hazardous consequence. Persons with risk
factors for or symptoms of sleep apnea should be evaluated with
polysomnography. Several treatments are available in individuals for whom
the diagnosis is confirmed. The success of the treatment should be
evaluated both using repeat PSG and MWT/MSLT. With successful treatment of
sleep apnea, FAA medical certification is likely. Treatment will result in
improvement of subjective symptoms and health complications of sleep apnea.