People living with obstructive sleep apnoea (OSA) experience repetitive episodes of partial or complete closure of the upper-airway during sleep.
Abnormal relaxation of respiratory muscles causes sufferers to snore and to sometimes wake up gasping or choking.
While many people with OSA don't realise they have disturbed sleep, the condition causes excessive daytime fatigue and poor concentration.
As well as aviation, motor vehicle and industrial accidents, OSA increases the risk of:
- obesity
- high blood pressure
- stroke
- heart attack
- type 2 diabetes
- depression
- impotence
- mood disorders.
When the respiratory muscles relax during sleep in OSA, soft tissues in the back of the throat collapse and block the upper airway. This leads to partial reductions (hypopneas) and complete pauses (apnoeas) in breathing lasting 10 seconds or more.
Sleep clinicians measure the severity of OSA using the Apnoea Hypopnea Index (AHI) and oxygen desaturation levels. The AHI is the number of apnoeas or hypopnoeas recorded during the study per hour of sleep.
The number represents events per hour. Based on the AHI, the severity of OSA has the following classifications:
- none/minimal: less than 5 AHI per hour
- mild: more than 5 but less than 15 AHI per hour
- moderate: between 15 and 30 AHI per hour
- severe: more than 30 AHI per hour.
If you suspect that you have OSA or you have symptoms of OSA, you should see your general practitioner (GP).
You may receive a referral for a sleep study so medical professionals can look for OSA and other sleep disorders. These studies help them to find suitable treatment for your condition.
Effects of flying on OSA
OSA sufferers may find their condition worsens during a flight because of:
- irregular work and sleep hours
- difficulty carrying continuous positive airway pressure (CPAP) equipment when operating away from home
- lifestyle factors leading to increased BMI.
The effect of the condition on aviation
Those who are living with OSA and are flying can experience either overt or subtle incapacitation. They include:
Overt incapacitation
- Hypersomnolence
- Increased risk of cardiovascular disease, cerebrovascular disease, insulin resistance, hypertension and congestive heart failure
Subtle incapacitation
- Reduced attention and concentration
- Degraded cognition
Implications for pilots and controllers
If your doctor diagnoses you with OSA, you must ground yourself and get a Designated Aviation Medical Examiner (DAME) review.
Moderate and severe sleep apnoea can potentially cause accidents and health problems.
Fortunately, modern CPAP machines are portable. If the CPAP machine you use does not have a data download function, you may need to provide us with:
- additional annual specialist reports
- sleep studies
- other tests.
Other advice includes:
- you are not to fly if you experience any problems with your treatment or experience a recurrence of your symptoms
- if you are using CPAP, you should use it for at least 5 hours per night and for 6 nights per week. You must use it during the sleep period just prior to flight
- effective control reduces the risk of cardiovascular disease, cerebrovascular disease, insulin resistance, hypertension and congestive heart failure
- we may be able to issue Class 1, 2 and 3 certification if you can show evidence your condition is being satisfactory controlled
- once you can demonstrate effective OSA management and stability you may only need to show CASA your CPAP download to satisfy review requirements
- in case of other treatment modalities, CASA will need you to provide other evidence of control of this condition
- we require annual review of Class 1 and 3 sufferers of OSA.
Approach to medical certification
More likely to gain certification
You are more likely to gain certification if you can show CASA objective measures which demonstrate your OSA is under control.
Less likely to gain certification
You are less likely to gain certification if:
- you experience symptomatic OSA
- you show inadequate compliance with treatment regimes
- you have poor AHI control.
You are unique
Every case of OSA is different. How your OSA affects you will depend on a range of circumstances. We make aeromedical decisions on a case-by-case basis. We base a particular assessment decision on the individual circumstances of the applicant under consideration.