Developed in collaboration with CASA Medical.
Obstructive sleep apnoea (OSA) is a common sleep disorder caused by repetitive collapse of the upper airway during sleep. OSA has a potential effect on performance including reduced alertness, impaired short-term memory and learning, impaired judgement and reasoning, slowed psychomotor response times and sleep deprivation. It is associated with other significant health problems such as hypertension, cardiovascular disease, stroke, congestive heart failure, atrial fibrillation and metabolic syndrome.
Risk factors associated with OSA include:
- genetics
- decreased muscle tone- age, depressant drugs, muscle disorders, brain injury
- obesity
- alcohol and smoking
- structural factors related to the anatomy of the face and airways
- asthma
- chronic nasal congestion
- male gender
The clinical diagnosis of OSA is confirmed if the number of obstructive events is more than 5 events per hour of sleep. Many people also have symptoms including headache, daytime sleepiness, loud snoring, witnessed breathing interruptions, or awakenings due to gasping or choking. Moderate and severe sleep apnoea is associated with accidents and other serious health problems.
Continuous positive airway pressure (CPAP)/ Automatic Positive Airway Pressure (APAP) the main treatment for OSA. CPAP/APAP machines are compact, highly portable, and quiet. When CPAP/APAP is used, it should be utilised for at least > 5 hours per night and for 80% of sleep night and must be used must be used in the sleep period immediately prior to aviation duties. If the CPAP/APAP machine used does not have a data download function (most modern ones do), additional annual specialist reports, sleep studies or other tests may be required.
CPAP/ APAP data must be sent to CAA 4 weeks after starting treatment, and usually every three months after that.
Effective control of sleep apnoea reduces the risk of cardiovascular disease, stroke, type 2 diabetes, hypertension and congestive heart failure which are also flight safety relevant conditions.
Pilot and controller information
- If pilots or controllers suspect they might have or have been diagnosed obstructive sleep apnoea they should obtain a ME review.
- Pilots and controllers must stand down from aviation duties if they experience any problems with their treatment or experience a recurrence of their symptoms, eg daytime sleepiness and consult their ME.
Aeromedical implications
Effect of aviation on the condition
- Aviation duties can worsen quality of sleep:
- Irregular work and sleep hours, circadian shifts
- Inconsistent sleeping environments
- Scheduled sleep periods during long haul flight at cabin altitude with additional mild hypoxia
- Lifestyle factors in pilots and controllers
- Combination of these factors contribute to fatigue
- Difficulty carrying Continuous positive airway pressure (CPAP)/ Automatic Positive Airway Pressure (APAP) machine when operating away from home
Effect of the condition on aviation
- Overt incapacitation
- Hypersomnolence
- Unplanned falling asleep
- Microsleep
- Subtle incapacitation
- Untreated OSA can significantly impact flight safety due to its effects on cognition and psychomotor performance including:
- Excessive daytime sleepiness
- impaired alertness and reaction times
- Impairment of cognition, including
- impaired memory, attention, and decision-making abilities
- Impaired psychomotor performance due decreased co-ordination and motor skills resulting from poor sleep +/- sleep deprivation
- Mood disturbance
- Headache
Approach to medical certification
Based on the condition
- Identify the severity of OSA
- Identify common comorbidities. Factors to consider include:
- Obesity (BMI > 35)
- Increased neck circumference (more than 42cm for men and more than 40cm for women)
- Congestive heart failure
- Atrial fibrillation
- Treatment refractory hypertension
- Type 2 diabetes
- Nocturnal dysrhythmias
- Stroke
- Pulmonary hypertension
- Pre-operative for bariatric surgery
- Exclude other sleep disorders e.g. central sleep apnoea, narcolepsy, idiopathic hypersomnolence
Based on treatment
- Response to other treatments mandibular advancement splint, positioning devices, surgical treatment).
- Response to lifestyle modifications
- Weight loss, positional therapy, avoidance of alcohol and sedatives
- Response to positive airway pressure (PAP) therapy
- CPAP at fixed or automatic variable pressure or bilevel PAP
- Evidence of effectiveness of mandibular advancement splint or positioning devices
- Response to surgical options
- Uvulopalatopharyngoplasty (UPPP), maxillomandibular advancement (MMA)
Demonstrated stability
- Symptom-free on treatment.
- Downloaded CPAP/APAP data demonstrating control and compliance with therapy.
- Duration: often defined as using CPAP > 5 hours per night on at least 80% of nights and must be used in the sleep period immediately prior to aviation duties.
- Correct use: Proper application and maintenance - minimal mask interface leaks.
- Repeat sleep study on treatment if clinically indicated –see below.
Risk assessment protocol - information required
New cases
- A report from a Sleep Physician with respect and diagnostic testing for OSA should be performed in conjunction with a comprehensive sleep evaluation and adequate follow-up
- Thorough sleep history and physical examination that includes the respiratory, cardiovascular and neurologic symptoms
- Sleep physician referral for potential OSA is required when:
- symptoms of OSA are present
- STOPBANG score ≥ 3
- Sleep physician referral and investigation for OSA should be considered when the following risk factors are present:
- Sleep physician report should include:
- Confirmation or exclusion of the diagnosis of OSA and severity
- Results of any sleep studies
- Management
- Treatment selected, tolerability and compliance.
- Objective measure of sleep apnoea control on treatment – CPAP/APAP data download (if applicable).
- Cardiovascular disease risk assessment
- Repeat sleep specialist review with unexplained CPAP/APAP data.
- A repeat sleep specialist review, including sleep study, will be required where treatments lack objective data, e.g. mandibular splints, pharyngeal surgery
- A repeat sleep specialist review is required if symptoms are recurrent or persistent. Persistence of excessive daytime sleepiness is common after treatment.
- Follow-up plan and monitoring of stability and compliance
- Additional specialist reports may be required for other co-morbid conditions e.g. cardiology. Refer to the relevant CPG for certification guidelines.
Renewal
- A report from a Sleep Physician with respect to:
- Clinical status (alertness)
- Progress
- Review of CPAP/APAP data download (if applicable) - including usage statistics and objective measure of sleep apnoea control - Apnoea Hypopnea Index (AHI)
- Investigations conducted
- A repeat sleep study will be required if there has been weight gain of 10%, an occurrence or change in cardiovascular disease, or with unexplained CPAP data.
- A repeat sleep study if there has been a weight loss of 10% or more (e.g. following bariatric surgery or weight loss programme/medication) to determine is CPAP treatment is still required.
- A repeat sleep study will be required where treatments lack objective data, e.g. mandibular splints, pharyngeal surgery.
- A repeat sleep specialist assessment is required when there is persistence of excessive daytime sleepiness which is common in early phase of treatment.
- Management
- Treatment selected, tolerability and compliance
- Follow-up plan and monitoring.
ME aeromedical decision guide
If all criteria in the table below for an applicant with treated OSA are met, the applicant meets the acceptable criteria for certification by the ME. Evidence supporting the ME’s decision (for example reports and results) must be sent to CAA.
An AMC referral to CAA NZ AvMed is required if pilot’s or controller’s condition does not meet all the above criteria and they consent to their condition being considered under flexibility to the CAR 67 rules.
ME letters
OSA medical certificate letter [DOCX 23 KB]
