Obstructive sleep apnoea Flashcards
When should I suspect a diagnosis of obstructive sleep apnoea syndrome?
Suspect a diagnosis of obstructive sleep apnoea syndrome (OSAS) in an adult with:
- Excessive daytime sleepiness, snoring, and fatigue.
- Witnessed breathing pauses (apnoeas), gasping, or choking while sleeping.
- Unrefreshing sleep, impaired concentration.
Consider a diagnosis of OSAS in an adult with:
- Unexplained morning headache (typically resolves within hours of waking).
- Frequent nocturnal awakenings.
Unexplained nocturia.
- Nocturnal gastro-oesophageal reflux disease (GORD).
- Associated conditions such as obesity, depression, hypertension, or stroke disease.
How should I assess a person with suspected obstructive sleep apnoea syndrome?
If a diagnosis of obstructive sleep apnoea syndrome (OSAS) is suspected:
Ask about:
The duration and severity of symptoms, such as snoring, gasping during sleep (apnoeas), and excessive daytime sleepiness including during high-risk activities such as driving.
A collateral history from a partner regarding snoring habits, apnoeas, and choking episodes during sleep is helpful, where possible.
The impact of symptoms on quality of life including relationships, mood, sleep, and social activities. In children, the impact of symptoms on school performance, concentration, behaviour, and growth.
Any impact of symptoms on driving and work-related safety, including distances driven; any episodes of driving while sleepy; any road traffic collisions or near-misses that could be due to sleepiness, fatigue, or inattention.
- Any risk factors for OSAS.
- Any associated conditions.
- Any clinical features suggesting an alternative diagnosis.
Examine the person for:
- Jaw abnormalities such as micrognathia (small jaw) or retrognathia (abnormal jaw positioning with mandible set back from the maxilla).
- Signs of nasopharyngeal obstruction such as mouth breathing or nasal speech (for example due to adenotonsillar enlargement, nasal polyps, or a deviated nasal septum).
- Signs of chronic obstructive pulmonary disease (COPD), respiratory failure, or pulmonary hypertension (may influence the urgency of referral). See the section on Referral for more information.
- Blood pressure, body mass index (BMI), and neck circumference (collar size) in adults.
Consider using a screening questionnaire to assess the extent and severity of symptoms.
Options include:
- STOP-Bang questionnaire.
An eight-item tool that assesses snoring, sleepiness, apnoeas, hypertension, obesity, neck circumference, age, and sex.
- Epworth sleepiness scale.
A self-administered eight-item tool assesses the likelihood of daytime sleepiness in a variety of common situations.
Note: Do not use the Epworth Sleepiness Scale alone to determine if referral is needed, because not all people with OSAS have excessive sleepiness.
Differential diagnosis for OSA - what else could it be?
Other conditions that may present similarly to obstructive sleep apnoea syndrome (OSAS) include:
Snoring
Simple snoring — noisy breathing caused by turbulent airflow through the upper airway, for example due to obesity, nasal obstruction, or upper respiratory tract infection.
Daytime sleepiness
Sleep disturbance or deprivation — for example due to pain, anxiety, or employment with shift work. See the CKS topic on Sleep disorders - shift work and jet lag for more information.
Other sleep disorders — such as insomnia, periodic limb movements (restless legs syndrome), narcolepsy, and parasomnias (including night terrors). See the CKS topics on Insomnia and Restless legs syndrome for more information.
Neurological or neuromuscular disorders — such as previous head injury, motor neurone disease, Parkinson’s disease, and myotonic dystrophy. See the CKS topic on Parkinson’s disease for more information.
Hypothyroidism. See the CKS topic on Hypothyroidism for more information.
Depression. See the CKS topics on Depression and Depression in children for more information.
Drugs — such as benzodiazepines, beta-blockers, anti-epileptic drugs, and selective serotonin reuptake inhibitors (SSRIs).
Nocturnal choking or gasping
Gastro-oesophageal reflux disease (GORD). See the CKS topics on Dyspepsia - proven GORD and GORD in children for more information.
Nocturnal asthma. See the CKS topic on Asthma for more information.
Heart failure. See the CKS topic on Heart failure - chronic for more information.
Panic attacks. See the CKS topics on Generalized anxiety disorder and Post-traumatic stress disorder for more information.
Behavioural problems, reduced concentration (children)
Attention deficit hyperactivity disorder (ADHD). See the CKS topic on Attention deficit hyperactivity disorder for more information.
When should I refer a person with suspected obstructive sleep apnoea syndrome?
Arrange urgent referral to a sleep clinic (ideally to be seen within 4 weeks) for further investigation and management if an adult:
- Has excessive sleepiness impacting on their role as a professional driver or other safety-critical worker (for example pilot, bus or lorry driver, or operator of dangerous machinery). Advise the person not to drive until they have been assessed by a specialist. See the section on Advice on driving for more information.
- Has a comorbid condition such as chronic obstructive pulmonary disease (COPD), poorly controlled arrhythmia, nocturnal angina, heart failure, treatment-resistant hypertension, pulmonary hypertension, or respiratory failure. See the CKS topics on Chronic obstructive pulmonary disease and Heart failure - chronic for more information.
- Is pregnant.
- Is undergoing pre-operative assessment for major surgery.
- Has non-arteritic anterior ischaemic optic neuropathy.
Arrange routine referral to a sleep clinic for further investigation and management if an adult:
- Has suspected moderate or severe OSAS, or suspected mild OSAS that is impacting on the person’s quality of life.
Sleep studies
- Polysomnography (PSG) or a limited sleep study is often used to measure sleep-wake state and apnoea/hypopnoea episodes to confirm the diagnosis of obstructive sleep apnoea syndrome (OSAS) in adults and children
A limited sleep study can be set up at home, but more complex studies may require an overnight stay in a specialist sleep laboratory.
The severity of OSAS is based on the severity of symptoms and the number of apnoea/hypopnoea episodes per hour (the apnoea-hypopnoea index [AHI]). AHI does not correlate well with severity of clinical symptoms.
The diagnosis of OSAS in adults requires at least five episodes of apnoea, hypopnoea, or both events lasting a minimum of 10 seconds per hour of sleep.
Mild: AHI 5–14 per hour.
Moderate: AHI 15–30 per hour.
Severe: AHI more than 30 per hour.
If access to home respiratory polygraphy is limited, NICE recommend that consideration could be given to the use of home oximetry for people with suspected OSAS. [NICE, 2021].
The oxygen desaturation index (ODI) may be a more reliable predictor of adverse cardiovascular outcomes than AHI. Overnight pulse oximetry may be used as a screening tool for some people to identify nocturnal desaturation events
Specialist treatments for confirmed OSASyndrome
CPAP therapy may be offered to all people with symptomatic OSAS, and is the first-line treatment for moderate-to-severe OSAS [NICE, 2008; Semelka, 2016; Stradling, 2016; Francis, 2020; Gottlieb, 2020].
Airway pressure may be delivered through a nasal or face mask for airflow delivery at night, and the pressure acts to splint the upper airways to prevent collapse during inspiration.
Poor adherence to CPAP is common due to an ill-fitting mask, pressure intolerance, or upper airway symptoms such as nasal dryness or bleeding, or throat irritation. Adherence rates may improve with early patient education and support.
There is evidence that CPAP therapy improves daytime sleepiness, fatigue, and quality of life in studies. In addition, it may lower blood pressure, especially in people with resistant hypertension, but there is no confirmed significant benefit on rates of cardiovascular or stroke disease.
Treatment is needed long term unless there is associated weight loss sufficient to cause disease remission.
Intra-oral mandibular advancement devices may be appropriate for people who snore or have mild OSAS with normal daytime alertness. They can also be used as an alternative for people unable to tolerate CPAP, who do not respond to CPAP, or who prefer treatment with an intra-oral device [Ramar, 2015; Semelka, 2016; Stradling, 2016; Dieltjens, 2019; Francis, 2020; Gottlieb, 2020].
Mandibular advancement devices consist of plates made to fit the upper and lower teeth to be worn during sleep, and vary in complexity and cost. They provide forward advancement of the mandible and attached tongue during sleep, to maintain an open upper airway and reduce airway collapsibility. Custom-made titratable appliances made by a dental specialist or maxillofacial surgeon may be most effective.
A meta-analysis of 34 randomized controlled trials (n = 1301) found evidence of clinical benefit and reduced apnoea-hypopnoea index (AHI) measurements [Ramar, 2015].
Upper airways surgery such as tonsillectomy may be occasionally considered if there is evidence of nasopharyngeal obstruction causing symptoms. Very rarely alternative upper airway surgery to reduce the volume or configuration of oropharyngeal soft tissues or bony structures may be recommended if other treatments have failed [Greenstone, 2014; Stradling, 2016; Randerath, 2018].
How should I manage a person with confirmed obstructive sleep apnoea syndrome?
If a person has a confirmed diagnosis of obstructive sleep apnoea syndrome (OSAS) following specialist assessment:
Provide advice on sources of information and support:
The Sleep Apnoea Trust Association (website available at www.sleep-apnoea-trust.org) is a charity for people with sleep apnoea, their partners and families, which provides a variety of information leaflets on OSAS, continuous positive airway pressure (CPAP) therapy, weight loss, and driving.
The British Lung Foundation (BLF) is a national charity supporting people with lung conditions, which has patient information on OSAS, diagnosis, treatment, driving, and travel, as well as information about OSAS in children.
The NHS information leaflet Sleep apnoea.
Offer management of any modifiable risk factors, and advise on lifestyle measures, such as:
Weight loss including diet, exercise, and/or weight loss surgery, if appropriate. See the CKS topic on Obesity for more information.
Stopping smoking. See the CKS topic on Smoking cessation for more information.
Reducing alcohol intake. See the CKS topic on Alcohol - problem drinking for more information.
Avoiding sleeping on their back and to sleep on their side, where possible. The use of positioning pillows, devices, and alarms may be helpful.
Encourage adherence to specialist treatment, such as CPAP therapy or intra-oral devices worn at night.
Monitor for and manage any associated conditions including cardiometabolic disease and depression.
Provide advice on driving regulations and advise the person to check with their insurer whether they are still insured to drive under their current policy. See the section on Advice on driving for more information.
What advice should I give about driving?
Advise a person who drives and has excessive sleepiness (Group 1 car and motorcycle):
Due to suspected obstructive sleep apnoea syndrome (OSAS) or confirmed mild OSAS:
They must not drive.
Driving may resume only after satisfactory symptom control.
If symptom control cannot be achieved in 3 months, the person must notify the Driving and Vehicle Licensing Agency (DVLA).
Due to confirmed moderate or severe OSAS:
They must not drive and must notify the DVLA. The gov.uk publication Excessive sleepiness and driving has information on how to notify the DVLA.
Subsequent licensing will require control of the condition; improved sleepiness; treatment adherence. Note: the DVLA will need medical confirmation, and the driver must confirm review to be undertaken every 3 years at the minimum.
The DVLA patient leaflet Tiredness can kill. Sleepiness and tiredness may be helpful for Group 1 drivers concerned about excessive sleepiness.
Advise a person who drives and has excessive sleepiness (Group 2 bus and lorry):
Due to suspected OSAS or confirmed mild OSAS:
They must not drive.
Driving may resume only after satisfactory symptom control.
If symptom control cannot be achieved in 3 months, the person must notify the DVLA.
Due to confirmed moderate or severe OSAS:
They must not drive and must notify the DVLA. The gov.uk publication Excessive sleepiness and driving has information on how to notify the DVLA.
Subsequent licensing will require control of the condition; improved sleepiness; treatment adherence. Note: the DVLA will need medical confirmation, and the driver must confirm review to be undertaken annually at the minimum.
The DVLA patient leaflet Tiredness can kill. Sleepiness and tiredness may be helpful for Group 2 drivers concerned about excessive sleepiness.
Advise a person that they may continue to drive and do not need to notify the DVLA if they have suspected or confirmed OSAS but do not have excessive sleepiness which is having, or is likely to have, an adverse effect on driving.
