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AdelBachour
Hanna-RiikkaKreivi

Sleep Apnoea in the Adult

Essentials

  • Increasing levels of obesity have raised the prevalence of obstructive sleep apnoea. Sleep apnoea is most common among middle-aged people.
  • The diagnosis is confirmed by sleep apnoea investigations (home sleep apnoea testing [HSAT], also known as limited night polygraphy, or polysomnography [PSG], also known as sleep polygraphy).
  • Untreated sleep apnoea increases sympathetic nervous activity, the risk of cardiovascular disease, traffic or other accidents, use of health care services and premature death.
  • Weight reduction and weight management constitute the first and most important treatment measures for every overweight patient with obstructive sleep apnoea. In mild sleep apnoea, weight reduction may be sufficient treatment.
  • The first-line treatment for mild or moderately severe sleep apnoea is a continuous positive airway pressure (CPAP) device.
  • Mandibular advancement devices can be used to treat particularly mild or moderately severe sleep apnoea in patients with normal weight or who are overweight (BMI 25-35 kg/m2 ) and patients in whom CPAP treatment was unsuccessful.
  • Patients with sleep apnoea are usually examined in the primary health care, but CPAP treatment is still started in specialized care. Treatment with mandibular advancement devices is provided in oral health care according to local policies and care pathways.

Definitions

Types of sleep apnoea

  • Apnoea: a pause of more than 10 seconds in breathing during sleep
  • Hypopnoea: reduction in respiratory airflow by more than 30% for more than 10 seconds accompanied with a decrease in oxygen saturation by 3% or with arousal from sleep
  • Obstructive apnoea/hypopnoea: apnoea/hypopnoea caused by obstruction of the upper respiratory tract during sleep. Respiratory movements continue during this type of apnoea/hypopnoea.
  • Central apnoea/hypopnoea: apnoea/hypopnoea caused by a disturbance of central respiratory control. No respiratory movements take place during this type of apnoea/hypopnoea.
  • Mixed apnoea: a combination of the above

Indices describing sleep apnoea

  • AI = apnoea index: number of apnoea episodes per hour of sleep
  • AHI = apnoea/hypopnoea index: total number of apnoea and hypopnoea episodes per hour of sleep. AHI < 5 is considered as normal.
    • Obstructive sleep apnoea: recurring episodes of apnoea or hypopnoea during sleep. The diagnosis and the assessment of need for treatment are based on patient history, clinical examination and the results of the sleep study. Usually, AHI 5 per hour and clinical symptoms of sleep apnoea are required.
  • RDI = respiratory disturbance index: similar to AHI, but including also the so-called respiratory effort-related arousals (RERA)
  • REI = respiratory event index: like AHI but used when the sleep investigation has not been performed with polysomnography
  • ODI3 or ODI4 = oxygen desaturation index: number of episodes of oxygen saturation (SaO2) reduction by 3% or by 4% per hour during apnoea/hypopnoea

Background

  • When a person falls asleep, the muscles supporting the upper airway relax. In a structurally narrow upper airway, muscle relaxation during sleep may restrict or completely prevent air flow. Upper airway obstruction will lead to recurrent obstructive pauses in breathing, i.e. apnoea or hypopnoea episodes usually requiring arousal and resumed muscle tone to end.
  • Obstructive sleep apnoea means recurrent pauses in breathing (apnoea) or reduction in respiratory airflow (hypopnoea) of at least 10 seconds caused by obstruction of the upper airway during sleep. Sleep apnoea with symptoms is called obstructive sleep apnoea syndrome.
  • The prevalence of sleep apnoea varies considerably depending on how it is defined. It has been estimated that 17% of middle-aged men and 9% of middle-aged women have moderately severe to severe obstructive sleep apnoea. In Finnish materials, the prevalence of sleep apnoea has been shown to be 3.7-4.2%.
  • Central sleep apnoea syndrome is rare and is usually associated with central nervous system disorders or heart or renal failure (Cheyne-Stokes respiration).
  • People with sleep apnoea often have several comorbidities with the same risk factors, such as being overweight, but some associated diseases are due to sleep-disordered breathing.
  • Recently, patients with sleep apnoea have been classified by phenotype into three groups based on whether they have symptoms, daytime fatigue or sleep problems. Four groups have been distinguished in classification by endotype: mild or severe upper airway collapsibility, ventilatory control instability and low respiratory arousal threshold.
  • The roles of phenotype and endotype in the treatment of sleep apnoea are not clear yet.

Symptoms

  • Loud intermittent snoring
  • Episodes of apnoea during sleep
  • Awakening with a feeling of suffocation
  • Dry mouth, drooling in sleep
  • Insomnia
  • Nocturia
  • Nocturnal sweating, disturbed sleep at night
  • Nocturnal arrhythmias, nocturnal attacks of chest pain
  • Increased daytime fatigue, unintended lapses into sleep
  • Morning headache
  • Mood disorders, irritability and rashness, impaired memory and concentration, impotence
  • Cough
  • Heartburn

Findings

  • 50-70% of patients are overweight
  • Narrow pharynx; slack, low-reaching soft palate; swollen, large uvula that reaches the tongue; large tonsils; narrow nose; small or backward-sloping lower jaw; large tongue; short and thick neck
  • Elevated blood pressure

Diagnosis

  • The diagnosis of sleep apnoea is based on patient history, clinical examination and polysomnography or night polygraphy findings.

Investigations

  • Patient history
    • Signs and symptoms
    • The degree of daytime sleepiness can be assessed with the Epworth Sleepiness Scale (ESS) http://epworthsleepinessscale.com/about-the-ess/.
    • Occupation, professional driver's licence, driving licence class, driving ability (consult local official guidance on driving health)
    • Smoking
    • Use of hypnotics, sedatives and analgesics with central nervous system effects
  • Clinical findings
    • Findings from auscultation of the heart and lungs
    • Weight, BMI, waist circumference
    • Blood pressure
    • Assessment of structures predisposing to sleep apnoea
      • Length and thickness of the neck
      • If the nose narrow and congested? (allergic rhinitis, polyps, deviated septum, history of injuries)
      • Is there narrow pharynx; long, slack soft palate; large tongue and tonsils, large uvula?
      • Size and abnormal proportions of the face and jaws, such as small or backward-sloping lower jaw, malocclusion
    • The teeth as well as the mobility of the jaw should be checked, considering the suitability of a mandibular advancement device.
  • Exclusion of other factors or concomitant diseases causing fatigue: basic blood count with platelet count, HbA1c, lipids and thyroid function tests, ECG
    • In an overweight patient, basic investigations for metabolic syndrome should also be included Metabolic Syndrome
  • The pre-test probability of sleep apnoea can be assessed with the STOP-Bang questionnaire, see www.stopbang.ca/translation/pdf/enguk.pdf.
  • The diagnosis of sleep apnoea is normally based on limited night polygraphy usually done at home or, in special cases, at a sleep laboratory. If, in addition to breathing during sleep, information is needed on the quality of sleep, sleep polygraphy with EEG should be performed.

Differential diagnosis

Referral for specialized care

  • There are local differences in work division between specialized care and primary health care. Find out about local policies and practices.
  • Night polygraphy and the diagnosis of sleep apnoea are usually required before referral for specialized care.
  • At least two of the following are required for non-urgent referral:
    • daytime fatigue
    • abnormal sleep attacks
    • loud snoring over a long period of time
    • episodes of apnoea verified by another person
    • morning headache (accumulation of carbon dioxide during sleep)
    • repeated nightly awakenings with a feeling of suffocation
    • memory or mood disorder possibly associated with sleep apnoea
    • suspicion of hypoventilation associated with obesity.
  • Urgent sleep apnoea investigations should be initiated:
    • If a patient with symptoms works in an occupation requiring particular alertness (e.g. professional drivers, engine drivers, pilots or people working in air traffic control)
    • If the patient has a severe cardiovascular disease
    • If sleep apnoea is suspected in a pregnant woman
    • Before any procedure is carried out under general anaesthesia.
  • Polysomnography is necessary for differential diagnostic problems in cases where limited night polygraphy does not yield a diagnosis. This concerns various parasomnias, hypersomnias and various forms of mild sleep apnoea.

Lifestyle treatment

  • Primary health care plays a central role in the lifestyle treatment of sleep apnoea.
  • Weight reduction and weight management constitute the first and most important treatment measures for every overweight patient with obstructive sleep apnoea http://www.dynamed.com/condition/obstructive-sleep-apnea-osa-in-adults#WEIGHT_REDUCTION_IF_OBESE_.
  • Physical activity alleviates sleep apnoea regardless of weight changes.
  • Positional therapy, i.e. avoidance of sleeping on one's back, is useful in the treatment of mild obstructive sleep apnoea dependent on the sleeping position.
  • Hypnotics and sedatives, as well as drinking alcohol before going to bed, must be avoided (these tend to increase the frequency and duration of apnoea episodes).
  • Treatment of nasal congestion
  • Smoking cessation decreases mucosal swelling.
  • Optimal treatment should be provided for underlying diseases, such as diabetes mellitus, hypertension, hypothyroidism and obstructive pulmonary diseases.

Mechanical aids Pressure Modification for Improving Usage of Cpap Machines for Obstructive Sleep Apnoea, Impact of Cpap on Blood Pressure in Obstructive Sleep Apnoea, Interventions to Improve Usage of Cpap Machines in Obstructive Sleep Apnoea

  • Continuous positive airway pressure (CPAP) is effective and the first-line treatment of moderately severe to severe obstructive sleep apnoea Cpap for Obstructive Sleep Apnoea.
    • In nasal CPAP, a slight positive pressure preventing the obstruction of the upper airways during sleep is maintained with a nasal mask.
    • The patient's symptoms, occupation, other diseases, risks associated with sleep apnoea and polysomnographic findings must be considered when evaluating the need for treatment.
    • This treatment is usually started in pulmonary medicine units.
    • CPAP treatment is effective only if used regularly. At least 4 h/night is usually recommended.
    • More than half of patients comply well with long-term nasal CPAP treatment. Problems related to the treatment include air leaks around the mask, nasal congestion, runny nose, noise from the pressure apparatus, epistaxis, and mouth dryness.
    • CPAP apparatuses are classified as rehabilitation aids, and they may be available to patients free of charge, e.g. under a lending agreement. Find out about local practices.
    • Today, follow-up takes place, depending on local policies and care pathways, increasingly remotely or at symptom outpatient clinics.
      • Professional drivers and other people working in occupations requiring particular alertness are followed up in specialized care.
    • The indications for nasal CPAP should be re-evaluated if the patient loses weight or undergoes surgery for sleep apnoea.
  • Central sleep apnoea is treated by a special breathing device (CSA/ASV, adaptive servo ventilation). This treatment is not suitable if the patient has heart failure. CPAP therapy may also be tried.
  • Mandibular advancement devices moving the lower jaw and tongue muscles forward are used to treat particularly mild to moderately severe sleep apnoea in patients with normal weight or who are overweight (BMI 25-35 kg/m2) and patients who do not comply well with CPAP treatment Oral Appliances for Obstructive Sleep Apnoea.
    • The individual suitability of treatment with mandibular advancement devices should be assessed in oral health care according to local policies and care pathways.
    • A dental check-up with treatment as indicated is needed before treatment with a mandibular advancement device.

Surgical treatment Surgery for Obstructive Sleep Apnoea

  • Upper respiratory tract or facial surgery can be considered in selected patients if conservative treatment of sleep apnoea (lifestyle treatment, CPAP treatment or treatment with a mandibular advancement device) is insufficient, if the patient cannot tolerate such treatment or if he/she has structural causes of sleep apnoea in the pharynx or face that can be treated surgically.
    • Depending on the level of obstruction, treatment is planned either for one (nose, pharynx, soft palate, etc.) or several levels (multilevel surgery).
    • Evidence of the effects of surgical treatment of sleep apnoea is scant and contradictory.
  • In selected patients, maxillofacial surgery of the upper and lower jaws can permanently increase the air space in the hypo- and oropharynx.
  • Bariatric surgery Bariatric Surgery (Obesity Surgery) can be considered in patients with BMI > 35 kg/m2 .

References

  • Uniapnea (obstruktiivinen uniapnea aikuisilla) [Sleep apnoea (obstructive sleep apnoea in adults)]. A Currect Care Guideline. Working group appointed by the Finnish Medical Society Duodecim, the Finnish Respiratory Society and the Finnish Sleep Research Society. Helsinki: the Finnish Medical Society Duodecim, 2022 (accessed 2 Mar 2023). In Finnish http://www.kaypahoito.fi/hoi50088.
  • Peppard PE, Young T, Barnet JH, et al. Increased prevalence of sleep-disordered breathing in adults. Am J Epidemiol 2013;177(9):1006-14 [PubMed]
  • Palomäki M, Saaresranta T, Anttalainen U, et al. Multimorbidity and overall comorbidity of sleep apnoea: a Finnish nationwide study. ERJ Open Res 2022;8(2): [PubMed]
  • Strausz S, Havulinna AS, Tuomi T, et al. Obstructive sleep apnoea and the risk for coronary heart disease and type 2 diabetes: a longitudinal population-based study in Finland. BMJ Open 2018;8(10):e022752 [PubMed]
  • Edwards BA, Jordan AS, Schmickl CN, et al. POINT:: Are OSA Phenotypes Clinically Useful? Yes. Chest 2023;163(1):25-28 [PubMed]

Evidence Summaries