Sleep Apnoea

Definition/diagnostic criteria Obstructive Sleep Apnoea/Hypopnoea Syndrome (OSAHS), is a condition where the upper airway narrows or closes during sleep when muscles relax. This leads to under-breathing (hypopnoea) or stopping of breathing (apnoea), causing the person to wake or lighten sleep, resulting in disrupted sleep and potential excessive sleepiness​​.

Epidemiology In the UK, obstructive sleep apnoea syndrome (OSAS) affects all age groups. Approximately 4% of middle-aged men and 2% of middle-aged women are impacted. OSAHS affects around 5% of UK adults. An estimated 1.5 million adults have OSA, but up to 85% remain undiagnosed and untreated. Among individuals aged 30 to 70, 5% have moderate or severe OSA based on sleep studies, and a further 20% have mild OSA, making a total of 25% of this age group with mild, moderate, or severe OSA (8 million people)​​.

Diagnosis

Clinical features The clinical features of OSAHS include episodes of under-breathing or apnoea during sleep, leading to disrupted sleep patterns and excessive daytime sleepiness.

Investigations Diagnostic investigations for OSAHS include home respiratory polygraphy for suspected cases. If access to this is limited, home oximetry may be considered, though it may be less accurate in differentiating OSAHS from other causes of hypoxaemia in individuals with heart failure or chronic lung diseases. Polysomnography or respiratory polygraphy may be considered if oximetry results are negative but significant symptoms persist. In some cases, hospital respiratory polygraphy or polysomnography might be necessary​​.

Treatment Treatment strategies for OSAHS vary based on severity:

Mild OSAHS Lifestyle advice is the primary approach, including weight loss, smoking cessation, reduced alcohol intake, and improved sleep hygiene. Continuous Positive Airway Pressure (CPAP) may be offered if symptoms affect quality of life and usual activities, and if lifestyle changes alone are ineffective or inappropriate. Alternatives like auto-CPAP or mandibular advancement splints can be considered based on individual needs and tolerances​​.

Moderate and severe OSAHS CPAP, in addition to lifestyle advice, is recommended. Alternatives include auto-CPAP and mandibular advancement splints, especially for those unable to tolerate CPAP or with specific medical conditions​​.

Prognosis Follow-up and monitoring are crucial for OSAHS management. Tailored follow-ups should consider the overall treatment plan, including lifestyle changes and managing comorbidities. Monitoring treatment efficacy includes evaluating OSAHS symptoms, severity, adherence to therapy, and reviewing telemonitoring data or device download information. Treatment may be stopped if OSAHS resolves, for example, with significant weight loss, but re-evaluation of symptoms and a sleep study should be considered​​.