clinical assessment of possible obstructive in an adult sleep apnoea

Last edited 09/2021 and last reviewed 12/2022

A high index of suspicion of obstructive sleep apnoea syndrome (OSAS) is necessary to allow the diagnosis to be made since many patients initially present with non specific symptoms. The following question should be asked from the patient if OSAS is suspected

  • any evidence of  snoring
  • does the snoring occur when the patient is in a particular position
  • history of upper airway surgery
  • any witnessed breathing interruptions or choking episodes during sleep
  • how long does the patient sleep
  • whether he/she feels refreshed on waking
  • any daytime sleepiness, poor concentration, or poor memory
  • about any road traffic incidents or near misses when driving
  • nocturia
  • headaches in the early morning
  • loss of libido

Presence of snoring and witnessed apnoeas with symptoms of sleep fragmentation, such as excessive daytime sleepiness suggests OSAS (1)
A subjective assessment of sleepiness can be carried out using the Epworth sleepiness scale.

  • scores greater than 10 are usually taken to imply excessive daytime sleepiness and investigations are usually recommended

  • the scale should be completed independently by both the patient and their partner as the patient may underestimate the severity of their sleepiness due to its insidious onset, or in order to hide concerns over driving ability (3)

In addition screening tools such as Berlin questionnaire and STOP-Bang questionnaire (with sensitivities of about 85%) may be used as diagnostic aids in primary care and preoperative settings (2).

The following examinations may help to exclude other causes for the patient's symptoms

  • body mass index, neck circumference
  • blood pressure
  • thyroid assessment
  • assessment for nasal obstruction and retrognathia
  • oral examination for tonsillar enlargement and oropharyngeal crowding

NICE state (3):

Initial assessment for OSAHS (Obstructive sleep apnoea/hypopnoea syndrome)

When to suspect OSAHS

  • take a sleep history and assess people for OSAHS if they have 2 or more of the following features:
    • snoring
    • witnessed apnoeas
    • unrefreshing sleep
    • waking headaches
    • unexplained excessive sleepiness, tiredness or fatigue
    • nocturia (waking from sleep to urinate)
    • choking during sleep
    • sleep fragmentation or insomnia
    • cognitive dysfunction or memory impairment

Be aware that there is a higher prevalence of OSAHS in people with any of the following conditions:

  • obesity or overweight
  • obesity or overweight in pregnancy
  • treatment-resistant hypertension
  • type 2 diabetes
  • cardiac arrythmia, particularly atrial fibrillation
  • stroke or transient ischaemic attack
  • chronic heart failure
  • moderate or severe asthma
  • polycystic ovary syndrome
  • Down's syndrome
  • non-arteritic anterior ischaemic optic neuropathy (sudden loss of vision in 1 eye due to decreased blood flow to the optic nerve)
  • hypothyroidism
  • acromegaly

Assessment scales for suspected OSAHS

  • when assessing people with suspected OSAHS:
    • use the Epworth Sleepiness Scale in the preliminary assessment of sleepiness
    • consider using the STOP-Bang Questionnaire as well as the Epworth Sleepiness Scale
    • do not use the Epworth Sleepiness Scale alone to determine if referral is needed, because not all people with OSAHS have excessive sleepiness

Reference:

Related pages:

obstructive sleep apnoea (OSA)