Obstructive Sleep Apnea (OSA)

Primer

Obstructive Sleep Apnea (OSA) is a sleeping disorder characterized by multiple episodes of cessation of breathing, lasting at least 10 seconds with desaturations and arousals. OSA also involves episodes of upper (pharyngeal) airway obstruction (apneas and hypopneas) during sleep. Apnea is the complete obstruction of airflow, and hypopnea is a reduction in airflow. It is the most common breathing-related sleep disorder.

Prevalence

OSA affects 1-2% of children, 2-15% of middle-age adults, and more than 20% of older individuals. Undiagnosed OSA may be very high in elderly individuals. Since it is strongly associated with obesity, areas with high obesity rates also likely to have high rates of OSA.

Diagnostic Criteria

Criterion A

Either item (1) or (2) is present:

  1. Evidence by polysomnography of at least 5 obstructive apneas or hypopneas per 1 hour of sleep and either of the following sleep symptoms: (A) Nocturnal breathing disturbances: snoring, snorting/gasping, or breathing pauses during sleep. AND/OR (B) Daytime sleepiness, fatigue, or unrefreshing sleep despite sufficient opportunities to sleep that is not better explained by another mental disorder (including a sleep disorder) and is not attributable to another medical condition.
  2. Evidence by polysomnography of 15 or more obstructive apneas and/or hypopneas per hour of sleep regardless of accompanying symptoms
Specifiers

Severity Specifiers

Specify if:

  • Mild: Apnea hypopnea index is less than 15.
  • Moderate: Apnea hypopnea Index is 15-30.
  • Severe: Apnea hypopnea index is greater than 30.
Signs and Symptoms

Snoring, gasping for air, stopping breathing at night, memory complaints, irritability, depression, morning headaches, sexual problems, restless sleep, and sedation or tiredness during the day.

Apnea-Hypopnea Index (AHI)

Apnea-Hypopnea Index (AHI)

AHI (events/hours) Severity
0-5 Normal
5 - 15 Mild sleep apnea
15 - 30 Moderate sleep apnea
>30 Severe sleep apnea
Remember, 5 apneas within an hour are actually considered within normal range (apnea is > 10 seconds)

Screening

The STOP-BANG is a screening tool that has been validated for the identification of obstructive sleep apnea.[1][2] If more than 4 criteria are met, there is a sensitivity of 80% and specificity of 50%.

Psychometric Scales for Depression

Name Rater Description Download
STOP-Bang Questionnaire Patient or Physician The STOP-BANG questionnaire screens for obstructive sleep apnea (OSA) only, not central sleep apnea. STOP-BANG Download

Pathophysiology

Children

There is a peak of OSA in children ages 3-8 years, this is when the nasopharynx can compromised by a relatively large mass of tonsillar tissue compared with the size of the upper airway. As the airway grows and develops during childhood, there is regres sion of lymphoi d tissue, there is reduction in the incidence of OSA.

Adults

The major risk factors for obstructive sleep apnea hypopnea are obesity and male gender. As obesity prevalence increases in midlife and females enter menopause, obstructive sleep apnea hypopnea again increases.

Anatomy

Maxillary-mandibular retrognathia or micrognathia, genetic syndromes that reduce upper airway patency (e.g., Down's syndrome, Treacher Collin's syndrome), adenotonsillar hypertrophy (especially in young children), and various endocrine syndromes (e.g., acromegaly) all increase the risk of OSA due to anatomical changes to airway patency.

Treatment

  • Weight loss and lifestyle changes
  • Surgical intervention
  • Dental Device
  • CPAP
  • EPAP

Clinical Pearls

  • CPAPs are not a panacea and may not always be prescribed properly!
  • CPAPs can cause more insomnia if your patients are unable adjust to using a CPAP
  • Patients are more prone to have REM apnea, because muscle paralysis occurs during REM
  • The snoring is not what causes apnea – it’s the collapse of the airway that is the problem!
Important Questions to Ask on History
  • Is it obstructive or central?
  • How severe it is?
  • Is it REM-related?
  • Is it positional?
    • Does your patient sleep on their back or sleep on their side?
  • Is it associated with desaturations?
  • Are there medical comorbidities?

Differential Diagnosis

  • Primary snoring and other sleep disorders
  • Insomnia disorder
  • Panic attacks (nocturnal)
  • Attention-deficit/hyperactivity disorder
  • Substance/medication-induced insomnia or hypersomnia

Resources

For Patients

For Providers

Articles
Research

References

1) STOP-Bang Questionnaire
2) Popević, M. B., Milovanović, A., Nagorni-Obradović, L., Nešić, D., Milovanović, J., & Milovanović, A. P. (2017). Screening commercial drivers for obstructive sleep apnea: Validation of STOP-Bang questionnaire. International Journal of Occupational Medicine and Environmental Health, 30(5), 1-11.