Obstructive sleep apnea basics

September 3, 2019|Cleveland Clinic Journal of Medicine
Jessica Vensel Rundo, MD, MS
Author and Disclosure Information

Jessica Vensel Rundo, MD, MS
Sleep Fellowship Program Director, Sleep Disorders Center, Neurological Institute, Cleveland Clinic

Correspondence: Jessica Vensel Rundo, MD, MS, Sleep Disorders Center, S73, Cleveland Clinic, 9500 Euclid Avenue, Cleveland, OH 44195; venselj@ccf.org

Dr. Vensel Rundo reported no financial interests or relationships that pose a potential conflict of interest with this article.

This article is based on Dr. Vensel Rundo’s “Obstructive Sleep Apnea Basics” webcast released January 30, 2019, part of the “Obstructive Sleep Apnea: A Cleveland Clinic State-of-the-Art Review” online series (available at www.clevelandclinicmeded.com/online/sleep-apnea). The article was drafted by Cleveland Clinic Journal of Medicine staff and was then reviewed, revised, and approved by Dr. Vensel Rundo.

Release date: September 1, 2019
Expiration date: August 31, 2022
Estimated time of completion: 0.75 hour

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ABSTRACT

Obstructive sleep apnea (OSA) is a condition caused by repeated episodes of upper airway collapse and obstruction during sleep associated with arousal from sleep with or without oxygen desaturation. OSA is a highly prevalent condition, particularly in individuals with established risk factors and comorbid conditions. Screening for OSA includes a sleep history, review of symptoms, and physical examination, the results of which can identify patients that need testing for OSA. The polysomnogram or home sleep apnea test results aid in the diagnosis of OSA and its severity.

KEY POINTS

  • OSA is characterized by repeated episodes of complete or partial obstruction of the airway during sleep.
  • The prevalence of OSA is underestimated and underdiagnosed.
  • A sleep history, simple upper airway examination, and quick validated screening tool like the STOP-BANG or Epworth Sleepiness Scale aid in identifying the need for testing for OSA.
  • Polysomnogram is the gold standard for evaluation of OSA. Home sleep apnea tests can be used to confirm a diagnosis of OSA in patients at high risk for moderate to severe OSA.

SCREENING

Screening patients for OSA starts with a good sleep history to identify symptoms, risk factors, and comorbid conditions, as well as a physical examination for OSA-related features (Table 2). The Epworth Sleepiness Scale and STOP-BANG questionnaire are brief, effective screening tools that can inform the need for further testing.

Sleep history

A sleep history starts with determining the patient’s total sleep time, based on time to bed, time to fall asleep, and time of wake up, including any difficulty falling asleep, staying asleep, or daytime naps.

Symptoms. Daytime naps generally indicate a sleep deficit or sleep that is not refreshing. A review of sleep and daytime symptoms associated with OSA (Table 1) helps determine if excessive daytime sleepiness or unrefreshing sleep is out of proportion with the amount of sleep the patient is getting at night.

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Some patients with OSA may have memory or concentration issues or feel like they have attention deficit disorder. In fact some patients are diagnosed with attention deficit disorder because of their insufficient sleep or unrefreshing sleep.

Drowsy driving is a special concern in patients with untreated OSA and sleep deprivation. Many patients have drowsy driving episodes or difficulty staying awake during long-distance driving. Caffeine use is also important information as excessive caffeine may be used to combat sleepiness during the day.

The Epworth Sleepiness Scale is a clinical screening tool that presents 8 situations for patients to consider and indicate their level of sleepiness and likelihood of falling asleep (never = 0; slight = 1; moderate = 2, high = 3).21,22 A total score ≥ 10 is considered abnormal in that the patient is excessively sleepy compared with most people.

Risk factors and comorbid conditions. OSA risk factors and comorbidities, including a BMI obesity assessment, should be reviewed with patients. Nasal congestion or mouth breathing especially at night could be due to airway obstruction increasing the risk of OSA. Family history of OSA, tobacco, alcohol use, other medical conditions, and medications should also be discussed.

Physical examination

Figure 1. Friedman palate positions (classes 1, 2, 3, and 4).
Certain findings on physical examination could suggest the presence of OSA:
  • Neck circumference greater than 17 inches for men or greater than 16 inches for women
  • BMI greater than 30
  • Friedman class tongue position class 3 or greater (Figure 1)
  • Mouth features (present/enlarged tonsils, macroglossia, jaw misalignment)
  • Nasal abnormalities (turbinate hypertrophy, deviated septum).5

Patients with Friedman palate positions class 3 and 4 have a higher risk of OSA due to airway crowding during sleep when the airway naturally collapses a little and is even more restricted.

Narrow airways or oropharyngeal crowding can also be due to a swollen, enlarged, or elongated uvula; present or enlarged tonsils; or lateral wall narrowing. Alone or in combination, these features can contribute to airway obstruction.

Other signs in the mouth suggestive of obstruction are macroglossia (enlarged tongue) and tongue ridging. Tongue ridging or scalloping impressions typically occur during sleep and are caused by the tongue moving forward to open the airway and pressing against the teeth.

Retrognathia (lower jaw offset behind upper jaw) can narrow the airway and increase the risk of OSA as can a high arch palate, overbite (upper teeth forward), or overjet (upper teeth over the top of lower teeth).

A nasal examination for nasal valve collapse (ie, nostril collapses with inhalation), deviated septum, and inferior turbinate hypertrophy impart an increased risk of OSA.

Screening tools

In addition to the Epworth Sleepiness Scale, the STOP-BANG questionnaire can help determine if a patient should be tested further for OSA. The STOP-BANG questionnaire consists of 8 yes-no questions where more than 2 yes responses indicate the patient is at higher risk for moderate to severe OSA (93% sensitivity): Snore, Tired, Observed stopped breathing, high blood Pressure, BMI > 35 kg/m2, Age > 50, Neck > 15.75 inches, Gender = male).23