First AD

Second AD

Results of an annual physical examination of a 54-year-old man have led you to suspect he may have-or be at high risk for-sleep apnea syndrome. His BMI is 37 and his blood pressure is 126/82 mm Hg. He has hypertension and hyperlipidemia. He reports restful sleep and no daytime sleepiness.  

The  clinical characteristics that raise your suspicion are: BMI greater than 35, a history of hypertension, and male sex. These are 3 of 8 risk factors for sleep apnea identified by the 

. The presence of 3 or more factors is sufficient  to confer a high risk of the disorder.

You refer him for polysomnography (sleep laboratory testing) and receive the following test results:

- Apnea-hypopnea index of 22
- 20 obstructive apneas
- 10 mixed apneas
- 22 central apneas
- 80 hypopneas
- Lowest oxygen saturation 82%
- 12 awakenings and 32 arousals

International Classification of Sleep Disorders,

 third edition, the diagnosis of obstructive sleep apnea is established as follows (paraphrased):

A. Complaints of sleepiness, nonrestorative sleep, fatigue, or insomnia; or awakenings with breath holding, gasping, or choking; or observed habitual snoring, breathing interruptions; history of hypertension, a mood disorder, cognitive dysfunction, coronary artery disease, stroke, congestive heart failure, atrial fibrillation, or type 2 diabetes mellitus

B. Polysomnography demonstrates 5 or more predominantly obstructive respiratory events (obstructive and mixed apneas, hypopneas, or respiratory event-related arousals  [RERAs]) per hour of sleep

OR

Fifteen or more predominantly obstructive respiratory events (apneas, hypopneas, or RERAs) per hour of sleep.


OSA is characterized by repetitive episodes of complete (apnea) or partial (hypopnea) upper airway obstruction occurring during sleep. These events often result in reductions in blood oxygen saturation and are usually terminated by brief arousals from sleep. Since the predominant types of obstruction in this patient are obstructive in nature (obstructive apneas, mixed apneas, and hypopneas comprise the majority of events), the proper diagnosis is obstructive sleep apnea. Arousals and awakenings are common in OSA patients, and usually related to the severity of the condition; a diagnosis of insomnia is not appropriate unless the patient complains of difficulty in sleep initiation or maintenance, which this patient does not; in addition, a diagnosis of insomnia is made on the basis of subjective complaint, not polysomnography.

   • OSA is characterized by repetitive episodes of complete (apnea) or partial (hypopnea) upper airway obstruction occurring during sleep

   • If OSA is clinically suspected, diagnosis is established by polysomnographic testing

To review the earlier portion of this case, 

International Classification of Sleep Disorders

. 3rd ed. Darien, IL: American Academy of Sleep Medicine; 2014.
 

Sleep Disorders

Results of this sleep study help diagnose the specific type of sleep apnea.  Evidence of 5 or more predominantly obstructive respiratory events per hour of sleep suggests obstructive disease.

Polysomnography Unmasks Sleep Apnea