2.16 Sleep Apnea

Pulmonary system review for the USMLE Step 1 Exam

• Sleep apnea is the repeated severe decrease or cessation of airflow into the lungs for more than 10 seconds during sleep, which causes the person to stop breathing for more than 10 seconds while they’re sleeping.
• There are two types of sleep apnea: obstructive sleep apnea and central sleep apnea.
• Obstructive sleep apnea occurs when the airway collapses during sleep, and it is more likely to be associated with snoring, gasping, and choking.
• Central sleep apnea occurs when breathing cessations are caused by decreased central nervous system respiratory drive, and it is more likely to be associated with Cheyne-Stokes respirations.
• Sleep apnea can cause hypertension, pulmonary hypertension, cardiac arrhythmias, and even sudden death.
• The most common symptom patients will present with is daytime sleepiness, and obesity is associated with obstructive sleep apnea.
• Diagnosis relies heavily on testing, and the gold standard for diagnosis of sleep apnea is a sleep study (a laboratory polysomnography).