Intensive Care Medicine (ICM) Practice Exam

What is the primary pathogenesis of obstructive sleep apnea that leads to inability to get restful sleep?

1. Transiently abolishing neurological impulses to the respiratory muscles

2. Compromising the patency of the airway, usually at the pharynx

3. Hypothyroidism causes a decrease in oxygen saturation, leading to gasping for air at night

4. Snoring wakes the spouse, who then wakes up the patient out of complaint

The correct answer is: Compromising the patency of the airway, usually at the pharynx

The primary pathogenesis of obstructive sleep apnea (OSA) is the compromise of airway patency, particularly at the level of the pharynx. During sleep, the muscles of the throat relax, and in individuals predisposed to OSA, this relaxation can lead to the collapse of the upper airway. When the airway is compromised, airflow is obstructed despite the effort to breathe, resulting in periods of apnea (breathing cessation) or hypopnea (shallow breathing). This blockage of airflow leads to fragmented sleep patterns and reduces overall sleep quality, as the body may awaken briefly to resume normal breathing. As a result, individuals suffering from obstructive sleep apnea often experience daytime sleepiness and a feeling of unrefreshing sleep, even if they spend sufficient time in bed. Other potential causes or symptoms associated with obstructive sleep apnea, such as transient cessation of respiratory muscle impulses or factors like snoring, are secondary to the main issue of airway obstruction. While hypothyroidism might influence overall sleep and systemic oxygenation, it is not directly responsible for the sleep disturbances characteristic of obstructive sleep apnea. Thus, compromising the patency of the airway is the correct and primary mechanism that leads to the inability to achieve restful sleep in these patients