What respiratory event is defined by requiring oxygen desaturation and/or an arousal for scoring?

The definition of an obstructive hypopnea involves a reduction in airflow due to the collapse of the upper airway, which often leads to a decrease in oxygen saturation levels and can also cause arousals from sleep. This event is specifically characterized by a significant drop in respiratory airflow that is associated with decreased oxygen saturation—generally specified as a reduction of at least 30% in airflow from baseline for at least 10 seconds.

In the context of scoring sleep studies, the requirement of either an oxygen desaturation or an arousal makes this event particularly important for identifying and diagnosing obstructive sleep apnea (OSA). Obstructive hypopneas often serve as indicators of airway resistance and associated respiratory dysfunction during sleep, necessitating their inclusion in scoring criteria for sleep studies.

Other events mentioned, such as central apnea and sleep-related hypoventilation, do not have the same scoring requirements related to desaturation or arousal, nor do they necessarily originate from obstructive airway events like obstructive hypopnea. Periodic limb movement disorder is primarily related to limb movements rather than respiratory events and does not involve scoring based on oxygen saturation or arousals related to respiratory functions.