The respiratory event that requires oxygen desaturation and/or an arousal as part of the scoring criteria is:

The respiratory event that requires oxygen desaturation and/or an arousal as part of the scoring criteria is:

• A. Obstructive hypopnea
• B. Mixed apnea
• C. Hypoventilation
• D. Cheyne Stokes

Answer: (A)

In sleep-scoring, a hypopnea is a partial drop in airflow that lasts at least 10 seconds and is counted only if it’s accompanied by an oxygen desaturation of at least 3% or an arousal from sleep. When the event is due to partial obstruction of the airway while respiratory effort continues, it’s labeled obstructive hypopnea. That combination—reduced airflow plus a desaturation or arousal as part of the criteria—matches the description given in the question, making obstructive hypopnea the best choice. The other terms describe different patterns. Mixed apnea involves a transition from obstruction to a central pause and is defined by the presence of a complete pause in airflow rather than a partial reduction with desaturation/arousal as a requirement. Hypoventilation is a sustained failure of ventilation leading to elevated CO2, not a discrete event defined by desaturation/arousal criteria. Cheyne-Stokes refers to a periodic breathing pattern, not a single hypopneic event.

In sleep-scoring, a hypopnea is a partial drop in airflow that lasts at least 10 seconds and is counted only if it’s accompanied by an oxygen desaturation of at least 3% or an arousal from sleep. When the event is due to partial obstruction of the airway while respiratory effort continues, it’s labeled obstructive hypopnea. That combination—reduced airflow plus a desaturation or arousal as part of the criteria—matches the description given in the question, making obstructive hypopnea the best choice.

The other terms describe different patterns. Mixed apnea involves a transition from obstruction to a central pause and is defined by the presence of a complete pause in airflow rather than a partial reduction with desaturation/arousal as a requirement. Hypoventilation is a sustained failure of ventilation leading to elevated CO2, not a discrete event defined by desaturation/arousal criteria. Cheyne-Stokes refers to a periodic breathing pattern, not a single hypopneic event.