What condition is indicated by a child having increased chest movement but no nasal airflow during polysomnography?

In the scenario described, the indication of increased chest movement with no nasal airflow during polysomnography points towards a specific type of breathing disorder during sleep. When a child exhibits active chest movement but does not have airflow through the nose, this suggests that while the respiratory muscles are attempting to function (hence the chest movement), there is a block in the airway preventing airflow.

This phenomenon is characteristic of obstructive sleep apnea. In obstructive sleep apnea, the airway becomes intermittently blocked, leading to episodes of apnea where the child is trying to breathe but can't due to the obstruction. Thus, the chest raises as the muscles work to create a breath, but the air can't pass through the obstructed airway.

In contrast, central sleep apnea would typically show a lack of both airflow and respiratory effort. Mixed sleep apnea would have components of both obstructive and central events, but the absence of nasal airflow combined with active chest effort is predominantly aligned with obstructive sleep apnea. Normal findings during a sleep study would typically not show this mismatch between chest movement and airflow, reinforcing that the correct interpretation here is obstructive sleep apnea.