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

In the context of polysomnography findings, increased chest movement coupled with the absence of nasal airflow is indicative of obstructive sleep apnea (OSA). In OSA, there are episodes where the child attempts to breathe, as evidenced by the chest movements, but these efforts are met with a blockage in the airways, preventing airflow through the nose.

In this scenario, the chest movement suggests that the respiratory muscles are actively trying to work to draw in air, which can occur when there is an obstruction present despite the child being unable to actually inhale through the nasal passages. This pattern is characteristic of obstructive apnea, where normal respiratory efforts are made against an obstructed airway.

Other potential conditions do not align with this combination of findings. For example, central sleep apnea would typically present as both a lack of respiratory effort and airflow due to a failure of the brain to send signals to the muscles that control breathing, which does not match the scenario described. Similarly, mixed central and obstructive sleep apnea includes both obstructive and central mechanisms, but the specific finding of increased chest movement without airflow strongly points toward pure obstruction. A normal sleep study would show consistent respiratory patterns with no interruptions in airflow or chest movement.

Thus, the presence of increased chest movement without nasal