These videos aren't all inclusive, there were some times that his breathing just sounded rapid or almost asthmatic. This is the most obvious sleep apnea. The episodes aren't as loud as adult sleep apnea.
In this video, the sleep apnea episode is at the beginning, and ends when he wakes up fully from the sleep apnea.
This video is a good example of how a child might posture themselves in their sleep to help alleviate the sleep apnea.