Severe Cyanosis in a Toddler

A 15-month-old boy presented to the emergency department for evaluation of irritability and shortness of breath. Upon initial presentation, he was notably cyanotic with an oxygen saturation of 75%, which dropped precipitously to 15% with oxygen administration and agitation. He also had a short, harsh, III/VI early systolic ejection murmur loudest at the left sternal border that terminated mid-systole and prominent digital clubbing. The patient was calmed by parental soothing and intravenous medication.

source https://www.jpeds.com/article/S0022-3476(21)00912-4/fulltext?rss=yes