Case Presentation: A 3-year-old female presented with 1-day of fatigue, pallor, dyspnea and dry cough. Vital signs showed HR 152, RR 28, temp 98.8 F, BP 101/67, and oxygen saturation of 75% on room air. On exam, she was well appearing, with clear lungs and no respiratory distress despite the desaturations. Initial testing showed a [...]