I recently had a patient who was in severe respiratory distress. Pt was very pale and diaphoretic. He looked like a pre arrest pt. Pt was a 40-50s male. Pt denied any chest pain and had no other complaints aside from severe dyspnea. Pts only medical hx was an MI. Pts wife stated she “thinks” pt presented similarly with his previous MI. Pt had no wheezing upon auscultation and good air-entry, nothing obvious on 12 lead. Pt was tachy and Spo2 was 80% on room air but improved with NRB. Pt was otherwise vitally stable. My question- how would you treat this patient? Pt was impossible to get a hx from. He had 2-3 word dyspnea and got extremely agitated trying to answer questions and pts wife was also no help. I felt like I didn’t have enough info to make a decision. We treated with high flow oxygen. We felt like it could have been a PE, undiagnosed COPD or cardiac but it wasn’t clear cut either way