A 67 year old male patient on an orthopedic unit, post-op day 2 with a DVT in R calf. Heparin protocol was initiated. Patient has a history of a previous anterior myocardial infarction (MI) 12 months ago with placement of 2 stents. V/S have been stable over the night shift with no complaints. Patient is mildly short of breath and complaining of mild chest pain. 02 saturation (sat) is 90% on room air. Heparin has been infusing at sub-therapeutic rate. Patient is diagnosed with PE and condition worsens to respiratory failure requiring placement of advanced airway and mechanical ventilation.