A patient recovering from hip surgery begins to ambulate for the first time about 2 hours postoperatively. Suddenly, they experience shortness of breath. The patient becomes tachypneic and tachycardic and experiences pain on inspiration. Prior to getting out of bed, their postoperative course was unremarkable. There is no swelling; there is no palpable thrill at the incision site.
Question
What is your initial diagnosis?
1 Postoperative pneumonia
2 Atelectasis
3 Arteriovenous fistula at surgical site
4 Pulmonary embolism
5 Abdominal aortic aneurysm rupture