In Episode 10 of Med School Question of the Week for USMLE, Luke Maxfield, MedSchoolCoach expert tutor, answers this medical school question: A 64-year old woman comes to the emergency department with the complaint of shortness of breath. The patient has a history of chronic tobacco use, diabetes, congestive heart failure, and hypertension. The patient’s medications include albuterol, lisinopril, metoprolol, aspirin, and metformin. The patient states that over the last few weeks she has become more short of breath. She has recently begun to sleep in a recliner due to an inability to lay flat. The patient’s temperature is 36.6 Celsius (98F), blood pressure is 91/58 mmHg, heart rate is 110/min and regular, respirations are 23/min with 02 at 90% by pulse oximetry. The physical exam reveals bibasilar rales and diminished breath sounds at the lung bases. The plain film is provided. What is the most appropriate next step?