course material

1. Pneumocytis Pneumonia
discussion 1 Clinical case scenarioA 39-year-old homeless man presents to the emergency
department for cough and fever. He says that his illness has been worsening over the past 2
weeks. He originally had dyspnea on exertion and now is short of breath at rest. On
questioning, he tells you that he lives in a homeless shelter when he can, but he frequently
sleeps on the streets. He has used IV drugs (primarily heroin) “on and off” for many years.
He denies medical history but the only time he gets medical attention is when he comes to
the emergency department for an illness or injury. On review of systems, he complains of
fatigue, weight loss, and diarrhea. On examination, he is a thin, disheveled man appearing
much older than his stated age. His temperature is 100.5°F (38.0°C), his blood pressure
is 100/50 mm Hg, his pulse is 105 beats/min, and his respiratory rate is 24 breaths/min.
His initial oxygen saturation is 89% on room air, which comes up to 94% on 4 L of oxygen
by nasal cannula. Significant findings on examination include dry mucous membranes, a
tachycardic but regular cardiac rhythm, a benign abdomen, and generally
wastedappearing extremities. His pulmonary examination is significant for tachypnea and
fine crackles bilaterally, but no visible signs of cyanosis. His chest x-ray is read by the
radiologist as having diffuse, bilateral,interstitial infiltrates that look like “ground
glass.”Answer the following questions1-What is the most likely cause of this patient’s
current pulmonarycomplaints?2-What underlying illness does this patient most likely
have? 3-What testing and treatment should be started now?