Sorry for the delay on this one everyone. Image of the Week 007 below answers some of my time away. Anyway, back to the case...
A 32 year old male with a history of HIV, noncompliant with his medications, presents to the ED with a fever, hypoxia, and a cough. CXR is shown below. Given his clinical/medical history, what does this most likely represent, and what lab value might help confirm your diagnosis? What other clinical entity might a CXR like this represent? What is the first line treatment, and what are the indications for steroid therapy in this patient?
This patient likely has Pneumocystis jirovecii pneumonia (formerly PCP pneumonia). This is usually noted by diffuse bilateral infiltrates extending from the hilum on CXR. Having a history of HIV makes this all the more likely. LDH may be helpful in the diagnosis, as levels are usually elevated (> 250) in patients with this disease process. LDH is relatively sensitive, but somewhat nonspecific. Highly elevated levels may indicate worse disease and prognosis. Another prime concern in an immunocompromised patient with a similar CXR would be miliary TB.
The first line therapy is trimethoprim-sulfamethoxazole (TMP-SMX). Alternatively, clindamycin + primaquine can be given in patients who have a contraindication to TMP-SMX. Steroids may be considered as an adjunct therapy that might play a role in decreasing inflammation and respiratory failure. Indications for steroids include a PaO2 < 70 mmHg or an A-a gradient > 35. Don't have an ABG handy? A pulse ox < 92% generally correlates with a PaO2< 70 mm Hg. This is a popular test topic in regards to diseases seen in HIV patients. #EMBoardReview
1. Emergency Medicine: A focused review of the Core Curriculum. pp 241-242.