How do you balance diagnostic stewardship and high value cost-conscious care when working up a patient with newly diagnosed HIV/AIDS admitted to the ICU with shortness of breath who most likely has PJP pneumonia or cryptococcal infection but is at risk of multiple other pathogens? 

Multiple concurrent OIs are common in individuals with advanced HIV and contribute significantly to morbidity. Because several infections can emerge simultaneously in the setting of profound immunosuppression, recognizing the likelihood of multiple coexisting pathogens is critical. Early identification of these infections is clinically impactful and cost‑effective, as timely treatment can prevent severe complications, hospitalizations, and the need for more intensive care later.

Guideline‑based screening offers a streamlined and economical approach by tailoring testing to the degree of immunosuppression. For example, in endemic areas, screening for histoplasmosis or coccidioidomycosis at specific CD4 thresholds is inexpensive yet can avert ...

This is an excellent question, which is very based on the patient's clinical presentation as well as the resources you have available to you in your setting, particularly how long it takes for test results to come back. One aspect that should be considered in patients with advanced HIV is that they can have more than one infection at a time, and it's important not to anchor on one diagnosis when you get a positive result. The differential diagnosis can be very broad when CD4 counts are very low.

The clinical presentation and radiology can be very useful in helping determine the correct tests to order; a more acute presentation (within hours/days) may not require extensive diagnostic evaluation, whereas a more chronic presentation can take m...