Thread by @virenkaul

Attending "Approach to Management of Pulmonary Infections in Immunocompromised Patients", LIVE right now on the #CHEST2021 platform, a thread🧵

. @kriscrothers: Diagnostic evaluation in patients with HIV include (pic 1)
* Historical elements
* CD4 count
* Chest imaging pattern

Know you infectious and non-infectious processes that can happen with decreasing CD4 counts (see pic 2)

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.@kriscrothers: Compares bacterial pneumonia vs. PCP vs. TB
* > 1 infectious process in 10-20% pts with HIV
* Targeted Rx is key

W/U:
* Expectorated/induced sputum
* Sputum AFB x 3 w/ NAAT in 1 sample
* Bronch: If sputum negative for TB or no sputum for PCP

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@kriscrothers:
* PJP Rx: Bactrim 1st line, steroids improve mortality
* TB: Same as non-IC pts. Daily and observed Rx advised
* Bacterial pneumonia: Same as non-IC pts. However, be aware of risk for MRSA/psuedomonas

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If Rx not working, consider:

* Resistance
* Incorrect diagnosis / 2nd infection
* Noninfectious eg. Lymphoma
* IRIS: Paradoxical or unmasking IRIS
- Common w/ mycobacterial, cryptococcal, viral, KS
- Start ART in 2 wks (delay w/ TB meningitis to 8 weeks

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.@ScottEvansMD: Pulmonary infections in pts. w/ hematological malignancies:

* 10% cancer center adm related to PNA
* Survival depends on pathogen ident + adequate initial Rx

PMID: 28159165

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.@ScottEvansMD:
* PNA leading cause of death post-HSCT (even w/ new diagnosis)
* Hemat malignancy pts ALSO prone to develop uncommon infections eg. invasive aspergillosis

Why? Complicated pathogenesis: IC, malnourishment, mucositis, aspiration (PMID: 28477638)

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.@ScottEvansMD: Pneumonia risk related to degree & duration of neutropenia:
* 15-25% neutropenic pts --> Lung infiltrates
* ANC < 100: infection w/ uncommon org
* Don't forget QUALITATIVE defects in neutrophils even with normal counts eg. with hypoxia or acidosis

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.@ScottEvansMD: Other causes of IC in hemat malignancies:

Ig defects:
Hypogamma, asplenia, CLL, Waldenstrom's, MM, drugs (bortezomib)

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.@ScottEvansMD:
* Identify humora and/or cell mediated IC states
* Pic 1: Common pathogens with cell mediated immunity

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.@ScottEvansMD: Radiological differentials of infiltrates in patients with hemat malignancies. Nice slide!

Also important to identify the correct organism, so Dr. Evans is advocating for early bronchoscopy --> Lesser 100 day mortality in this population.

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.@DrKPennington: Pulmonary infections in pts on immune modulators or biologics:

Know which medications change which part of immune system: T-cell, B-cell, cytokine

This $$ slide shows which organisms are more likely to be involved.

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@DrKPennington: Remember, prophylactic organisms can alter the organisms involved! #CHEST2021