Thread by @FilaMentor

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First of 2 tweets! #GalactoMagic

65F presents w/ 8 days of SOB. T 38C, HR 115, BP 100/60, RR 22, O2 92% on 100% non-rebreather & then intubated

Exam notable for crackles. CT chest shows GGO bilaterally

She has a +SARSCoV2 NAT resp swab; sputum & blood cultures are negative

2/
After remdesivir, dexamethasone, ceftriaxone & doxy, she defervesces. 3 weeks later, she has worsening SOB

Repeat CT chest shows worsening GGO & new pulm nodules

Which of the following is the most sensitive diagnostic modality for COVID-19 associated pulmonary aspergillosis?

1/11
Answer: BAL fluid culture

Although the most feasible test would be a tracheal aspirate culture, the highest yield test for Aspergillus is the BAL fluid culture

🌞Serum GM and BDG lack sensitivity compared to BAL testing

2/
COVID-19 associated pulmonary aspergillosis (CAPA) can be hard to diagnose b/c of:
⭐️difficulty in differentiation b/w colonization & true pathogen
⭐️differences in definitions
⭐️limited sensitivity of serum fungal tests
⭐️varying bronch rates

pubmed.ncbi.nlm.nih.gov/32887998/

3/
CAPA is an entity seen in pts that are critically ill in the ICU

Usually, it’s diagnosed when:
⚡️resp status worsens despite ARDS mgmt & ruling out other causes
⚡️new, persistent, or rising fever while ruling out other causes
⚡️progressive infiltrates, new nodules/cavitation

4/
Why is it important to diagnose CAPA?

Several studies have shown excess mortality rates of 16-25% compared w/ pts without evidence for aspergillosis

CAPA is mostly considered an invasive form of aspergillosis, but can sometimes be disease in airway

pubmed.ncbi.nlm.nih.gov/33333012/

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Additionally, people w/ CAPA:
🌑had worse outcomes
🌑had longer time to improvement
🌑were intubated twice as long as those without CAPA
🌑had longer hospital length of stay

pubmed.ncbi.nlm.nih.gov/33693551/

6/
Overall, diagnostic modalities include:
💫Biopsy of lungs with histopath
💫Tracheal aspirates
💫BAL culture
💫Aspergillus PCR from BAL
💫Serum galactomannan (GM)
💫BAL galactomannan
💫Serum beta-d-glucan

7/
We try to diagnose w/ sputum culture, but sensitivity in ICU pts for Invasive Pulmonary Aspergillosis (IPA) does not exceed 50%

We have previously reviewed the test characteristics of both serum & BAL GM in ICU patients

https://twitter.com/FilaMentor/status/1362817638292852738?s=20

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The ICU Working Group from the EORTC/MSGERC worked on IPA definitions in the ICU

They did not reach a high level of certainty w/ definitions 2/2 heterogeneity of predisposing factors & uncertainty about the true prevalence of IPA in the ICU

pubmed.ncbi.nlm.nih.gov/33709127/

9/
Workgroup definition for probable IPA includes one from each category:
1⃣myco evidence
🍋culture in lower resp tract
🍋serum GM >0.5
🍋BAL GM >0.8

2⃣
🍊at least 1 clinical/radiologic abnormality c/w an unexplained infection (see image)

3⃣
🍎at least 1 host factor (see image)

10/
For CAPA, there are definitions proposed by @KoehlerPh & others

Since its publication, there's been a fantastic exchange of letters regarding the diagnostic dilemma of CAPA

pubmed.ncbi.nlm.nih.gov/33333012/

Letter 1- pubmed.ncbi.nlm.nih.gov/33662327/

Letter 2- pubmed.ncbi.nlm.nih.gov/33662323/

11/
CAPA is broken down into:
⚾️proven
⚾️probable
⚾️possible

🥎Within probable & possible, imaging & clinical factors are the same

🎾The differences lie in the micro evidence for aspergillosis, particularly with GM cut-offs (which are discussed in the letters above)

Thank you so much for following along!