Thread by @FilaMentor

1/
First of 2 tweets! #GalactoMagic

50F w/ EtOH cirrhosis & DM presents to ED w/ AMS & decreased UOP. She is febrile & hypotensive

She is started on vasopressors & CVVHD via central lines in the ICU

Due to concern for SBP, she is started on ceftriaxone

2/
Initial blood & ascites cultures show no growth. She remains critically ill for 7 days and still having fevers

In addition to blood cultures, which of the following is the next best test to order?

1/13
Answer: Serum BDG

You have suspicion for invasive candidiasis given the RF of cirrhosis, critical illness in ICU w/ central lines, dialysis, & broad-spectrum antibiotics (see other RF in table)

2/
Others (@gayathri25788 & @fernandbteich) have alluded to crypto being a possibility

Yes, that is very true (hence why it wasn’t listed as an option here)

For a dive into cryptococcosis & cirrhosis, please review this question and thread

https://twitter.com/FilaMentor/status/1361726736078004224?s=20

3/
Fungal blood cx are rarely indicated

Providers should focus on collecting adequate # of standard blood culture bottles (2) & blood volume (5-10cc/bottle)

Fungal blood cx may be used for suspected disseminated infection from:
🌞Blasto
🌞Cocci
🌞Histo
🌞Malassezia (RF: TPN)

4/
For some great thoughts on fungal blood cultures, please see tweets from:

@KatesOlivia

https://twitter.com/KatesOlivia/status/1372591680918974467?s=20

&

@IdVilchez

https://twitter.com/IdVilchez/status/1372595402797506562?s=20

5/
In diagnosing invasive candidiasis, there are 3 entities that we consider:

⚡️Group 1- candidemia without deep-seated candidiasis

⚡️Group 2- candidemia with deep-seated candidiasis

⚡️Group 3- deep-seated candidiasis without candidemia

6/
In studies of autopsy-proven invasive candidiasis, sens of blood cx ranged from 21-71%

This range applies to pts who were likely candidemic at some point

Patients in Group 2 were likely candidemic at one time, but may not have been candidemic at the time blood cx were drawn

7/
If we look at just Group 1 (candidemia w/o deep-seated), sensitivity increases to 63-83%!

🌑Below is a summary of autopsy-proven invasive candidiasis

pubmed.ncbi.nlm.nih.gov/23315320/

8/
Now, shifting to candidemia...

The median time to blood culture positivity is 2-3 days (perhaps better than the turnaround time for BDG at some hospitals)

We have to think about the RFs in Tweet 1 in trying to identify candidemia, especially if a patient is not improving

9/
Why is identifying candidemia important?

Retrospective study across 4 sites looked at 230 pts w/ candidemia & time to fluconazole start

At Day 0, mortality was 15%

⭐️For each day of treatment delay, you have ⬆️mortality (more than doubles by Day 2)

pubmed.ncbi.nlm.nih.gov/16758414/

10/
What about BDG testing for invasive candidiasis in the ICU?

💫BDG and Candida studies differ with respect to patient population, risk factors, & timing of BDG testing

⭐️Generally, they suggest a NPV > 90% & PPV < 70%

academic.oup.com/cid/article/72…

11/
Since NPV is high, a negative BDG can be used to hold or d/c antifungals

+BDG prompting antifungals is less clear 2/2 lower PPV, but can be helpful in high-risk pts
(abd surgery, GI perf, hepatobiliary anastomotic leakage; necrotizing pancreatitis)

academic.oup.com/cid/article/72…

12/
A group from European Organization for Research & Treatment of Cancer & Mycoses Study Group Education & Research Consortium (EORTC/MSGERC) reviewed the updated fungal guidelines, specifically looking at BDG

In red is the BDG rec for Candida in ICU

academic.oup.com/cid/article/72…

13/
Due to "limited sens & spec, utility of serum BDG differs by pt population at risk of IFI"

"Prevalence of IFI in specific populations & pre-test probability of IFI in pts should be taken into account when interpreting negative & positive results"

academic.oup.com/cid/article/72…