1/
75M with ESRD on continuous ambulatory peritoneal dialysis admitted with 1 wk of abd pain and cloudy PD effluent
VS stable
WBC 5k, 78%N
Effluent: WBC 1537, LDH 55, Glc 20

Empiric tx choice?

#MedTwitter #IDTwitter #NephTwitter

2/
Today’s #tweetorial = PERITONITIS, which can include several different types:
Primary
Secondary
Tertiary
PD-associated

We’ll focus on SBP and PD-associated peritonitis mostly today!

3/
For primary peritonitis, think of spontaneous bacterial peritonitis (SBP) in a pt with liver cirrhosis, ascites

Clinical presentation = acute illness with fever, abd pain. May have altered mental status and hypotension as well.

Other pathogens (eg TB) rare, more indolent

4/
SBP is typically caused by enteric GNRs. Other orgs are less common without risk factors

We won’t dive into secondary/tertiary peritonitis much here, but key : these infections are typically polymicrobial, often due to break in intra-abd mucosa (abd abscess, perf viscus)

5/
How dx peritonitis: Paracentesis

Interpreting ascites fluid is vital. See summary chart for results you would expect with diff types of peritonitis

SBP criteria and the 250 PMN cutoff is a common #TipsForNewDocs! #MedTwitter #GITwitter #medstudenttwitter

6/
Notice PD-associated peritonitis has diff dx criteria though: WBC >100 or >50% PMNs (if short dwell, may consider >50% PMNs abnormal even with WBC <100)

May also have different clinical features:
Abd pain
Cloudy effluent/dialysate
Bacteremia+fever less common than SBP

7/
PD-associated inf can be: intraluminal contamination (connect/disconnect cath for exchange), exit site/tunnel infection, visceral (bowel bact)

Micro reflects this as pathogens often gram positive (bacterial skin contaminant). See chart/ref below
https://pubmed.ncbi.nlm.nih.gov/17080112/ 

8/
On to management, details
Why 5d? Here is RCT that comp'd 5 v 10d of cefotax in SBPboth grps similar cure, recurrent inf, mort https://pubmed.ncbi.nlm.nih.gov/2019378/ 

Many ctrs have diff approach to f/u paras, good topic to discuss with your GI colleagues @BIDMC_GI @javiervg0902

9/
Management of PD-assoc'd peritonitis is different.

Did you know that there are ISPD guidelines?
For catheter inf: https://journals.sagepub.com/doi/pdf/10.3747/pdi.2016.00120
For peritonitis:
https://journals.sagepub.com/doi/pdf/10.3747/pdi.2016.00078

10/
Despite guidelines, theres variability. Here is a chart w/recs for tx by org + dosing charts

This is just part of the management though, #NephTwitter likely has other tips. Shout-out to @BID_NephFellows for their expertise + #PharmTwitter friends to help w/IP abx dosing!

11/
Lastly, what are indications for PD catheter removal?
Refractory perit
Relapsing perit
Refractory catheter inf
Fungal peritonitis

Strongly consider with:
Mycobact or polymicrobial inf
Association with intra-abd pathology

12/
PD-assoc'd peritonitis is more complex than fits in this thread, a recent publ thinking about management: https://www.sciencedirect.com/science/article/pii/S2590059520301321

Here's case/review fr initial poll. Don't forget pet-associated PD-peritonitis if you have an unusual bug! https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7081570/