Module 4: Intra-abdominal infection

what are the criteria involved with HA-IAI

1. Developed longer than 48hr
* after initial source of control
* during current admission to the hospital
* or within preceding 90 days staying in the hospital
* with the past 30 days:
* residence in a skilled nursing or other long-term care facility
* home infusion therapy, home wound care, or dialysis
* during the past 90 days:
* use of broad-spectrum ABx for >= 5 days

What pt **absolute** factors put the pt at high risk for poor outcomes? (4)

APACHE II score > 10

Sepsis or septic shock

Diffuse peritonitis

Delayed or inadequate source control

Conditional risks include? (3)

Age > 70

Current cancer

Major compromise of CV, hepatic, renal function

Which is the most common type of peritonitis?

Secondary by which caused include:

* GI perforation, Post-op, post-traumatic
* vascular causes

Primary: cirrhosis, nephrotic syndrome, peritoneal dialysis

how different in clinical presentation b/w 1st and 2nd peritonitis

* 1st: abdominal tenderness
* normal or mildly elevated temp (fever in 2nd)
* worsening EP (cirrhosis)
* Lab: WBC count normal or mildly elevated
* PMN > 250 cells
* 2nd: increase HR, RR, hypotension, decreased UO
* Lab: WBC 15-20K
* increase in BUN (dehydration)

→ d/x by CT scan

protein level is less than 3g/dL in bacterial peritonitis?

NO, higher than 3

* also pH < 7.35

→ opposite what observe in normal peritoneal fluid since there are no bacteria present

can appendicitis leave untreated?

No

→ can develop complications such as diffuse peritonitis, and severe sepsis since the appendix can burst

What happens in diverticulosis?

formation of pouches (diverticula) in colon wall

* risk increases with age (70% have it by age 80)

most pts are asymptomatic

**Acute bleeding and diverticulitis** are the most two common complications with diverticulosis?

TRUE

* diverticulitis: inflammation, micro-perforation, and abscess formation

should Cefepime and Ceftazidime be used in low-risk CA-IAI?

No

* used for HIGH risk CA
* **use in combination with metronidazole** for anaerobic coverage

what are monotherapy for LOW risk IAI?

1. ertapenem
2. moxifloxacin: reserved due to AE, high risk of causing CDI

* only used for pts with significant reactions to beta-lactam agents

\

what cef can be used in LOW risk

Cefuroxime, ceftriaxone, cefotaxime

Can Pip/taz (Zosyn) use in HIGH risk CA?

Yes

* can also use meropenem
* or imipenem-cilastatin

when aztreonam + vanco can be used?

along with metro

* in pt with severe beta-lac allergies

what additional agents, rather than those in High-risk CA, can be used in HA-IAI?

* Mono: Eravacycline
* Combination: Metro plus
* cefta/avibactam
* Ceftolozance/tazobactam

→ for **pts who are either known or strongly suspected of being infected** with one of the resistant pathogens

which agents be used for empiric anti-enterococcal?

Ampicillin

or Vanco

* If pt is NOT being treated with **pip/taz or imipenem/cilastatin**

for high-risk CA

Are pip/tazo and metronidazole good combination?

NO

* double cover for anaerobes

SAME with mero and metro (no M&M)

ONLY vanco should be used in HA-IAI pts?

Yes

* can consider linezolid or daptomycin if VRE is suspected

(SAME agents for MRSA)

Do we need to give anti-fungal for every pt?

No, just critically ill pts

* 1st line: Fluconazole if C. albicans is isolated
* 2nd line: Echinocandin (micafungin) if C.glabrata present or prior use of Fluconazole

can ampicillin/sulbactam be used empirically?

NO (E.coli resistance)

* avoid clindamycin and Cefoxitin/cefotetan (B. fragilis resistance)
* Amino, FQ due to toxicity problems

how many days should IAI be treated?

4 days

* 14 days for peritonitis from catheter
* 5-7 days for other cases: incomplete source control, incomplete clinical response

who can get shorter therapy for IAI?

treat less than 24 hrs

* Trauma repaired in 12 hrs
* Acute appendicitis w/out perforation, abscess or peritonitis

Oral ABx should be used in short or long-term course of trx?

short-term

* Mono: Moxifloxacin or Augmentin
* Combination: metronidazole plus:
* PO cep: Cephalexin, Cefuroxime, Cefdinir, Cefpodoxime
* FQ: Cipro or Levo

Treatment of SBP in HA?

Pip/taz: 3.375g IV q6h PLUS Vanco IV

* can be used Carbapenems if concerned about ESBL enterobacterales

HA SBP is rare

Should we consider long-term ppx for SBP?

YES

* Bactrim DS PO QD
* OR Cipro 500 mg PO QD

how long should Abx can be used for appendicitis?

24 hours post-op if no complications

in which condition of appendicitis should we consider BROAD-spectrum Abx?

ruptured appendix

* along with other supportive care: rehydration
* need to get the pt for surgery asap

For Diverticulitis, when Abx should be used?

high-risk pts; deferral in low-risk

* based on recent history and pt’s risk of poor outcomes to select appropriate empiric therapy
* Abx can be used ALONE