IAIs

Question 1

Primary Peritonitis

Answer 1

Usually monomicrobial (mainly aerobic)
Integrity of GI tract still intact
Typically seen in pts with cirrhosis or peritoneal dialysis catheter
May develop over days to weeks
Can usually be managed by antibiotics alone

Question 2

Common Pathogens Causing Primary Peritonitis

Answer 2

E. coli - most common
Strep - most common gram-positive
Mostly aerobic

Question 3

First-Line Treatment of Primary Peritonitis

Answer 3

2nd or 3rd gen ceph (cefoxitin, cefotetan, cefuroxime, ceftriaxone)
Want to cover GNR + Strep

Question 4

Treatment of Primary Peritonitis if Anaerobes Suspected

Answer 4

Add clindamycin or metronidazole

Question 5

Treatment of Primary Peritonitis if PCN/CEPH Allergy

Answer 5

Vancomycin + aztreonam
Alternatives: Tigecycline, eravacycline

Question 6

Additional Treatment Regimens for Primary Peritonitis

Answer 6

Aminoglycoside + ampicillin or pen G (effective, but increased risk of nephrotoxicity and ototoxicity)
Fluoroquinolone (cipro or levo) - last-line due to increasing resistance (RESERVE for Pseudomonas)

Question 7

Duration of Therapy for Primary Peritonitis

Answer 7

10-14 days

Question 8

Secondary Peritonitis

Answer 8

Usually polymicrobial (aerobic and anaerobic)
Loss of GI integrity
Pts usually in acute distress
Usually requires surgery + antibiotics

Question 9

Common Pathogens Causing Secondary Peritonitis

Answer 9

E. coli - most common aerobe
B. frag - most common anaerobe
Usually combination of aerobes + anaerobes

Question 10

Empiric Therapy for Secondary Peritonitis

Answer 10

Many treatment regimens possible, just need coverage for enteric GNRs and anaerobes

3rd Gen Ceph + Metronidazole
Zosyn +/- Aminoglycoside
Ertapenem

Question 11

Empiric Therapy for Secondary Peritonitis if PCN Allergy

Answer 11

Aztreonam + Metronidazole + Gm + Coverage
Tigecycline (no Pseudomonas coverage)

Question 12

Antibiotics NOT Recommended for Secondary Peritonitis

Answer 12

Ampicillin/sulbactam
Cefotetan, cefoxitin, clindamycin

Question 13

When is empiric anti-enterococcal coverage needed for secondary peritonitis?

Answer 13

Post-op infection
Received prior ceph therapy
Immunocompromised
Have valvular heart disease or prosthetic intravascular materials

Question 14

Empiric Anti-Entercoccal Therapy for Secondary Peritonitis

Answer 14

Ampicillin
Zosyn
Vanco

Question 15

When is empiric anti-MRSA coverage needed for secondary peritonitis?

Answer 15

Known colonizer
Prior treatment failure and significant antibiotic exposure

Question 16

Empiric Anti-MRSA Therapy for Secondary Peritonitis

Answer 16

Vanco

Question 17

When is antifungal coverage needed for secondary peritonitis?

Answer 17

Severe-community acquired
Healthcare-associated
Neonates

Question 18

Empiric Antifungal Therapy for Secondary Peritonitis

Answer 18

Fluconazole
If critically ill → echinocandin

Question 19

Duration of Therapy for Secondary Peritonitis

Answer 19

4-7 days

Question 20

Common Pathogens of Intra-Abdominal Abscess

Answer 20

Usually polymicrobial (mostly anaerobes)

Aerobes: PEK

Anaerobes: B. frag

Question 21

Treatment of Intra-Abdominal Abscess

Answer 21

Surgery + Antibiotics (antibiotic regimens similar to secondary peritonitis)