IAI Flashcards
Types of Intra-abdominal Infections
Primary Peritonitis (2)
1) Peritoneal Dialysis Related Peritonitis
2) Spontaneous Bacterial Peritonitis
Types of Intra-abdominal Infections
Secondary Peritonitis (6)
1) Diverticulitis
2) Appendicitis
3) Cholecystitis
4) Intra-abdominal Abscess
5) Cholangitis
6) Necrotizing Pancreatitis
Intra-abdominal Infections – Definitions
___ infection - Confined to organ, does not extend
___ infection
- Extends beyond a single organ into the peritoneal space and associated with peritonitis
Community-acquired infection
- Occurs within 48 hours of hospital admission, no healthcare exposure
- Caused by ___ intra-abdominal flora
Healthcare-associated infection
- Occurs after 48 hours of hospital admission
- Healthcare exposure in last 12 months (e.g., hospitalization, recent surgery)
- uncomplicated
- complicated
- normal
Spontaneous Bacterial Peritonitis (SBP)
No obvious source of bacterial ___
Patients at highest risk
- ___ failure and ascites – alcoholic cirrhosis
- ___ ambulatory peritoneal dialysis (CAPD)
Most commonly monomicrobial
- ___ and other Enterobacterales (e.g., K. pneumoniae)
- Streptococci
- Enterococci
- Staphylococcus aureus and coagulase negative staphylococci (more common with ___ )
- contamination
- hepatic
- continuous
- E. coli
- CAPD
SBP – Clinical Presentation and Diagnosis
Clinical presentation
- Abdominal pain
- Nausea, vomiting, diarrhea
- Fevers, chills
- Reduced/absent bowel sounds
- Altered mental status/encephalopathy
Diagnosis
- Signs and symptoms of infection
- Ascitic fluid analysis
- Low ascitic fluid protein (< 2.5 g/dL)
- Absolute neutrophil count > ___ /mm3
TNC x bands
250
SBP – Recommended Treatment Options
Empiric
- ___ 1-2 g IV Q24H
- Cefepime 1 g IV Q8H*
- Piperacillin/tazobactam 3.375 g IV Q6-8H*
- Meropenem 1 g IV Q8H*
S. aureus/Coagulase negative staphylococci (Risk for MRSA)
- ___ (dosing based on PK eval)
- Linezolid 600 mg IV/PO Q12H
- Daptomycin 6-12 mg/kg IV Q24H
Anaerobic coverage
- Beta-lactam/beta-lactamase inhibitor
- Carbapenem
- Add ___ (e.g., ceftriaxone, cefepime)
(*) = consider extended infusion dosing regimen
- ceftriaxone
- vanc
- metronidazole
SBP – Treatment Duration
SBP in patient with cirrhosis and ascites
- __ - __ days
- Secondary prophylaxis recommended after treatment completed
⎻ Example options – TMP/SMX DS PO once daily or ciprofloxacin 500 mg PO once daily
Peritonitis in patient undergoing CAPD
- ___ - ___ days
- Intraperitoneal administration of antibiotic(s) preferred
- 5-7
- 14-21
Secondary Peritonitis
probably going to be ___
- Staphylococcus aureus and Pseudomonas aeruginosa possible, but less common
- ___ is most common
- polymicrobial
- E. coli
What makes intra-abdominal infections unique?
___ organ systems affected
- GI tract – bowel paralysis → abdominal distention
- Cardiovascular – fluid shifts → hypotension, tachycardia, vasoconstriction
- Respiratory – hypoxemia
- Renal – decreased renal perfusion → renal failure
Bacterial ___
- Enterobacterales (e.g., E. coli) create optimal environment for ___ bacteria
- Anaerobes cause ___ formation and have several virulence factors
Multiple
Synergy
- anaerobic
- abscess
Intra-abdominal Infections – Treatment Considerations
1) Source Control
- Repair perforations
- Resection of infected organs/tissue
- Removal of foreign material
- Drain purulent collections
- Important to obtain ___
2) Antimicrobial Therapy
- look at antibiogram (dont use is resistance 10-20%)
- consider if ___ or ___coverage is necessary
- culture
- enterococci, fungal
Intra-abdominal Infections – Empiric Antibiotic Regimens
T or F: Ampicillin/sulbactam not recommended empirically due to E. coli resistance
TRUE
Intra-abdominal Infections – Empiric Antibiotic Regimens
Community-acquired Mild-moderate severity
- ___ 1-2 g IV Q24H + ___ 500 mg IV/PO Q8-12H
- Cefazolin 2 g IV Q8H + Metronidazole 500 mg IV/PO Q8-12H
- Ciprofloxacin 400 mg IV Q8-12H + Metronidazole 500 mg IV/PO Q8-12H
- Levofloxacin 750 mg IV Q24H + Metronidazole 500 mg IV/PO Q8-12H
- Cefoxitin 2 g IV Q6H
- Ertapenem 1 g IV Q24H
- Tigecycline 50 mg IV Q12h
- ceftriaxone, metronidazole
Intra-abdominal Infections – Empiric Antibiotic Regimens
Community-acquired
High severity and Healthcare-associated
- ___ 3.375-4.5 g IV Q6H
- Meropenem 1 g IV Q8H
- ___ 1-2 g IV Q8H + Metronidazole 500 mg IV/PO Q8-12H
- Ciprofloxacin 400 mg IV Q8-12H + Metronidazole 500 mg IV/PO Q8-12H
- Levofloxacin 750 mg IV Q24H +
- Metronidazole 500 mg IV/PO Q8-12H
Candida albicans on culture
- ___
Candida species other than Candida albicans on culture
- ___
- Piperacillin/tazobactam
- cefepime
- Fluconazole
- Micafungin
T or F: Common to maintain anaerobic coverage even if culture does not isolate anaerobic bacteria
TRUE
- difficult to isolate, keep coverage just in case
Intra-abdominal Infections – Oral Antibiotic Regimens
Generally, acceptable to transition to oral antibiotic regimen once clinical stability is
achieved
Common oral antibiotic regimens
- ___ 875/125 mg PO Q __ -12H
- ___ 400 mg PO Q12H + Metronidazole 500 mg PO Q8-12H
- Cephalexin 1000 mg PO Q6H + Metronidazole 500 mg PO Q8-12H
- Cefadroxil 1000 mg PO Q12H + Metronidazole 500 mg PO Q8-12H
- Ciprofloxacin 500-750 mg PO Q12H + Metronidazole 500 mg PO Q8-12H
- Levofloxacin 750 mg PO Q24H + Metronidazole 500 mg PO Q8-12H
- TMP/SMX DS 1-2 tabs PO Q12H + Metronidazole 500 mg PO Q8-12H
if possible, confirm susceptibility
- Amoxicillin/clavulanate, 8
- Cefpodoxime
Intra-abdominal Infections – Treatment Duration
Difficult to determine when source controlled is achieved in complicated infections
general: __ - __ days after source control
Diverticulitis:
- uncomplicated: Abx not needed
- moderate/severe: __ - __ days
Appendicitis without perforation, abscess, or peritonitis, Cholecystitis without
perforation, and Bowel injuries repaired within 12 hours: ___ hrs
- 4-7
- 5-10
- 24
