Intra-abdominal Infections Flashcards
What are the two categories of intra-abdominal infections?
- Primary peritonitis
- Secondary peritonitis
List the various types of primary peritonitis:
- peritoneal dialysis related peritonitis
- spontaneous bacterial peritonitis (SBP)
List the types of secondary peritonitis:
- appendicitis
- cholangitis
- cholecystitis
- diverticulitis
- intra-abdominal abscess
- necrotizing pancreatitis
What patient population is at highest risk for spontaneous bacterial peritonitis?
Patients experiencing hepatic failure and ascites from alcoholic cirrhosis are at the highest risk for SBP.
This is because these patients are somewhat immunocompromised since their liver doesn’t work properly.
How does a patient with spontaneous bacterial peritonitis (SBP) present?
- abdominal pain
- N/V/D
- fever, chills
- reduced or absent bowel sounds
- altered mental status/encephalopathy
How is SBP diagnosed?
- absolute neutrophil count > 250
- low ascitic fluid protein
- signs and symptoms of infection
Calculate ANC by multiplying TNC by bands/neutrophils percentage
What are the common pathogens for SBP?
E. coli
staph aureus is common in patients with CAPD
Is SBP typically monomicrobial or polymicrobial?
monomicrobial
What are the empiric treatment options for SBP?
Empirically cover e. coli and other GN
- ceftriaxone IV Q24H
- cefepime
- pip/tazo
- meropenem
What is the treatment duration for SBP in a patient with cirrhosis and ascites?
5-7 days
secondary prophylaxis is recommended after initial tx is complete (bactrim or cipro PO QD)
What is the duration of treatment for peritonitis in a patient undergoing CAPD?
14-21 days
intraperitoneal administration of abx preferred
Which agents should be added on to SBP treatment if cultures show staph aureus/coagulase negative staphylococci?
Risk for MRSA
- vancomycin
- linezolid
- daptomycin
One of these agents would get added onto their ceftriaxone (or other empiric option)
When is anaerobic coverage needed for SBP?
- Not common
- can add coverage if they have history
What are the most common pathogens for secondary peritonitis?
- E. coli
- Bacteroides fragilis (if anaerobic)
Other common pathogens for secondary peritonitis include: klebsiella, enterobacter, strep viridans, enterococcus
Is secondary peritonitis monomicrobial or polymicrobial?
polymicrobial
How does secondary peritonitis present?
- abdominal pain and distention
- nausea and vomiting
- fever +/- chills
- loss of appetite
- inability to pass flatus and/or feces
- tachypnea, tachycardia
- hypotension
- significant abdominal tenderness
- rigidity of abdominal wall
- reduced or absent bowl sounds
How is secondary peritonitis diagnosed?
signs and symptoms of IAI + imaging
IAI = intra-abdominal infection
imaging is either CT scan or X-ray
What are the pillars of treatment for intra-abdominal infections?
- source control
- antimicrobial therapy
Examples of source control include: repairing perforations, resecting infected organs/tissue, removing foreign material, or draining purulent collections (important for cultures)
What are the three considerations when picking empiric therapy for intra-abdominal infections?
- Select agent or combination that will cover most common organisms (e. coli)
- Consider if enterococci coverage is necessary
- consider if antifungal coverage is necessary
When is enterococci coverage necessary for intra-abdominal infections?
- high severity IAI
- hx of recent cephalosporin use
- immunocompromised
- biliary source of infection
- hx of valvular heart disease
- prosthetic intravascular material
Enterococci coverage is not necessary for mild-moderate community-acquired IAI
When is antifungal coverage necessary for intra-abdominal infections?
- only add if isolated in culture
- may consider if patient is not improving on appropriate antibiotic therapy
- may consider with esophageal perforation
What differentiates between an uncomplicated infection versus a complicated infection?
- Uncomplicated infections are confined within visceral structure (one organ) and does not extend into peritoneum.
- Complicated infections extend beyond a single organ into the peritoneal space and are associated with peritonitis.
What are potential regimens for CA mild-moderate IAI?
- ceftriaxone + metronidazole
- cefazolin + metronidazole
- cefoxitin
- ertapenem
- tigecycline
What are potential regimens for CA high-severity or healthcare associated IAI?
- pip/tazo
- meropenem
- cefepime + metronidazole
What drug is added if candida albicans is on the culture?
fluconazole
Add micafungin if it is any other candida species other than albicans
What are common oral regimens to step-down to once clinical stability is achieved for IAI?
- amox/clav 875/125 PO Q8H
- cefpodoxime + metronidazole
What is the general treatment duration for IAI?
4-7 days after source control
What is the treatment duration for diverticulitis?
- If uncomplicated –> no abx
- if moderate/severe –> 5-10 days
What is the duration of treatment for:
- appendicitis w/o perforation, abscess, or peritonitis
- cholecystitis w/o perforation
- bowel injuries repaired w/in 12 hours
24 hours
