Intra-Abdominal Infections Flashcards
What are the examples of primary peritonitis?
-Spontaneous bacterial peritonitis (SBP)
-Peritoneal dialysis related peritonitis
Examples of secondary peritonitis
-Diverticulitis
-Appendicitis
-Cholecystitis
-Intra-abdominal abscess
Definition of an uncomplicated infection
-Confined within the visceral space
-Does not extend into peritoneum
Definition of a complicated infection
Extends beyond a single organ into the peritoneal space and is associated with peritonitis
SBP definition
-No obvious source of bacterial contamination
-Most commonly monomicrobial
Patients at highest risk of SBP
-Hepatic failure and ascites - alcoholic cirrhosis
-Continuous ambulatory peritoneal dialysis
Most common bacteria to infect SBP
E. Coli
How do you diagnose SBP?
-Ascitic fluid analysis
-ANC over 250
How do you calculate ANC in an ascitic fluid analysis?
TNC x % neutrophil
SBP treatment options for empiric selection
-Ceftriaxone (DOC)
-Cefepime (used for resistant gram negative)
-Zosyn (used for resistant gram negative)
-Meropenem (used for resistant gram negative)
What agent what you add to SBP treatment if you are concerned for MRSA?
-Vancomycin
-Linezolid
-Daptomycin
What agents would you add to SBP treatment if you need to cover anaerobes?
-Beta-lactam/beta-lactamase inhibitor
-Carbapenem
-Add metronidazole to empiric therapy
When would secondary prophylaxis be recommended after treatment of SBP?
In patients with cirrhosis and ascites
What are the treatment options for secondary prophylaxis for SBP?
-Bactrim
-Ciprofloxacin
How long would you give secondary prophylaxis for SBP?
Indefinitely
What is the duration of treatment for SBP in patients with cirrhosis and ascites?
5-7 days
What would the duration of treatment be for patients who have peritonitis due to dialysis?
14-21 days
What is the most common pathogen in secondary peritonitis?
E. Coli
Is secondary peritonitis monomicrobial or polymicrobial?
Polymicrobial
What is bacterial synergy?
When aerobic bacteria consumes all of the oxygen in an environment, allowing for anaerobic bacteria to flourish, causing a polymicrobial infection
How would you diagnose secondary peritonitis?
-Look for signs and symptoms of sepsis (tachypnea, tachycardia, hypotension, etc.)
-Imaging such as CT scan or X-ray
What are the two main methods of treatment for intra-abdominal infections?
-Source control
-Antimicrobial therapy
Examples of source control procedures
-Repair perforations
-Resection of infected organs and tissue
-Removal of foreign material
-Drain purulent collections
-IMPORTANT TO OBTAIN CULTURES
Three important points for empiric antibiotic selection for secondary peritonitis
-Look at local antibiogram so you can select agents with the highest likelihood to cover common organisms
-Cover enterococci if necessary
-Provide antifungal coverage if necessary
When is it necessary to cover for enterococci in secondary peritonitis?
-High severity IAI
-History of recent cephalosporin use
-Immunocompromised
-Biliary source of infection
-History of valvular heart disease
-Prosthetic intravascular material
When is it necessary to cover for fungi in secondary peritonitis?
-If isolated in culture
-Consider if not patient not improving on antibiotic therapy
-Consider with esophageal perforation
Which agents cover enterococci?
-Zosyn
-Meropenem
Why is Unasyn not recommended for empiric treatment of secondary peritonitis?
High prevalence of E. Coli resistance to Unasyn
What can be used to treat Candida albicans when it is found on culture?
Fluconazole
What can be used to treat Candida species other than albicans when it is found on culture?
Micafungin
Which antibiotics should NEVER be used in the treatment of IAIs?
FQs
When should you cover for anaerobes in secondary peritonitis?
Always
What is the preferred oral antibiotic for IAIs?
Augmentin Q8-12H
Secondary peritonitis general treatment duration
4-7 days after source control
Diverticulitis treatment duration
-Uncomplicated - antibiotic not needed
-Moderate/severe - 5-10 days
Appendicitis without perforation, abscess, or peritonitis treatment duration
24 hours
Cholecystitis without perforation treatment duration
24 hours
Treatment duration for bowel injuries repaired within 12 hours
24 hours
