Skip to Main Content



  • imageMost intra-abdominal infections are “secondary” infections that are polymicrobial and are caused by a defect in the gastrointestinal (GI) tract that must be treated by surgical drainage, resection, and/or repair.

  • imagePrimary peritonitis is generally caused by a single organism (Staphylococcus aureus in patients undergoing chronic ambulatory peritoneal dialysis [CAPD] or Escherichia coli in patients with cirrhosis).

  • imageSecondary intra-abdominal infections are usually caused by a mixture of bacteria, including enteric gram-negative bacilli and anaerobes, which enhance the pathogenic potential of the bacteria.

  • imageFor peritonitis, early and effective IV fluid resuscitation and electrolyte replacement therapy are essential. A common cause of early death is tissue hypoperfusion precipitated by inadequate intravascular volume.

  • imageTreatment is generally initiated on a “presumptive” or empirical basis and should be based on the likely pathogen(s), local resistance patterns, and severity of illness.

  • imageAntimicrobial regimens for secondary intra-abdominal infections should include coverage for enteric gram-negative bacilli and anaerobes. Antimicrobials that may be used for the treatment of secondary intra-abdominal infections depending on severity of illness and microbiology data include: (a) third-generation cephalosporin (ceftriaxone) with metronidazole, (b) piperacillin–tazobactam, (c) a carbapenem (imipenem, meropenem, doripenem, or ertapenem), or (d) a quinolone (levofloxacin or ciprofloxacin) plus metronidazole or moxifloxacin alone.

  • imageTreatment of patients with peritoneal dialysis-associated peritonitis should include an antistaphylococcal antimicrobial such as a first-generation cephalosporin (cefazolin) or vancomycin as well as an agent with significant gram-negative activity such as a third-generation cephalosporin or aminoglycoside; intraperitoneal administration is preferred.

  • imageThe duration of antimicrobial treatment should be 4 days after achievement of source control for most secondary intra-abdominal infections.

  • imagePatients treated for intra-abdominal infections should be assessed for the occurrence of drug-related adverse effects, particularly hypersensitivity reactions (β-lactam antimicrobials), diarrhea (most agents), fungal infections (most agents), and nephrotoxicity (aminoglycosides).


Patient Care Process for Treatment of Intra-Abdominal Infections



  • Patient characteristics (eg, age, sex, weight, body mass index)

  • Patient history (past medical, family, social—dietary habits, tobacco use, alcohol use, substance abuse) and surgical operations (site, date, procedure)

  • Medication history at hospital admission (prescription and non-non-prescription medications and supplements), drug allergies, and intolerances; previous antibiotic use, inpatient and outpatient, dose and duration

  • Microbiologic results from blood, intra-abdominal fluids, and other sources, and obtain susceptibility results when they are available

  • Laboratory results for infection, major organ function (particularly kidney and liver), and immune status


  • Hemodynamic status (eg, MAP, HR)

  • Estimate creatinine clearance for drug dosing

  • Review all culture results and consider anaerobic bacteria may be causative agents but may not be isolated in cultures


  • Determine initial empiric treatment and monitoring plan

  • Establish antimicrobial monitoring goals for microbiologic and clinical outcomes

  • Consider other medications that may be needed during treatment or post-surgery (ie, analgesics, medications for nausea and vomiting, thrombosis prevention)

  • Check for drug interactions and dose adjustments based on end-organ function


  • Initiate an empiric antimicrobial regimen and continue until microbiologic data is available and establish tentative stop date

  • De-escalate ...

Pop-up div Successfully Displayed

This div only appears when the trigger link is hovered over. Otherwise it is hidden from view.