Chapter 114: Intra-Abdominal Infections

Patient Care Process for Treatment of Complicated Intraabdominal Infection

Collect

Patient characteristics (e.g., age, sex, weight, vital signs, etc.)

• Patient history (past medical, family, social), surgical operations (site, date, procedure), and abdominal imaging findings

• Medication history at hospital admission (include prescription, nonprescription, and other substances) and drug allergies and intolerances. Previous antibiotic use, both inpatient and outpatient, dose and duration.

• Microbiologic results from blood, intraabdominal fluids, and other sources. Susceptibility results when available.

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

Assess

• Determine severity of illness based on vital signs, acute organ dysfunction, source control

• Determine likely pathogens based on type of intraabdominal infection, patient's microbiologic history, previous antibiotic exposure, and response to current therapy. Consider that anaerobic bacteria may be causative agents but may not be isolated in cultures.

• Determine if other conditions are present and likely to affect outcomes.

• Estimate creatinine clearance and adjust drug doses as required.

• Assess drug interactions

Plan

• Determine goals of therapy such as correction of the intra-abdominal disease process and drainage of purulent collections and resolution of infection without major organ system complications.

• Determine appropriate antimicrobial treatment based on severity of illness, likely/confirmed pathogens, local resistance/susceptibility patterns (see Tables 114-6, 114-7, 114-8)

• Establish antimicrobial monitoring goals for efficacy (e.g., resolution of infection, clearance of blood cultures) and drug toxicity.

• Consider other medications that may be needed (e.g., analgesics, medications for nausea and vomiting, thrombosis prevention).

Implement

• Initiate an empiric antimicrobial regimen and establish tentative stop date.

• Deescalate antimicrobial therapy to more narrow-spectrum agents based on response and microbiologic data.

• Assess patient as needed for response to surgical control, medications, and other treatments and discontinue adjunct medications when not needed or indicated.

• Use measures to avoid adverse events to medications and assess for their occurrence.

• Assess pain control and progress of gastrointestinal function.

• Change to oral medications when patient resumes oral feeding.

Follow-up: Monitor and Evaluate

• Monitor signs and symptoms of infection within 2 to 3 days after antimicrobials are initiated and surgical source control is completed. Antimicrobial therapy can typically be discontinued 4-5 days after adequate source control of complicated intraabdominal infections.

• Monitor for emergence of resistant bacterial isolates or Candida spp. in blood or other sources

• Monitor for occurrence of secondary infections such as respiratory and Clostridium difficile

• Upon hospital discharge determine which medications the patient should continue and provide patient education. Discontinue unnecessary medications.

KEY CONCEPTS

• Most 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.

• Primary peritonitis is generally caused by a single organism (Staphylococcus aureus in patients undergoing chronic ambulatory ...