Duration of therapy for peritonitis due to perforated viscus

For peritonitis due to perforated viscus, the total duration of therapy (intravenous + oral) is usually 4 days after adequate source control has been achievedSawyer, 2015.

For patients who remain critically unwell (ie requiring intensive care support) after surgical source control, a total duration of up to 7 days (intravenous + oral) may be usedBalance Investigators, 2024Montravers, 2018. For patients who do not improve after 7 days of antibiotic therapy, consider causes of treatment failure, including residual undrained intra-abdominal collections or abscesses.

Patients with residual undrained intra-abdominal collections or abscesses often require a longer duration of therapy (up to 4 to 6 weeks depending on clinical and radiological progress). For the appropriateness of intravenous to oral switch and duration of therapy, seek expert advice. Ambulatory antimicrobial therapy may be appropriate for patients requiring a longer duration of intravenous therapy.