Intra-Abdominal Sepsis

(Includes Diverticulitis and Pilonidal Sinus)

Clinical Features

Causes include appendicitis, biliary tract infection and diverticulitis

Clinical features may include:

• Abdominal pain
• Abdominal distension
• Nausea and vomiting
• Altered bowel habit
• Jaundice
• Fever

Investigations

• Blood culture
• Stool culture and C difficile testing (if diarrhoea present)
• Fluid from newly-inserted drain
• Swabs or fluid from drains in-situ are not typically useful

Infection Control

Consider isolation with contact precautions if the patient has diarrhoea

Treatment

Ensuring cover for Gram negative bacteria is of paramount importance. When Gentamicin stops, ensure alternative antibiotic active against these pathogens is started – Temocillin if empirical (unless allergic to penicillin), or as guided by culture results.

Metronidazole may be given orally (400mg 8 hourly) if the oral route is available

A well patient with mild diverticulitis or pilonidal sinus may be treated entirely with oral therapy

GENTAMICIN IV Dose as per calculator 

PLUS

AMOXICILLIN IV 1g 8 hourly 

PLUS

METRONIDAZOLE PO 400mg 8 hourly

(If oral route is not available, give 500mg 8 hourly IV)

 If true penicillin allergy or if known / suspected MRSA:

VANCOMYCIN IV Dose as per calculator 

PLUS

GENTAMICIN IV Dose as per calculator 

PLUS

METRONIDAZOLE PO 400mg 8 hourly

(If oral route is not available, give 500mg 8 hourly IV)

Do NOT continue Gentamicin beyond 3-4 days. If IV antibiotics are still required after this period, stop Gentamicin and start: TEMOCILLIN IV 2g 8 hourly (discuss patients allergic to penicillin with Microbiology)

IV to Oral switch (IVOS)

If no positive Microbiology and no clear source identified:

COTRIMOXAZOLE PO 960mg 12 hourly 

PLUS

METRONIDAZOLE PO 400mg 8 hourly

If eGFR <35, or intolerant of cotrimoxazole

DOXYCYCLINE PO 100mg 12 hourly 

PLUS

METRONIDAZOLE PO 400mg 8 hourly

Duration: 5-7 days in total (IV + Oral)