Intra-abdominal Infections

General Points

•     Review previous microbiology results for resistant Gram negative bacteria or Multi-Drug Resistant Organisms (MDROs) e.g. ESBL-producers, CPE, and Vancomycin Resistant Enterococcus (VRE).

•     If history of MDRO or VRE discuss patient with Clinical Microbiology.

•     Consider fungal infection, see below.

•     Send blood cultures, pus, fluid and/or tissue from surgical procedure for culture.

•     Source control (surgical intervention and/or percutaneous drainage) is critical to the management of intra-abdominal infections other than SBP.

Source: WSES/GAIS/SIS-E/WSIS/AAST global clinical pathways for patients with intra-abdominal infections 2021

Mild Community Acquired Infection (Empiric therapy)

Co-amoxiclav 1.2g TDS IV +/- Gentamicin once daily IV (Please see Gentamicin dosing schedule).

Penicillin allergy

NOT IgE -mediated /anaphylaxis / severe reaction:

Cefuroxime 1.5g TDS IV and Metronidazole 500mg TDS IV/ 400mg TDS PO +/- Gentamicin once daily IV (Please see Gentamicin dosing schedule ).

IgE-mediated/anaphylaxis/severe reaction:

Ciprofloxacin* 400mg BD IV/ 500mg-750mg BD PO and Metronidazole 500mg TDS IV/ 400mg TDS PO +/- Gentamicin once daily IV (Please see Gentamicin dosing schedule ).

• Review need for Gentamicin daily. The use of Gentamicin in combination with other agents (e.g. co-amoxiclav) is rarely required for longer than 3 days. Discuss with clinical microbiology if required.
• If history of infection or colonisation with MRSA consider the addition of Vancomycin or Teicoplanin to the above combinations. (Please see Vancomycin / Teicoplanin dosing schedule).

* Please read the HPRA Drug Safety Alert issued in 2018 and the HPRA Drug Safety Newsletter issued in 2023 highlighting restrictions on use of fluoroquinolones (eg. ciprofloxacin, levofloxacin) due to the risk of disabling, long-lasting and potentially irreversible side effects (including tendon damage, QT prolongation, neuropathies and neuro psychiatric disorder). Use of fluoroquinolones in older patients, those with renal impairment, solid organ transplantation or on systemic corticosteroids increases the risk of tendon damage.

Moderate to Severe Community Acquired and all Hospital-Acquired Infection (Empiric therapy)

Piperacillin/Tazobactam 4.5g TDS/QDS IV  (QDS dosing indication: severe infection, neutropenic sepsis or Pseudomonas aeruginosa infection)

+ Gentamicin/Amikacin once daily IV (Please see Gentamicin / Amikacin dosing schedule).

.

Use Amikacin instead of gentamicin if history of infection or colonisation with gentamicin resistant Gram negative bacteria, severe illness or septic shock.

+ Vancomycin in severe infection, septic shock, or history infection/colonisation with MRSA (Please see Vancomycin dosing schedule).

Penicillin allergy

NOT IgE-mediated/anaphylaxis/severe reaction:

Ceftriaxone 2g once daily IV + Metronidazole 500mg TDS IV + Gentamicin/ Amikacin once daily IV (Please see Gentamicin / Amikacin dosing schedule).

Use Amikacin instead of gentamicin if history of infection or colonisation with gentamicin resistant Gram negative bacteria, severe illness or septic shock.

+ Vancomycin in severe infection, septic shock, or history infection/colonisation with MRSA (Please see Vancomycin dosing schedule).

IgE-mediated/anaphylaxis/severe reaction:

Ciprofloxacin* 400mg BD IV + Metronidazole 500mg TDS IV + Gentamicin/ Amikacin once daily IV (Please see Gentamicin / Amikacin dosing schedule).

Use Amikacin instead of gentamicin if history of infection or colonisation with gentamicin resistant Gram negative bacteria, severe illness or septic shock.

+ Vancomycin in severe infection, septic shock, or history infection/colonisation with MRSA. (Please see Vancomycin dosing schedule).

• Review need for Gentamicin/Amikacin daily. The use of aminoglycosides in combination with other agents (e.g. co-amoxiclav) is rarely required for longer than 3 days. Discuss with microbiology if required.

* Please read the HPRA Drug Safety Alert issued in 2018 and the HPRA Drug Safety Newsletter issued in 2023 highlighting restrictions on use of fluoroquinolones (e.g. ciprofloxacin, levofloxacin) due to the risk of disabling, long-lasting and potentially irreversible side effects (including tendon damage, QT prolongation, neuropathies and neuro psychiatric disorder). Use of fluoroquinolones in older patients, those with renal impairment, solid organ transplantation or on systemic corticosteroids increases the risk of tendon damage.

Antifungal cover

Indications: Upper GI perforation or multiple or recurrent bowel perforations, surgically treated pancreatitis, heavy colonization with Candida spp., and/or yeast identified on Gram stain of samples from infected peritoneal fluid or tissue. Empiric antifungal therapy should be considered for patients with clinical evidence of intra-abdominal infection and significant risk factors for candidiasis, including recent abdominal surgery, anastomotic leaks, or necrotizing pancreatitis.

Fluconazole 400mg once daily IV (loading dose 800mg in severe infection, reduce dose if CrCl <10ml/min) if patient stable, no recent fluconazole use and not colonised with resistant Candida sp.

OR

Anidulafungin 200mg loading dose followed by 100mg once daily IV maintenance dose, if sepsis, critical illness, recent fluconazole use or colonisation/infection with candida species other than C. albicans.

De-escalation to fluconazole IV/PO can be considered where C. albicans has been isolated and clinical condition has stabilised.

Comments

• Duration: If adequate source control, treatment course of 4-7 days is usually sufficient.
• Most clinical treatment failures are due to failure to achieve such source control.
• Consider need for radiological investigations for further assessment if appropriate.
• Aim to rationalise empirical therapy above to pathogen-directed therapy the basis of culture results with a switch to oral agents when suitable.

References

1. Guidelines for the selection of anti-infective agents for complicated intra-abdominal infections. Clin Infect Dis 2010; 501:133-164.
2. The Surgical Infection Society Revised Guidelines on the management of intra-abdominal infections. Surgical Infections 2017.
3. Clinical Practice Guideline for the Management of Candidiasis: 2016 Update by the IDSA

General points

The use of antimicrobials to prevent infection in patients with acute pancreatitis, regardless of disease severity or type (interstitial or necrotizing), is generally not recommended.

Antimicrobials are indicated in patients suspected of developing infected necrosis. This occurs in about 30% of patients with pancreatic necrosis, typically 7-10 days after initial presentation. See Hospital-Acquired Intra-Abdominal Infections guideline for treatment options.

References

1. The Surgical Infection Society Revised Guidelines on the management of intra-abdominal infections. Surgical Infections 2017.
2. NICE Guidelines Pancreatitis (NG104) 2018.
3. American Gastroenterological Association Institute Guideline on Initial Management of Acute Pancreatitis. Gastroenterology 2018;154:1096-1101

General points

• Send blood cultures and ascitic fluid for WCC and culture.
• Inoculating ascitic fluid into blood culture bottles may increase pathogen yield from culture.
• Review previous microbiology test results for history of MDROs – contact microbiology if required.
• Gastroenterology consult advised.

Antibiotics

Prophylaxis of SBP in acute variceal haemorrhage and cirrhosis: Ceftriaxone 1g once daily IV x 7/7

Treatment of SBP: Ceftriaxone 2g once daily IV x 5/7 ( 5 days generally sufficient )

IgE-mediated/anaphylaxis/severe penicillin allergy: * Ciprofloxacin 500mg BD PO or 400mg BD IV (excellent oral bioavailability). Not suitable if patient is already on quinolone prophylaxis - discuss with microbiology.

* Please read the HPRA Drug Safety Alert issued in 2018 and the HPRA Drug Safety Newsletter issued in 2023 highlighting restrictions on use of fluoroquinolones (eg. ciprofloxacin, levofloxacin) due to the risk of disabling, long-lasting and potentially irreversible side effects (including tendon damage, QT prolongation, neuropathies and neuro psychiatric disorder). Use of fluoroquinolones in older patients, those with renal impairment, solid organ transplantation or on systemic corticosteroids increases the risk of tendon damage.

References

Diagnosis, Evaluation, and Management of Ascites, Spontaneous Bacterial Peritonitis and Hepatorenal Syndrome: 2021 Practice Guidance by the American Association for the Study of Liver Diseases.