Liver%20abscess Treatment

Principles of Empiric Antibiotic Therapy

• Antibiotics should be started as soon as pyogenic liver abscess is considered
• Antibiotic therapy alone w/o drainage should be considered only in patients w/ small abscesses (<3-5 cm) that are not amenable to drainage & in those in whom drainage will pose an unreasonable risk
• Initial antibiotics should be broad spectrum to cover common causative pathogens of pyogenic liver abscess
• Metronidazole should be part of the initial therapy to provide empiric treatment for both anaerobes & E histolytica
• Antibiotics should be based on local antimicrobial resistance patterns & modified based on culture & sensitivity testing results

Antibiotic Options

• Ampicillin + Aminoglycoside
  
  • Should be part of antibiotic regimen when a biliary source is suspected

• Cephalosporins
  
  • 2nd or 3rd generation cephalosporins are recommended when a colonic source is considered
  • Provide excellent coverage for enteric bacilli
  • Some cephalosporins have coverage against anaerobes

• Metronidazole or Clindamycin
  
  • Should be included in antibiotic regimen to cover for anaerobes if other antibiotics being used do not have anaerobic coverage
  • If amoebiasis is suspected, Metronidazole should be started

• Other antibiotics/antibiotic combinations that may be used for pyogenic liver abscesses include:
  
  • Antipseudomonal penicillins w/ or w/o beta-lactamase inhibitor
  • Carbapenems
    
    • Recommended for patients w/ diabetes mellitus (DM) due to risk of extended-spectrum beta-lactamase (ESBL) infection
  • Fluoroquinolone + Metronidazole +/- aminoglycoside
  • Vancomycin + Metronidazole +/- aminoglycoside

Drugs for Amoebic Liver Abscess

• Chloroquine
  
  • May be used as an adjunct w/ Metronidazole in patients w/ large & multiple abscesses
  • Active against E histolytica trophozoites, achieves high concentrations in hepatic tissue

• Metronidazole
  
  • Highly lethal to E histolytica trophozoites
  • Absorbed quickly through the gut w/ excellent bioavailability

• Secnidazole, Tinidazole
  
  • May be substituted for Metronidazole in uncomplicated cases of invasive amoebiasis

• Luminal amoebicides eg Diloxanide furoate, Etofamide, Iodoquinol, Nitazoxanide & Paromomycin are active against E histolytica cysts & trophozoites in the intestine

Duration of Antibiotic Therapy

Pyogenic Liver Abscess

• Duration of therapy should be based on severity of infection & patient’s response
• Intravenous (IV) antibiotics should be continued for at least 2 weeks; therapy may be continued through the oral route afterwards for up to 6 weeks
• Multiple abscesses may need up to 12 weeks of antibiotic treatment

Amoebic Abscess

• Intravenous (IV) Metronidazole should be given for 5-10 days
• Following a course of Metronidazole, an oral luminal amoebicide should be given for 7 days to eradicate residual amoeba in the intestines

Indications for Drainage

• Most pyogenic abscesses require drainage
  
  • If multiple abscesses are present, only the largest abscess may require aspiration
  • Dispensing w/ a drainage procedure (ie giving antibiotics alone) should be considered only in patients w/ small abscesses not amenable to drainage or in those for whom drainage is too risky
• Patients w/ amoebic abscesses require drainage only for very large lesions & for those in whom rupture is imminent

Percutaneous Needle Aspiration

• Done under computed tomography (CT) scan or ultrasound guidance; often the initial diagnostic procedure performed for a single abscess ≤5 cm
• Requires only local anesthesia & minimal sedation
• Allows sampling of small &/or multiple lesions for culture; may do away w/ the need for catheter placement

Percutaneous Catheter Drainage

• Standard of care for most liver abscesses
• Entails placement of a catheter under ultrasound or computed tomography (CT) scan guidance followed by daily flushing
• Should be the initial intervention for small abscesses <5 cm & for single abscess >5 cm
• May be used for draining multiple abscesses
• Advantages: Does not require general anesthesia, allows gradual drainage, faster recovery rate
• Contraindications: Complicated thick-walled abscess w/ viscous pus, peritonitis, complicated access

Surgical Drainage

• Indications for surgical drainage: Treatment of underlying intra-abdominal disorders including peritonitis, failure of previous percutaneous catheter drainage, multiple & loculated abscesses, ruptured abscess, viscous abscess obstructing the drain, large abscesses >5 cm
• Open drainage may be through the transperitoneal or transpleural approach
• Laparoscopic drainage enables exploration of entire abdomen w/ significantly reduced patient morbidity
• Possible complications of drainage include recurrent pyogenic hepatic abscess, intra-abdominal abscess, kidney or liver failure, surgical wound infection

Endoscopic Retrograde Cholangiopancreatography (ERCP)

• May be used in patients w/ prior biliary procedures & whose infection is connected w/ the biliary tree