Liver Abscess

Liver Abscess: Intro & Types - Abscess Alert!

Localized collection of pus within the liver parenchyma.

• Types:
  • Pyogenic Liver Abscess (PLA):
    • Most common type globally.
    • Bacterial origin (e.g., E. coli, Klebsiella, Streptococcus).
    • Polymicrobial common.
  • Amoebic Liver Abscess (ALA):
    • Caused by Entamoeba histolytica.
    • Common in developing countries.
    • Typically solitary; "Anchovy sauce" pus.

⭐ Amoebic liver abscess is most commonly found in the posterior-superior aspect of the right lobe of the liver.

Liver Abscess: Etiopathogenesis - Bug Invasion Routes

• Causative Organisms:
  • Pyogenic: E. coli (MC), Klebsiella, Strep., Staph., Anaerobes.
  • Amoebic: Entamoeba histolytica.
• Invasion Routes:
  • Biliary tree (MC pyogenic): Ascending cholangitis.
  • Portal vein: Pylephlebitis (e.g., gut sepsis).
  • Hepatic artery: Hematogenous spread.
  • Direct extension: Contiguous infection.
  • Penetrating trauma.

⭐ The most common route of infection for pyogenic liver abscess is via the biliary tree (ascending cholangitis); E. coli is the most common causative organism.

Liver Abscess: Clinical Features - Fever & Pain Saga

• Symptoms:
  • Fever: Most common (>90%), often high, intermittent, with chills/rigors.
  • Pain: RUQ, dull ache, pleuritic possible; may radiate to R shoulder.
  • Malaise, anorexia, weight loss.
  • Nausea, vomiting.
  • Jaundice (infrequent, ~10-20%).
• Signs:
  • Hepatomegaly: Tender.
  • RUQ tenderness: Often marked.
  • Intercostal tenderness.

⭐ Fever is the most common symptom of liver abscess, often accompanied by right upper quadrant pain and tenderness.

Liver Abscess: Diagnostic Workup - Spotting the Pus

• Lab Tests:
  • CBC: ↑WBC (Leukocytosis)
  • LFTs: ↑ALP, ↑Bilirubin
  • Inflammatory: ↑ESR, ↑CRP
  • Blood Cultures (pyogenic)
  • Amoebic Serology: IHA/ELISA (E. histolytica, >90% sensitive)
• Imaging:
  • USG: Initial choice; hypoechoic.
  • CT: More sensitive (small/multiple abscesses, complications); rim enhancement.
  • CXR: ↑Rt hemidiaphragm.
• Aspiration (USG/CT-guided):
  • Pus: Microscopy, culture (aerobic/anaerobic), amoebic tests.
  • 📌 "Anchovy sauce" pus (amoebic).

⭐ Ultrasound is the initial imaging modality of choice for suspected liver abscess, with CT scan being more sensitive for smaller abscesses and complications.

Liver Abscess: Management - Drain & Conquer

• Approach: Prompt antibiotics & drainage when indicated.

• Medical Therapy:

  • Pyogenic: IV broad-spectrum antibiotics (e.g., 3rd gen Cephalosporin + Metronidazole).
  • Amoebic: Metronidazole (or Tinidazole), followed by luminal amoebicide (e.g., Diloxanide).

• Percutaneous Drainage (PNA/PCD):

  • Indications: Size >5 cm, no response to antibiotics (48-72h), high rupture risk.

• Surgical Drainage: Reserved for failed percutaneous attempts, multiloculated/thick pus, or rupture with peritonitis.

⭐ 'Anchovy sauce' or 'chocolate-colored' pus on aspiration is characteristic of amoebic liver abscess.

Liver Abscess: Complications - Trouble Aftermath

• Rupture: Most common serious complication.
  • Pleural (empyema), pericardial (tamponade), peritoneal (peritonitis).
• Sepsis, septic shock.
• Subphrenic abscess.
• Thrombosis: Portal vein, hepatic veins (Budd-Chiari syndrome).
• Bronchohepatic fistula.
• Secondary infection.

⭐ Rupture into adjacent structures (pleura, pericardium, peritoneum) is the most serious complication of liver abscess.

High‑Yield Points - ⚡ Biggest Takeaways

• Amoebic Liver Abscess (ALA), caused by E. histolytica, is more common in India than Pyogenic (PLA).
• PLA is often polymicrobial (E. coli, Klebsiella).
• Key symptoms: Fever, RUQ pain, and tender hepatomegaly.
• "Anchovy sauce" pus (sterile on bacterial culture) is classic for ALA.
• Ultrasound (USG) is the initial investigation of choice.
• Treatment: Metronidazole for ALA; antibiotics plus drainage for PLA.
• Most dreaded complication: Rupture (pleural, pericardial, peritoneal).