What does blood in ascites fluid indicate and what are the causes?

Blood in Ascites: Diagnostic Significance and Causes

Blood in ascitic fluid indicates a potentially serious condition that requires prompt evaluation and management, with the most common causes being traumatic paracentesis, hepatocellular carcinoma, or spontaneous intraperitoneal hemorrhage from ruptured intra-abdominal blood vessels. 1

Diagnostic Significance of Bloody Ascites

Bloody ascites can be categorized into two main presentations:

1. Grossly bloody ascites:

   • Occurs in approximately 5% of cirrhotic patients with ascites 2
   • Associated with poorer prognosis compared to clear ascites in patients with similar liver function 2

2. Microscopically bloody ascites:

   • Detected through elevated RBC count in ascitic fluid
   • May indicate underlying pathology even when not visible to the naked eye

Major Causes of Bloody Ascites

1. Traumatic Paracentesis

• Most common immediate cause of blood in ascitic fluid
• Results from puncture of:
  • Superficial abdominal wall veins (superficial epigastric vein)
  • Mesenteric varices
  • Intraperitoneal collateral vessels (paraumbilical vein)
  • Inferior epigastric artery or deep circumflex iliac artery 1

2. Malignancy

• Hepatocellular carcinoma (most common malignant cause)
• Peritoneal carcinomatosis
• Massive liver metastases 1, 2

3. Spontaneous Intraperitoneal Hemorrhage

• From ruptured varices or other collateral vessels
• Spontaneous splenic rupture
• Retroperitoneal vein bleeding 2

4. Other Causes

• Tuberculous peritonitis
• Recent abdominal trauma
• Pancreatitis with hemorrhagic complications
• Budd-Chiari syndrome (hepatic vein thrombosis)
• Sinusoidal obstruction syndrome 1

Evaluation of Bloody Ascites

Initial Assessment

1. Determine if iatrogenic or spontaneous:

   • Timing relative to paracentesis (immediate vs. delayed)
   • Symptoms may appear 6-24 hours after paracentesis, but can be delayed up to a week 1

2. Ascitic fluid analysis:

   • Cell count and differential
   • Total protein and albumin (for SAAG calculation)
   • RBC count (>24,000/mcL suggests significant hemorrhage) 3
   • Culture if infection suspected 1

3. SAAG calculation:

   • ≥1.1 g/dL indicates portal hypertension (97% accuracy) 1, 4
   • <1.1 g/dL suggests non-portal hypertensive causes 1

Additional Testing Based on Clinical Suspicion

• Cytology for suspected malignancy (sensitivity 96.7% with three samples) 1
• Imaging (ultrasound with Doppler) to evaluate:
  • Liver morphology
  • Portal and hepatic vein patency
  • Presence of hepatocellular carcinoma 4

Management Considerations

For Iatrogenic Bleeding

• Most cases can be managed with:
  • Fluid resuscitation
  • Blood transfusion if needed
  • Correction of coagulation disorders 1

For Severe or Persistent Bleeding

• Consider more aggressive interventions:
  • Transcatheter coil embolization
  • Laparoscopy with vessel ligation
  • Transjugular intrahepatic portal-systemic shunt (TIPS) in severe cases 1

Special Considerations

• Contraindications to paracentesis to prevent bloody ascites:

  • Clinically evident hyperfibrinolysis
  • Disseminated intravascular coagulation
  • Severe liver or renal dysfunction increases risk 1

• Relative contraindications:

  • Pregnancy
  • Severe intestinal distension
  • History of extensive abdominal surgery 1

Prognostic Implications

Patients with spontaneous bloody ascites have a significantly poorer prognosis than those with similar liver tests and clear ascites, suggesting it may be a marker of more advanced disease 2.

Clinical Pearls

• Bloody ascites warrants thorough investigation even when it appears to be from traumatic paracentesis
• The presence of blood in ascites fluid should never be dismissed as insignificant
• In cirrhotic patients with bloody ascites, always consider hepatocellular carcinoma as a potential cause