What is the initial management for a patient presenting with ascitic fluid?

Initial Management of Ascites

The initial management for a patient presenting with ascites should include a diagnostic paracentesis with ascitic fluid analysis to determine the cause and rule out spontaneous bacterial peritonitis (SBP). 1, 2

Diagnostic Approach

• A diagnostic paracentesis is mandatory for all patients with new-onset ascites or clinically apparent ascites to establish the diagnosis and exclude complications 2, 1
• Paracentesis should not be delayed even in patients with coagulopathy, as bleeding complications are rare (occurring in less than 1 per 1,000 procedures) 2
• No prophylactic use of fresh frozen plasma or platelets before paracentesis is recommended 2

Essential Ascitic Fluid Analysis:

• Serum-ascites albumin gradient (SAAG): Calculate by subtracting ascitic fluid albumin from serum albumin (collected on the same day)
  • SAAG ≥1.1 g/dL indicates portal hypertension with 97% accuracy 2, 1
• Cell count with differential: To rule out SBP (neutrophil count >250 cells/mm³ is diagnostic) 2, 1
• Total protein concentration: Levels <15 g/L indicate increased risk of SBP 2
• Bacterial culture: Inoculate fluid directly into blood culture bottles at bedside when infection is suspected 2, 1

Additional Testing Based on Clinical Suspicion:

• Amylase: When pancreatic disease is suspected 2
• Carcinoembryonic antigen (CEA): Values >5 ng/mL suggest gut perforation 2
• Alkaline phosphatase: Values >240 units/L may indicate gut perforation 2
• Lactate dehydrogenase, glucose: To differentiate spontaneous from secondary bacterial peritonitis 2

Treatment Algorithm

1. Determine Cause of Ascites:

• Cirrhosis accounts for approximately 75% of ascites cases in Western countries 2
• Other causes include malignancy, heart failure, tuberculosis, and pancreatic disease 2, 3

2. For Uncomplicated Cirrhotic Ascites:

• Implement sodium restriction (5-6.5g salt/day) 1
• Start diuretic therapy:
  • Begin with spironolactone 100 mg/day (can increase up to 400 mg/day) 1, 4
  • If inadequate response, add furosemide starting at 40 mg/day (can increase up to 160 mg/day) 1, 4
  • Monitor for complications including hyponatremia, renal impairment, and hepatic encephalopathy 5

3. For Large Volume Ascites:

• Perform therapeutic paracentesis 2
• For paracentesis <5 liters: Follow with synthetic plasma expander (150-200 ml of gelofusine) 2
• For large-volume paracentesis (>5 liters): Administer albumin (8g per liter of ascites removed) to prevent post-paracentesis circulatory dysfunction 2, 6

4. For Suspected or Confirmed SBP:

• Start empiric antibiotic therapy immediately when ascitic fluid neutrophil count exceeds 250 cells/mm³ 2, 1
• Third-generation cephalosporins (e.g., cefotaxime) are most extensively studied and effective 2
• For patients with SBP and signs of renal impairment, administer albumin (1.5 g/kg in first six hours, followed by 1 g/kg on day 3) 2

Special Considerations

• Patients with refractory ascites (approximately 10% of cases) may require:
  • Repeated large-volume paracentesis with albumin 7
  • Transjugular intrahepatic portosystemic shunt (TIPS) for suitable candidates 2, 7
• All patients with ascites due to cirrhosis should be evaluated for liver transplantation, as it offers definitive treatment 2, 1, 7

Common Pitfalls to Avoid

• Delaying diagnostic paracentesis, which increases mortality risk 1
• Failing to screen for SBP in hospitalized cirrhotic patients with ascites 1
• Inadequate sodium restriction, limiting diuretic effectiveness 1
• Sudden alterations of fluid and electrolyte balance in cirrhotic patients, which may precipitate hepatic coma 5