How is ascites diagnosed and managed?

Diagnosis and Management of Ascites

Abdominal paracentesis with appropriate ascitic fluid analysis is the most rapid and cost-effective method for diagnosing the cause of ascites and should be performed in all cirrhotic patients with ascites on hospital admission. 1

Diagnostic Approach

Physical Examination

• Look for a full, bulging abdomen with flank dullness
• Test for "shifting dullness" (83% sensitivity, 56% specificity)
• Approximately 1500 mL of fluid must be present before flank dullness is detected 1
• If no flank dullness is present, the patient has <10% chance of having ascites
• In obese patients, abdominal ultrasound may be required to confirm presence of fluid 1

Initial Evaluation

1. History: Risk factors for liver disease, heart disease, malignancy, tuberculosis, pancreatitis
2. Physical examination: Shifting dullness, bulging flanks, fluid wave
3. Abdominal ultrasound: Confirms presence of ascites, evaluates liver for cirrhosis, HCC, portal vein thrombosis
4. Laboratory assessment: Liver and renal function, serum and urine electrolytes
5. Diagnostic paracentesis: Essential for determining etiology 1

Paracentesis Analysis

For first episode of ascites, test the following:

• SAAG (serum-ascites albumin gradient): Calculated by subtracting ascitic fluid albumin from serum albumin
• PMN count: To detect spontaneous bacterial peritonitis
• Culture: For bacterial infection
• Protein concentration: For risk assessment of SBP
• Cytology: When causes other than cirrhosis are suspected 1

Management Algorithm

Grade 1 (Mild) Ascites

• Only detected by ultrasound
• Treatment: Sodium restriction alone (80-120 mmol/day, equivalent to 4.6-6.9 g of salt) 2

Grade 2 (Moderate) Ascites

• Moderate abdominal distension
• Treatment:
  1. Sodium restriction (90 mmol salt/day or 5.2 g salt/day) 1
  2. Diuretic therapy:
     • Start with spironolactone alone (100 mg/day), increasing to 400 mg/day if needed 1
     • If inadequate response, add furosemide up to 160 mg/day 1

Grade 3 (Large/Tense) Ascites

• Marked abdominal distension
• Treatment:
  1. Initial large volume paracentesis (LVP)
  2. Volume expansion:
     • For <5 liters: Synthetic plasma expander (150-200 ml of gelofusine)
     • For >5 liters: Albumin (8g albumin/L of ascites removed) 1
  3. Follow with sodium restriction and diuretic therapy as above

Refractory Ascites

• Defined as inability to resolve ascites with sodium restriction and maximum diuretic doses (400 mg/day spironolactone and 160 mg/day furosemide) 3
• Treatment options:
  1. Periodic large volume paracentesis with albumin replacement
  2. Transjugular intrahepatic portosystemic shunt (TIPS) for suitable candidates 1
  3. Consider liver transplantation evaluation 1

Management of Complications

Hyponatremia

• Serum sodium 126-135 mmol/L with normal creatinine: Continue diuretics, monitor electrolytes
• Serum sodium 121-125 mmol/L with normal creatinine: Consider stopping diuretics
• Serum sodium 121-125 mmol/L with elevated creatinine: Stop diuretics and give volume expansion
• Serum sodium <120 mmol/L: Stop diuretics, consider volume expansion with colloid or saline 1
• Fluid restriction is only necessary with severe hyponatremia (<120-125 mmol/L) 2

Spontaneous Bacterial Peritonitis (SBP)

• Diagnosed when ascitic fluid neutrophil count >250 cells/mm³
• Start empiric antibiotic therapy immediately
• Third-generation cephalosporins are most effective 1
• Consider albumin administration (1.5 g/kg) in patients with renal impairment

Important Considerations

• Coagulopathy is not a contraindication to paracentesis in cirrhotic patients 1
• Complications from paracentesis are rare (approximately 1% risk of abdominal wall hematomas) 1
• Patients with ascites should be considered for liver transplantation evaluation 1
• Avoid medications that may worsen ascites: NSAIDs, ACE inhibitors, angiotensin receptor blockers 2
• Ensure adequate nutrition (35-40 kcal/kg/day and 1.2-1.5 g protein/kg/day) 2

Monitoring

• Regular weight measurements
• Periodic ultrasound examinations
• Monitor electrolytes, renal function
• Screen for hepatocellular carcinoma at diagnosis and every 6 months thereafter 2

The development of ascites marks a significant decline in prognosis, with 5-year survival dropping from 80% to 30% without liver transplantation 1. Therefore, early diagnosis, proper management, and timely referral for transplantation evaluation are critical for improving outcomes.