Initial Workup for Cirrhosis with Ascites
A diagnostic paracentesis should be performed in all patients with new onset grade 2 or 3 ascites, in all patients hospitalized for worsening ascites, and in all patients with any complication of cirrhosis including fever, abdominal pain, gastrointestinal bleeding, hepatic encephalopathy, hypotension, or renal insufficiency. 1
Diagnostic Evaluation
History and Physical Examination
- Assess for risk factors for cirrhosis (alcohol use, viral hepatitis, metabolic syndrome)
- Evaluate for signs of decompensation (jaundice, encephalopathy)
- Perform abdominal examination for shifting dullness and fluid wave tests
- Note that approximately 1,500 mL of fluid must be present before flank dullness is detected 1
- Grade ascites severity:
- Grade 1: Only detected by imaging
- Grade 2: Moderate abdominal distension
- Grade 3: Marked abdominal distension (tense ascites) 1
Laboratory Testing
Blood Tests:
- Complete blood count
- Liver function tests
- Renal function (BUN, creatinine)
- Serum electrolytes
- Coagulation profile (PT/INR)
- Serum albumin (for SAAG calculation) 1
Abdominal Paracentesis (essential component):
Ascitic fluid analysis should include:
- Cell count with differential (neutrophil count)
- Total protein and albumin (calculate SAAG)
- Bacterial culture (bedside inoculation into blood culture bottles)
- Cytology if malignancy is suspected 1
SAAG calculation: Serum albumin minus ascitic fluid albumin
- SAAG ≥1.1 g/dL indicates portal hypertension (97% accuracy) 1
- SAAG <1.1 g/dL suggests other causes of ascites
Additional tests when clinically indicated:
- Ascitic amylase (if pancreatic disease suspected)
- Tuberculosis testing (PCR, culture) if TB peritonitis suspected
- Triglycerides (if chylous ascites suspected) 1
Imaging
- Abdominal ultrasound: Evaluate liver morphology, spleen size, portal vein patency, and confirm presence of ascites 1
- Additional imaging (CT or MRI) may be needed based on clinical suspicion of other pathologies
Interpretation of Results
Diagnostic Criteria for SBP
- Ascitic fluid neutrophil count >250 cells/mm³ indicates spontaneous bacterial peritonitis 1
- Ascitic fluid total protein <1.5 g/dL indicates increased risk for SBP 1
Differential Diagnosis
- Cirrhosis (accounts for 75-85% of ascites cases)
- Malignancy (peritoneal carcinomatosis)
- Heart failure
- Tuberculosis
- Pancreatic disease
- Nephrotic syndrome 1
Management Considerations
All patients with cirrhotic ascites should be considered for liver transplantation evaluation, as the development of ascites indicates poor prognosis (one-year mortality ~40%, two-year mortality ~50%) 1, 2
Initial treatment approach based on ascites grade:
- Grade 1: Sodium restriction alone (80-120 mmol/day)
- Grade 2: Sodium restriction + diuretics (spironolactone + furosemide)
- Grade 3: Large volume paracentesis + sodium restriction + diuretics 2
Diuretic therapy typically starts with spironolactone 100 mg/day, increasing to 400 mg/day if needed 1
Furosemide can be added if spironolactone alone is insufficient, starting at lower doses and titrating up to 160 mg/day with careful monitoring 1, 3
Pitfalls to Avoid
- Do not delay paracentesis due to coagulopathy concerns - paracentesis is safe even with abnormal coagulation profiles 1
- Do not start diuretics before performing diagnostic paracentesis in new-onset ascites 1
- Avoid NSAIDs, ACE inhibitors, and ARBs as they can worsen ascites 2
- Monitor for diuretic complications, especially in patients with cirrhosis and hepatic dysfunction 4, 3
- Be vigilant for hyponatremia during diuretic therapy, which requires specific management based on severity 1
By following this systematic approach to the workup of cirrhotic ascites, clinicians can establish the diagnosis, identify complications like SBP early, and initiate appropriate management to improve outcomes and quality of life.