How to evaluate and treat gross ascites?

Evaluation and Treatment of Gross Ascites

For gross (grade 3) ascites, perform immediate large-volume paracentesis (LVP) removing all accessible fluid, followed by albumin infusion at 8 g per liter removed if >5 liters, then initiate sodium restriction (2 g/day) and combination diuretic therapy with spironolactone 100 mg plus furosemide 40 mg daily. 1, 2

Initial Diagnostic Evaluation

All patients with gross ascites require diagnostic paracentesis before initiating treatment, even without signs of infection. 1, 2

Essential Paracentesis Technique and Testing

• Perform paracentesis 15 cm lateral to the umbilicus in the lower quadrants, avoiding the epigastric vessels 1
• Do not withhold paracentesis for coagulopathy or thrombocytopenia—serious complications occur in <1/1000 procedures 1, 2
• Inoculate at least 10 mL of ascitic fluid into aerobic and anaerobic blood culture bottles at bedside before any antibiotics 1
• Send fluid for: neutrophil count (to exclude spontaneous bacterial peritonitis), total protein, albumin, and simultaneous serum albumin 1, 2

Critical Diagnostic Calculations

• Calculate serum-ascites albumin gradient (SAAG) by subtracting ascitic fluid albumin from serum albumin 1, 2
• SAAG ≥1.1 g/dL indicates portal hypertension with 97% accuracy and confirms cirrhotic ascites 2
• Neutrophil count >250 cells/mm³ diagnoses spontaneous bacterial peritonitis requiring immediate antibiotics 1, 2

Additional Workup

• Obtain abdominal ultrasound to assess liver morphology, splenomegaly, portal vein patency, and exclude masses 1, 2
• Check liver function tests (AST, ALT, bilirubin, alkaline phosphatase), renal function (creatinine, BUN), prothrombin time/INR, and complete blood count 1, 2
• Measure serum and urine electrolytes including spot urine sodium and potassium 1

Immediate Therapeutic Management

Large-Volume Paracentesis

For gross ascites, therapeutic paracentesis is the first-line treatment—remove all accessible fluid in a single session. 1, 3

• Administer albumin at 8 g per liter of ascites removed when removing >5 liters to prevent post-paracentesis circulatory dysfunction 1, 4
• LVP provides immediate symptomatic relief and is safer than prolonged diuretic escalation 3, 5
• Complications are rare; do not delay for mild coagulopathy 1, 2

Sodium Restriction

• Restrict dietary sodium to 2 g/day (90 mmol/day) starting immediately 1, 4, 3
• Provide formal dietician consultation to maximize adherence while preventing malnutrition 1
• Educate patients to avoid adding salt to meals and limit preprepared foods 1
• Fluid restriction is NOT indicated unless serum sodium <125 mmol/L 1, 4

Diuretic Therapy

Initial Regimen for Gross Ascites

Start combination therapy with spironolactone 100 mg daily plus furosemide 40 mg daily, as patients with long-standing gross ascites respond better to combined treatment than monotherapy. 1, 6, 3

• Spironolactone acts as an aldosterone antagonist at the distal tubule, retaining potassium while excreting sodium 6
• Furosemide acts at the loop of Henle and prevents hyperkalemia from spironolactone 7
• Never use furosemide as monotherapy—it is less effective than spironolactone in portal hypertension 4

Dose Titration

• Increase spironolactone stepwise up to 400 mg/day, waiting at least 72 hours between increases due to long half-life (16.5 hours for active metabolites) 1, 6
• Increase furosemide up to 160 mg/day as needed 1, 8
• Maintain spironolactone:furosemide ratio of 100:40 during titration 1, 3
• Target weight loss of 0.5 kg/day without peripheral edema, or up to 1 kg/day with edema 1

Monitoring Diuretic Response

• Check spot urine sodium/potassium ratio: if >1, patient should be losing weight; if not, suspect dietary noncompliance 1
• If spot urine Na/K ratio ≤1, insufficient natriuresis exists—increase diuretics 1
• 24-hour urine sodium <80 mmol/day indicates inadequate diuretic dosing 1

Critical Monitoring and Safety

Laboratory Surveillance

• Monitor serum potassium within 1 week of initiation or dose changes, then regularly 6
• Check serum creatinine, electrolytes, and renal function frequently during diuresis 1, 7
• If creatinine rises significantly or exceeds 150 μmol/L, stop diuretics immediately 4

Electrolyte Complications

• Hyperkalemia risk increases with spironolactone, especially with ACE inhibitors, ARBs, NSAIDs, or renal impairment 6
• For serum sodium <120 mmol/L, stop diuretics and consider volume expansion with albumin 4
• Monitor for hyponatremia, hypomagnesemia, hypocalcemia, and metabolic alkalosis 6

Hepatic Complications

In cirrhotic patients, diuretic therapy must be initiated in the hospital with strict observation, as sudden fluid shifts can precipitate hepatic encephalopathy or coma. 7

• Excessive diuresis causes symptomatic dehydration, hypotension, and acute kidney injury 6
• If increasing azotemia and oliguria occur, discontinue diuretics immediately 7
• Supplemental potassium and aldosterone antagonists help prevent hypokalemia and metabolic alkalosis 7

Refractory Ascites Management

Ascites is refractory when it cannot be mobilized or recurs early despite sodium restriction and maximum diuretics (spironolactone 400 mg/day plus furosemide 160 mg/day). 1, 8

• Treat with serial large-volume paracentesis plus albumin 8, 5
• Consider transjugular intrahepatic portosystemic shunt (TIPS) for eligible patients 3, 8, 5
• Refer all patients with ascites for liver transplantation evaluation, as ascites development reduces 5-year survival from 80% to 30% 2, 3

Key Pitfalls to Avoid

• Never assume alcoholic patients have alcoholic liver disease—always investigate other causes 1
• Do not restrict fluids unless hyponatremia is present 1, 4
• Avoid NSAIDs, which reduce diuretic efficacy and worsen renal function 6
• Do not give fresh frozen plasma before paracentesis—it is not supported by evidence 1
• Spironolactone causes dose-dependent gynecomastia in ~9% of males, usually reversible 6
• Monitor for lithium toxicity if coadministered, as spironolactone reduces lithium clearance 6