What is the appropriate evaluation and management of ascites?

Evaluation and Management of Ascites

All patients with new-onset grade 2 or 3 ascites require immediate diagnostic paracentesis before initiating any treatment, and therapeutic large-volume paracentesis is the first-line intervention for symptomatic ascites, followed by sodium restriction and combination diuretic therapy. 1, 2

Initial Diagnostic Evaluation

Mandatory Paracentesis Indications

• Perform diagnostic paracentesis in all patients with:
  • New-onset grade 2 (moderate) or grade 3 (large/tense) ascites 1
  • Any hospitalization for worsening ascites or complications of cirrhosis 1
  • Fever, abdominal pain, encephalopathy, gastrointestinal bleeding, hypotension, or renal insufficiency 1, 2
  • Each hour of delay increases in-hospital mortality by 3.3% when spontaneous bacterial peritonitis (SBP) is present 3

Paracentesis Technique

• Perform paracentesis 15 cm lateral to the umbilicus in the lower quadrants to avoid epigastric vessels 2
• Do not withhold paracentesis for coagulopathy or thrombocytopenia—serious bleeding complications occur in <1 in 1000 procedures 2
• Inoculate ≥10 mL of ascitic fluid into both aerobic and anaerobic blood culture bottles at bedside before any antibiotics are given 1, 2

Essential Ascitic Fluid Tests

For first episode of ascites (inpatients and outpatients): 1

• Neutrophil (PMN) count—>250 cells/mm³ diagnoses SBP and requires immediate empiric antibiotics 1, 2
• Serum-ascites albumin gradient (SAAG)—subtract ascitic fluid albumin from simultaneously obtained serum albumin 1
• Total protein concentration 1
• Culture (bedside inoculation into blood culture bottles) 1

For recurrent ascites (inpatients only): 1

• PMN count and culture 1
• Protein concentration only when primary SBP prophylaxis is being considered 1
• SAAG is not needed for recurrent ascites 1

Interpreting SAAG

• SAAG ≥1.1 g/dL indicates portal hypertension with 97% accuracy (cirrhosis, cardiac failure, massive liver metastases) 1, 4
• SAAG <1.1 g/dL excludes portal hypertension (peritoneal carcinomatosis, tuberculosis, pancreatic disease) 1, 4

Additional Baseline Evaluation

• History focusing on risk factors for chronic liver disease (alcohol, viral hepatitis, metabolic disease, family history) 1
• Abdominal Doppler ultrasound to confirm ascites and identify portal vein thrombosis or other abnormalities 1
• Laboratory assessment: liver function tests, renal function, serum and urine electrolytes 1

Management of Ascites

Grading System

• Grade 1 (mild): Detectable only by ultrasound—no treatment required 1, 3
• Grade 2 (moderate): Moderate symmetrical distension with positive shifting dullness 1, 3
• Grade 3 (large/tense): Marked abdominal distension 1, 3

First-Line Treatment for Grade 2-3 Ascites

Therapeutic Paracentesis:

• Remove all accessible ascitic fluid in a single session for symptomatic relief 2
• Administer albumin at 8 g per liter of ascites removed when draining >5 liters to prevent post-paracentesis circulatory dysfunction 2, 3
• The peritoneal membrane can only reabsorb approximately 500 mL per day, making large-volume paracentesis more effective than diuretics alone for massive ascites 1, 3

Dietary Sodium Restriction:

• Restrict sodium intake to <2 g/day (88 mmol/day) immediately 1, 2
• Provide formal dietician consultation to maximize adherence while preventing malnutrition 2
• Fluid restriction is NOT indicated unless serum sodium <125 mEq/L 1, 2

Diuretic Therapy

Initial Regimen:

• Start combination therapy with spironolactone 100 mg daily PLUS furosemide 40 mg daily 2
• Patients with long-standing ascites respond better to combination therapy than monotherapy 2
• Never use furosemide as monotherapy—it is less effective than spironolactone in portal hypertension 2

Dose Escalation:

• Increase spironolactone stepwise up to maximum 400 mg/day, waiting at least 72 hours (3-5 days) between increases due to long half-life 1, 2
• Increase furosemide up to maximum 160 mg/day as needed 1
• Maintain the 100:40 mg ratio of spironolactone to furosemide during dose escalation 1

Monitoring Weight Loss:

• Target weight loss of 0.5 kg/day in patients without peripheral edema 1
• Target weight loss up to 1 kg/day in patients with peripheral edema 1
• Exceeding these rates risks plasma volume contraction, renal failure, and hyponatremia 1

Critical Monitoring Parameters

Laboratory Monitoring:

• Check serum potassium within 1 week of diuretic initiation or dose changes, then regularly 2
• Monitor serum creatinine, electrolytes, and renal function frequently during diuresis 2
• Assess 24-hour urinary sodium excretion or spot urine Na/K ratio to guide therapy 1
• When spot urine Na/K ratio >1, the patient is excreting more sodium than potassium, indicating adequate diuretic effect 1

Stopping Diuretics:

• If creatinine rises significantly or exceeds 150 μmol/L (1.7 mg/dL), stop diuretics immediately 2
• For serum sodium <120 mEq/L, stop diuretics and consider volume expansion with albumin 2
• Discontinue diuretics for severe hyperkalemia or symptomatic hyponatremia 1

Management of Refractory Ascites

Definition:

• Ascites that cannot be mobilized or recurs early despite sodium restriction and maximum diuretic doses (spironolactone 400 mg/day plus furosemide 160 mg/day) 2, 5

Treatment Options:

• Serial large-volume paracentesis with albumin replacement 1, 5
• Transjugular intrahepatic portosystemic shunt (TIPS) in selected patients 5
• Liver transplantation is the only definitive treatment that improves survival 5

Spontaneous Bacterial Peritonitis Management

Diagnosis and Treatment:

• PMN count >250 cells/mm³ requires immediate empiric IV antibiotics without waiting for culture results 1, 2
• First-line: IV cefotaxime 2 g every 12 hours when multidrug-resistant organisms are uncommon 2
• For nosocomial infections, recent hospitalizations, or ICU patients: start carbapenem therapy—inappropriate initial therapy in septic shock increases mortality tenfold 2
• Narrow or de-escalate antibiotics once culture and susceptibility results are available 2
• SBP occurs in 10% of hospitalized cirrhotic patients with 20% in-hospital mortality despite treatment 3

Prognosis and Liver Transplantation

Survival Data:

• Development of ascites reduces five-year survival from ~80% in compensated cirrhosis to ~30% in decompensated cirrhosis 1
• One and two-year mortality after ascites development is approximately 40% and 50%, respectively 1
• One-year survival after SBP is only 34% 3

Transplant Referral:

• All patients with ascites should be considered for liver transplantation evaluation 1, 2
• Patients with refractory ascites, SBP, or hepatorenal syndrome are priority candidates 3

Critical Pitfalls to Avoid

• Do not assume cirrhosis is the cause—while 75-85% of ascites is cirrhotic, always calculate SAAG to exclude malignancy, tuberculosis, and cardiac failure 1, 3
• Do not restrict fluids unless serum sodium <125 mEq/L—unnecessary fluid restriction worsens quality of life without benefit 1, 2
• Avoid NSAIDs—they reduce diuretic efficacy and worsen renal function 2
• Do not give fresh frozen plasma before paracentesis—it is not supported by evidence and bleeding complications are rare 2
• Do not rely solely on physical examination in obese patients—proceed directly to ultrasound 3
• Do not delay paracentesis in hospitalized patients—each hour of delay increases mortality by 3.3% when SBP is present 3