What is the initial management of ascites (accumulation of fluid in the peritoneal cavity)?

Initial Management of Ascites

The initial management of ascites requires immediate diagnostic paracentesis in all patients with new-onset grade 2 or 3 ascites to determine etiology and exclude spontaneous bacterial peritonitis, followed by sodium restriction and diuretic therapy with spironolactone as first-line treatment for cirrhotic ascites. 1

Immediate Diagnostic Evaluation

Essential First Step: Diagnostic Paracentesis

• Perform diagnostic paracentesis before initiating any therapy in all patients with new-onset grade 2 or 3 ascites (clinically detectable ascites) 1
• This procedure is mandatory even in outpatients with first episode of ascites to establish diagnosis and exclude complications 1

Required Ascitic Fluid Analysis

The following tests must be obtained on the initial paracentesis specimen 1:

• Neutrophil count (manual or automated): Values >250 cells/µL indicate spontaneous bacterial peritonitis requiring immediate antibiotic therapy 1
• Ascitic fluid albumin and total protein: Calculate serum-ascites albumin gradient (SAAG) and assess SBP risk 1
• Bedside inoculation of blood culture bottles (10 mL each): Increases bacterial culture sensitivity to approximately 80% compared to 50% with traditional methods 1

Calculate SAAG for Etiology

• SAAG ≥1.1 g/dL indicates portal hypertension with 97% accuracy (cirrhosis, heart failure, Budd-Chiari) 1
• SAAG <1.1 g/dL indicates non-portal hypertensive causes (peritoneal carcinomatosis, tuberculosis, pancreatic ascites, nephrotic syndrome) 1
• This gradient determines whether sodium restriction and diuretics will be effective 1

Additional Clinical Assessment

• Complete history focusing on risk factors for chronic liver disease (alcohol, viral hepatitis, metabolic syndrome), heart disease, malignancy, and tuberculosis exposure 1
• Physical examination for stigmata of chronic liver disease, cardiac disease, and abdominal masses 1
• Abdominal Doppler ultrasound to assess liver parenchyma, portal vein patency, and exclude masses 1
• Laboratory assessment: liver function tests, renal function (creatinine), serum and urine electrolytes (particularly sodium) 1

Initial Therapeutic Management for Cirrhotic Ascites

For Patients with SAAG ≥1.1 g/dL (Portal Hypertension)

First-Line Treatment: Sodium Restriction + Spironolactone 2, 3

Dietary Sodium Restriction

• Restrict dietary sodium to 80-100 mmol/day (approximately 2 grams sodium or 5 grams salt per day) 2
• This is effective as monotherapy in only a minority of patients with mild ascites 2

Diuretic Therapy

• Start with spironolactone 100 mg once daily as the aldosterone antagonist addresses the primary pathophysiologic mechanism of sodium retention 4, 2
• Spironolactone should be taken consistently with regard to meals due to food increasing bioavailability by 95% 4
• If inadequate response after 3-5 days, add furosemide 40 mg once daily to the spironolactone 2
• Maintain a 100:40 mg ratio of spironolactone to furosemide when escalating doses in a stepwise fashion (e.g., 200:80 mg, then 300:120 mg, maximum 400:160 mg) 2

Critical Pitfall to Avoid: In patients with hepatic cirrhosis and ascites, diuretic therapy should be initiated in the hospital setting to allow close monitoring for hepatic encephalopathy, electrolyte disturbances, and renal dysfunction 5

Monitoring During Diuretic Therapy

• Monitor serum electrolytes (particularly potassium and sodium), creatinine, and body weight 4, 5
• Avoid potassium supplementation, salt substitutes containing potassium, or drugs that increase potassium (ACE inhibitors, ARBs, NSAIDs) due to severe hyperkalemia risk with spironolactone 4
• Target weight loss should not exceed 0.5 kg/day in patients without peripheral edema or 1 kg/day in those with edema 2
• Discontinue diuretics if increasing azotemia and oliguria occur, as this indicates worsening renal function 5

For Tense Ascites (Grade 3)

• Large-volume paracentesis (LVP) is the treatment of choice for rapid relief of symptoms 2, 6
• Remove as much fluid as needed for symptomatic relief 2
• Administer intravenous albumin (8 g per liter of ascites removed) when removing >5 liters to prevent post-paracentesis circulatory dysfunction 3, 6
• Follow with sodium restriction and diuretics to prevent reaccumulation 2, 6

For Non-Portal Hypertensive Ascites (SAAG <1.1 g/dL)

• Sodium restriction and diuretics are generally not effective except in nephrotic syndrome 1
• Treatment must target the underlying cause (chemotherapy for malignancy, antituberculous therapy for TB peritonitis) 1

Critical Prognostic Consideration

Refer all patients with new-onset ascites for liver transplantation evaluation, as the development of ascites reduces 5-year survival from 80% to approximately 30% and represents hepatic decompensation 1

Special Consideration: Alcohol-Related Cirrhosis

• Alcohol cessation is the single most important intervention in alcohol-related cirrhotic ascites, as abstinence can result in dramatic improvement with 75% 3-year survival in Child-Pugh C patients who stop drinking versus 0% in those who continue 1
• Ascites may resolve or become more responsive to medical therapy with sustained abstinence 1