What is the recommended procedure for an adult patient with ascites, likely due to liver disease, cancer, or other conditions, with potential underlying conditions such as cirrhosis, heart failure, or impaired renal function?

Ascitic Tapping Procedure

Indications for Paracentesis

Perform diagnostic paracentesis on all patients with new-onset ascites and all hospitalized patients with worsening ascites or complications of cirrhosis. 1, 2, 3

• New-onset grade 2 or 3 ascites requires diagnostic tap to determine the serum-ascites albumin gradient (SAAG) and rule out spontaneous bacterial peritonitis 2, 3
• Therapeutic paracentesis is indicated for tense ascites causing abdominal wall distension, difficulty breathing, or eating problems 2
• Admission surveillance taps detect unexpected infection in hospitalized patients 1

Site Selection and Technique

The left lower quadrant is the preferred location for paracentesis, specifically 2 finger breadths (3 cm) cephalad and 2 finger breadths medial to the anterior superior iliac spine. 1

• This site has thinner abdominal wall and larger fluid pool compared to the traditional midline approach 1
• Avoid the midline inferior epigastric arteries (located midway between pubis and anterior superior iliac spines) and visible collateral vessels 1
• The right lower quadrant may be suboptimal with dilated cecum from lactulose or appendectomy scar 1

Coagulation Parameters and Bleeding Risk

Do not routinely transfuse fresh frozen plasma or platelets before paracentesis, as bleeding complications are rare (0.2-2.2% of procedures). 1, 2

• In a study of 1,100 large-volume paracenteses, there were no hemorrhagic complications despite platelet counts as low as 19,000 cells/mm³ and INR as high as 8.7 1
• There is no data-supported cutoff of coagulation parameters beyond which paracentesis should be avoided 1
• The only contraindications are clinically evident fibrinolysis (three-dimensional ecchymosis/hematoma) or disseminated intravascular coagulation, which occur in less than 1 per 1,000 procedures 1

Volume Expansion for Large-Volume Paracentesis

For large-volume paracentesis removing >5L of ascitic fluid, administer intravenous albumin at 8g per liter of ascites removed to prevent circulatory dysfunction. 4, 3

• Paracentesis without plasma volume expansion consistently causes deterioration of effective circulating blood volume and may induce renal impairment and severe hyponatremia 5, 6
• Dextran 70 and polygeline appear as effective as albumin in preventing these abnormalities 5

Ascitic Fluid Analysis

For uncomplicated cirrhotic ascites, order only screening tests: cell count with differential, albumin, and total protein concentration. 1

Essential Tests for All Diagnostic Taps:

• Cell count and differential (automated counting is accurate and rapid) 1
• Albumin level to calculate SAAG (≥1.1 g/dL indicates portal hypertension with 97% accuracy) 1

Additional Tests Based on Clinical Suspicion:

• If infection suspected (fever, abdominal pain, unexplained encephalopathy): bacterial culture in blood culture bottles 1
• If peritoneal carcinomatosis suspected: cytology on 50 mL fresh warm fluid hand-carried to lab (sensitivity 82.8% first sample, 96.7% if three samples sent) 1
• If tuberculous peritonitis suspected (recent immigration from endemic area or AIDS): mycobacterial culture (sensitivity ~50%; smear sensitivity ~0%) 1
• If secondary bacterial peritonitis suspected: total protein, LDH, glucose, CEA (>5 ng/mL), and alkaline phosphatase (>240 units/L) to detect gut perforation 1

Outpatient Serial Paracentesis:

• Test only cell count and differential 1
• Bacterial culture not necessary in asymptomatic patients undergoing serial large-volume paracenteses 1

Post-Procedure Management

After therapeutic paracentesis, implement sodium restriction (88 mmol/day or 2000 mg/day) and oral diuretics to prevent fluid reaccumulation. 4, 3

• Start spironolactone 100 mg once daily as initial diuretic 4, 3
• Add furosemide 40 mg once daily if needed, maintaining a 100:40 mg ratio of spironolactone to furosemide 4, 3
• Increase doses simultaneously every 3-5 days if weight loss and natriuresis inadequate, up to maximum 400 mg/day spironolactone and 160 mg/day furosemide 4, 3

Critical Precautions

In patients with hepatic cirrhosis and ascites, initiate diuretic therapy in the hospital setting. 7, 8

• Sudden alterations of fluid and electrolyte balance may precipitate hepatic encephalopathy and coma in cirrhotic patients 7, 8
• Avoid NSAIDs entirely, as they reduce urinary sodium excretion, induce azotemia, and can convert diuretic-sensitive patients to refractory ascites 3
• Monitor serum electrolytes, creatinine, and weight regularly 4
• If serum sodium <120-125 mmol/L, implement fluid restriction 4, 3

Refractory Ascites Management

If ascites recurs rapidly or is unresponsive to maximum diuretic therapy (400 mg spironolactone + 160 mg furosemide with sodium restriction), perform serial therapeutic paracenteses every 2-3 weeks with albumin replacement. 4, 3