How should I safely perform a diagnostic and therapeutic paracentesis for ascites in a cirrhotic patient, including contraindications, technique, volume limits, and albumin replacement?

How to Perform Ascitic Tap (Paracentesis)

Paracentesis in cirrhotic patients should be performed with ultrasound guidance when available, without routine correction of coagulopathy, and followed by albumin replacement at 8 g per liter for volumes exceeding 5 L. 1

Pre-Procedure Assessment

Informed Consent and Laboratory Testing

• Obtain informed consent before any paracentesis procedure. 1, 2
• Do not routinely measure PT/INR or platelet count before paracentesis, and do not transfuse blood products prophylactically. 1 Bleeding complications occur in less than 1 in 1,000 procedures even with significant coagulopathy. 2
• Paracentesis can be safely performed with INR up to 8.7 and platelets as low as 19×10³/μL. 3
• The only absolute contraindication is disseminated intravascular coagulation; loculated ascites is a relative contraindication. 4, 2

Site Selection

• Insert the needle in the left lower quadrant (preferred site), approximately 2 finger breadths cephalad and 2 finger breadths medial to the anterior superior iliac spine. 2
• Alternative site: right lower quadrant, at least 8 cm from midline and 5 cm above symphysis pubis. 3, 4
• Avoid the epigastric vessels that run laterally from the umbilicus toward the mid-inguinal point. 4

Procedural Technique

Equipment and Approach

• Use strict sterile technique with disposable sterile equipment. 4
• Ultrasound guidance should be used when available to reduce adverse events, particularly in patients with obesity, pregnancy, severe intestinal distension, or prior abdominal surgery. 1, 2
• Use the "Z-track" technique: perpendicular skin entry with oblique subcutaneous advancement. 3
• Use a cannula with multiple side perforations to prevent blockage by bowel wall. 3

Drainage Protocol

• Perform complete drainage to dryness in a single session over 1–4 hours; there is no absolute upper volume limit when albumin replacement is provided. 3
• Typical drainage rate is 2–9 liters per hour. 3
• Do not artificially slow the drainage rate out of concern for hemodynamic instability—this outdated practice delays symptom relief without improving safety. 3
• Do not leave the drainage catheter in place overnight. 3

Fluid Collection for Diagnostic Testing

• For diagnostic paracentesis, withdraw 10–20 mL of ascitic fluid. 2
• Inoculate at least 10 mL into aerobic and anaerobic blood culture bottles at the bedside immediately to maximize detection of spontaneous bacterial peritonitis. 4, 2
• Send fluid for cell count with differential (neutrophil count ≥250 cells/mm³ is diagnostic of SBP), albumin (to calculate SAAG), and culture. 4, 2

Post-Procedure Management

Albumin Replacement

• For paracentesis >5 L: mandatory albumin replacement at 8 g per liter of ascites removed (e.g., 100 mL of 20% albumin per 3 L removed). 1, 3 This is a high-quality, strong recommendation. 1
• Infuse albumin after paracentesis is completed, not during the procedure, over 1–2 hours. 3
• For paracentesis <5 L: albumin replacement is not mandatory in uncomplicated cases but should be considered in patients with acute-on-chronic liver failure or high risk of post-paracentesis acute kidney injury. 1, 3

Clinical rationale: Albumin prevents post-paracentesis circulatory dysfunction (PICD), reducing the odds of PICD by 60%, hyponatremia by 42%, and mortality by 36% compared to alternative volume expanders. 3, 5 Without albumin, renal impairment occurs in approximately 21% of patients versus 0% with albumin. 3

Diuretic Therapy

• After large-volume paracentesis, diuretic therapy is required to prevent re-accumulation of ascites. 3
• Initiate or resume spironolactone 100–400 mg/day combined with furosemide 40–160 mg/day in a 100:40 mg ratio. 3
• Advise dietary sodium restriction to 88–90 mmol/day (approximately 5–5.2 g salt/day or 2000 mg sodium/day). 4

Monitoring

• Monitor for PICD over the subsequent 6 days: check plasma renin activity (>50% rise from baseline), daily serum creatinine (for acute kidney injury), and daily serum sodium (for hyponatremia). 3

Common Pitfalls to Avoid

• Never withhold paracentesis due to coagulopathy or thrombocytopenia—routine correction of INR or platelet count wastes resources and exposes patients to unnecessary transfusion risks. 4, 2
• Never perform large-volume paracentesis (>5 L) without albumin replacement—this consistently causes circulatory dysfunction and increases mortality risk. 2
• Never delay antibiotic therapy while waiting for culture results if neutrophil count is ≥250 cells/mm³—empiric treatment with third-generation cephalosporins must be started immediately. 4, 2
• Avoid NSAIDs, ACE inhibitors, angiotensin-II receptor blockers, α₁-adrenergic blockers, and aminoglycosides in patients with ascites, as these medications worsen renal function and ascites control. 3

Special Considerations

• Development of ascites is an indication for liver transplantation evaluation, reflecting a poor prognosis with approximately 50% two-year survival. 3, 4
• Patients requiring frequent paracentesis (≥2–3 times per month) should be evaluated for transjugular intrahepatic portosystemic shunt (TIPS) if otherwise suitable. 1, 3