How do I perform a paracentesis on an adult patient with clinically significant ascites?

How to Perform Paracentesis

Perform paracentesis in the left lower quadrant, 2 finger breadths (3 cm) cephalad and 2 finger breadths medial to the anterior superior iliac spine, using sterile technique without routine prophylactic correction of coagulopathy. 1

Site Selection

The left lower quadrant is the preferred location for paracentesis because the abdominal wall is thinner and the pool of ascitic fluid is deeper compared to the traditional midline approach 1. The specific landmark is 2 finger breadths (3 cm) cephalad and 2 finger breadths medial to the anterior superior iliac spine 1.

Avoid these areas:

• The inferior epigastric arteries (located midway between the pubis and anterior superior iliac spines, running cephalad in the rectus sheath) 1
• Visible collateral vessels on the abdominal wall 1
• The right lower quadrant if there is a dilated cecum (from lactulose) or appendectomy scar 1
• Areas with surgical scars or distended bowel 2

Pre-Procedure Considerations

Coagulopathy Management

Do not routinely transfuse fresh frozen plasma or platelets before paracentesis 1. This is a Class III recommendation based on evidence showing:

• No hemorrhagic complications in 1,100 large-volume paracenteses despite platelet counts as low as 19,000 cells/mm³ (54% had counts <50,000) and INR as high as 8.7 (75% had INR >1.5,26.5% had INR >2.0) 1
• Bleeding complications occur in less than 1/1000 procedures 1
• Routine coagulation tests do not reflect actual bleeding risk in cirrhosis due to balanced deficiency of procoagulants and anticoagulants 1

Absolute contraindications (paracentesis should be prohibited):

• Clinically evident hyperfibrinolysis (three-dimensional ecchymosis/hematoma) 1, 2
• Clinically evident disseminated intravascular coagulation 1, 2

Relative contraindications requiring caution:

• Severe renal dysfunction (8 of 9 bleeding complications occurred in patients with renal failure in one study) 1
• Pregnancy 2
• Severe intestinal distension 2
• Extensive abdominal surgery history 2

In these relative contraindication cases, ultrasound guidance can be helpful 2.

Procedure Technique

For Diagnostic Paracentesis:

• Withdraw 10-20 mL of ascitic fluid using a syringe with a blue or green needle 3
• Immediately inoculate at least 10 mL into blood culture bottles at the bedside (increases culture sensitivity from ~50% to ~80-90%) 1, 4, 5
• Send samples for cell count with differential in an EDTA tube 3

For Therapeutic (Large-Volume) Paracentesis:

• Use a 15-gauge, 3.25-inch needle-cannula system (results in fewer multiple peritoneal punctures and less termination due to poor fluid return compared to 14-gauge needles) 5
• A peritoneal dialysis catheter system is safe and effective for removing large volumes (mean 7.6 L in 129 minutes) 6
• The left lower quadrant remains the most common and preferred site 6

Post-Procedure Management

Volume Expansion Guidelines:

For paracentesis <5 liters:

• Use synthetic plasma expanders (150-200 mL of gelofusine or haemaccel) 3
• Albumin is not required 3

For large-volume paracentesis (≥5 liters):

• Administer 8 g albumin per liter of ascites removed once paracentesis is complete 3, 1
• This equals approximately 100 mL of 20% albumin per 3 liters of ascites removed 3
• Failure to give volume expansion can lead to post-paracentesis circulatory dysfunction with renal impairment and electrolyte disturbances 3

The 5% albumin solution (available in the US) increases sodium load five-fold compared to 20% solution and should be used cautiously 1.

Indications for Paracentesis

Diagnostic paracentesis should be performed in: 2, 1, 7

1. All patients with new-onset Grade 2 or 3 ascites
2. All patients hospitalized for worsening ascites
3. Any cirrhotic patient with complications including fever, abdominal pain, GI bleeding, hepatic encephalopathy, hypotension, or renal insufficiency
4. All hospitalized cirrhotic patients with ascites (to rule out spontaneous bacterial peritonitis, even without symptoms)

Timing matters: Paracentesis within 12-24 hours of admission is associated with lower hospital mortality 7.

Complications and Management

Severe hemorrhage occurs in 0.2-2.2% of procedures, with a death rate of 0.02% (1 in 4,729 procedures) 2. Bleeding can occur from:

• Superficial abdominal wall veins (superficial epigastric vein)
• Mesenteric varices
• Intraperitoneal collateral vessels (paraumbilical vein)
• Inferior epigastric artery or deep circumflex iliac artery 2

Symptoms typically appear within 6-24 hours but can be delayed up to 1 week 2.

Management of bleeding:

• Most cases: fluid resuscitation, transfusion, correction of coagulation disorders 2
• Persistent hemodynamic instability: transcatheter coil embolization or laparoscopy with vessel ligation 2
• Severe bleeding: consider TIPS or liver transplantation 2

The most common minor complication is self-limited ascitic fluid leak at the puncture site 6.