What is the term for removal of fluid from the abdomen?

Paracentesis: Removal of Fluid from the Abdomen

The removal of fluid from the abdomen is called paracentesis. This medical procedure involves the percutaneous drainage of ascitic fluid from the peritoneal cavity using a needle or catheter 1.

Types of Paracentesis

Paracentesis can be performed for different purposes:

1. Diagnostic paracentesis: Small volume (typically 20-50 mL) removal of ascitic fluid for laboratory analysis
2. Therapeutic paracentesis: Large volume removal of ascitic fluid to relieve symptoms
   • Small volume: <5 liters
   • Large volume: ≥5 liters

Procedure Technique

The procedure is performed under strict sterile conditions 1:

• Patient is typically positioned in a supine position
• Ultrasound guidance is recommended to reduce risk of adverse events 1
• The preferred insertion site is the left lower quadrant (8 cm from midline, 5 cm above symphysis) 1
• A "Z-track" technique is used:
  • Skin is penetrated perpendicularly
  • Needle is advanced obliquely in subcutaneous tissue
  • Peritoneal cavity is punctured with needle perpendicular to abdominal wall
• Multiple side-perforated cannula is preferred to prevent blockage 1
• Fluid is drained to dryness in a single session over 1-4 hours 1

Volume Expansion After Large Volume Paracentesis

For large volume paracentesis (>5 liters), plasma volume expansion is essential 1:

• Recommended: 8g albumin per liter of ascites removed (typically as 20% or 25% solution) 1
• Albumin is preferred over synthetic plasma expanders as it:
  • Results in less activation of the renin-angiotensin-aldosterone system
  • Has lower rates of hyponatremia (8% vs 17%)
  • Is associated with fewer liver-related complications

Clinical Applications

Paracentesis is used in various clinical scenarios:

1. Management of ascites in cirrhosis 1:

   • First-line treatment for large or refractory ascites
   • Relieves symptoms of tense abdomen

2. Management of intra-abdominal hypertension (IAH) and abdominal compartment syndrome (ACS) 1, 2:

   • Percutaneous catheter drainage (PCD) is recommended when intraperitoneal fluid is present
   • Can prevent need for decompressive laparotomy

3. Diagnostic purposes 3:

   • Evaluation of peritonitis
   • Assessment of hemoperitoneum
   • Investigation of uroabdomen
   • Diagnosis of malignancy

Potential Complications

Complications are relatively rare but include 1, 4:

• Bleeding (0-2.7%)
• Ascitic fluid leak (0-2.35%)
• Bowel perforation (0.83%)
• Infection/peritonitis (risk increases with indwelling catheters left >3 days) 5
• Severe hemorrhage (<0.2%)
• Death (<0.02% directly related to procedure)

Important Considerations

• Routine measurement of prothrombin time and platelet count before paracentesis is not recommended 1
• Ultrasound guidance should be considered to reduce adverse events 1
• After paracentesis, patients should lie on the opposite side for 2 hours if leakage occurs 1
• A purse-string suture around the drainage site can minimize fluid leakage 1

Paracentesis is a valuable procedure that provides both diagnostic information and therapeutic benefit with minimal risk when performed properly with appropriate precautions.