What is the procedure for performing a paracentesis?

From the Guidelines

Paracentesis should be performed by inserting a needle or catheter into the left lower quadrant of the abdomen, 2-3 cm below the umbilicus and lateral to the rectus muscle, using sterile technique and local anesthesia, and removing the desired amount of fluid, with intravenous albumin administration during large-volume paracentesis to prevent circulatory dysfunction, as recommended by the most recent guidelines 1. The procedure for performing a paracentesis involves several key steps, including:

• Patient positioning in a semi-recumbent position with the head of the bed elevated 30-45 degrees
• Selection of the site, usually in the left lower quadrant of the abdomen, avoiding surgical scars and visible blood vessels
• Sterilization of the area with chlorhexidine or povidone-iodine solution and draping
• Administration of local anesthesia with 1-2% lidocaine subcutaneously and into deeper tissues
• Insertion of a paracentesis needle or catheter (typically 18-22 gauge) perpendicular to the skin and advanced slowly through the abdominal wall
• Connection of the needle to a syringe or vacuum bottle for fluid collection
• Removal of the desired amount of fluid, with 50-100 mL usually sufficient for diagnostic purposes and several liters for therapeutic paracentesis
• Administration of intravenous albumin (6-8 g per liter of fluid removed) during large-volume paracentesis (>5 liters) to prevent circulatory dysfunction, as supported by studies 1
• Monitoring of the patient for complications, including hypotension, bleeding, infection, or bowel perforation
• Contraindications for the procedure include severe coagulopathy, thrombocytopenia, or skin infection at the insertion site, with caution exercised in patients with severe coagulopathy and loculated ascites, as noted in the guidelines 1.

From the Research

Procedure for Performing a Paracentesis

The procedure for performing a paracentesis involves several steps, including:

• Identifying the optimal location for the procedure, with the left lower quadrant (LLQ) being preferred due to its thinner abdominal wall and deeper amount of fluid 2
• Using ultrasound guidance to reduce the risk of serious complications, such as bleeding, and to improve the success rates of the procedure 3
• Assessing the volume and location of intraperitoneal free fluid to guide clinical decision making and to avoid attempting paracentesis in patients with an insufficient volume of fluid 3
• Evaluating the needle insertion site using color flow Doppler ultrasound to identify and avoid abdominal wall blood vessels along the anticipated needle trajectory 3
• Marking the needle insertion site with ultrasound immediately before performing the procedure and having the patient remain in the same position between marking the site and performing the procedure 3

Key Considerations

Some key considerations when performing a paracentesis include:

• The amount of fluid to be removed, with the removal of at least 5L of ascitic fluid considered large-volume paracentesis 4
• The potential risks and complications of the procedure, including bleeding and infection, although these are relatively rare 5
• The importance of monitoring the patient throughout the procedure and administering treatment as directed by the medical team 4
• The role of the nurse in providing safe and effective care for patients undergoing paracentesis, including educating patients about the procedure and its potential risks and benefits 4

Location for Paracentesis

The optimal location for paracentesis has been studied, with the LLQ being preferred due to its thinner abdominal wall and deeper amount of fluid 2. The classic site for paracentesis in generalized ascites is in the left lower quadrant of the abdomen at a position equivalent to McBurney's point, although this site has an average success rate of only 58% 6. Ultrasound guidance can help to improve the success rates of the procedure and reduce the risk of complications 3.