What are the diagnostic studies for paracentesis (percutaneous abdominal fluid aspiration)?

From the Guidelines

For paracentesis, essential studies include total protein concentration and calculation of the serum ascites albumin gradient (SAAG), as recommended by the most recent guidelines 1. The initial ascitic fluid analysis should include these tests to diagnose spontaneous bacterial peritonitis (SBP) and determine the cause of ascites.

• A SAAG ≥1.1 g/dL suggests portal hypertension, while <1.1 g/dL indicates non-portal hypertension causes.
• Additional tests may include cytology for suspected malignancy, amylase if pancreatic ascites is suspected, and triglycerides for chylous ascites, based on pre-test probability of specific diagnosis 1.
• The left lower quadrant is the preferred location for paracentesis due to the greater depth of ascites and the thinner abdominal wall, with a low risk of severe hemorrhage (0.2-2.2%) and death (rare) 1.
• Routine prophylactic use of fresh frozen plasma or platelets before paracentesis is not generally recommended, unless there is clinically evident hyperfibrinolysis or disseminated intravascular coagulation 1.
• Paracentesis should be performed in all patients with new-onset ascites, hospitalized for worsening ascites, or with any complication of cirrhosis, including fever, abdominal pain, gastrointestinal bleeding, hepatic encephalopathy, hypotension, or renal insufficiency 1.

From the Research

Diagnostic Studies for Paracentesis

The diagnostic studies for paracentesis, also known as percutaneous abdominal fluid aspiration, involve various procedures to guide the safe and effective removal of ascitic fluid from the abdominal cavity.

• Ultrasound guidance is recommended to reduce the risk of serious complications, such as bleeding, and to improve the success rates of the procedure 2.
• Ultrasound should be used to assess the volume and location of intraperitoneal free fluid, guide clinical decision making, and identify a suitable needle insertion site based on the size of the fluid collection, thickness of the abdominal wall, and proximity to abdominal organs 2.
• Color flow Doppler ultrasound should be used to evaluate the needle insertion site and avoid abdominal wall blood vessels along the anticipated needle trajectory 2.
• Real-time ultrasound guidance should be considered when the fluid collection is small or difficult to access 2.

Complications and Risks

The complications and risks associated with paracentesis include:

• Bleeding, which is uncommon and usually mild, even in patients with marked thrombocytopoenia or prolongation of prothrombin time 3.
• Infections, which can occur in patients with cirrhosis, particularly those with low platelet count, Child-Pugh stage C, and alcoholic cirrhosis 4.
• Technical problems, such as leak of ascites at the puncture site, which can occur in up to 5.6% of procedures 4.
• Serious harm, including fatal bowel perforation, which can occur in rare cases 5.

Patient Care and Monitoring

Nurses play a crucial role in providing safe and effective care for patients undergoing paracentesis, including:

• Monitoring the patient throughout the procedure and administering treatment as directed by the medical team 6.
• Removing the drain at the end of the procedure, depending on local policy 6.
• Educating patients about the benefits and risks of the procedure and providing evidence-based care 6.