Paracentesis is a common medical procedure involving the removal of excess fluid (ascites) that has accumulated within the abdominal cavity, specifically in the peritoneal cavity. The procedure uses a thin needle or catheter to safely drain the fluid. Routinely performed by trained physicians or advanced practice providers, it is a safe and quick intervention used either for diagnosis or to provide symptom relief.
Indications: Why Abdominal Fluid Needs Draining
Physicians perform paracentesis for one of two primary purposes: diagnosis or therapy.
A diagnostic paracentesis involves removing a small fluid sample, typically around 25 to 50 milliliters, for laboratory analysis. This testing is performed to determine the underlying cause of fluid buildup, which can be linked to conditions like liver failure, heart failure, or certain cancers. The test is particularly important for ruling out spontaneous bacterial peritonitis (SBP), an infection of the fluid itself. Prompt identification of SBP is critical, as delayed treatment significantly increases the risk of complications.
A therapeutic paracentesis drains large volumes of fluid, sometimes five liters or more, to alleviate physical discomfort. This large-volume drainage relieves the severe abdominal pressure, pain, and difficulty breathing caused by massive ascites. Although the fluid may reaccumulate, the procedure offers immediate, palliative relief from the symptoms.
Patient Experience: Preparation and Execution
Preparation involves several steps to ensure safety and comfort. The patient is asked to empty their bladder completely to prevent accidental puncture. They are typically positioned lying on their back with the head slightly elevated or sometimes on their side to allow the fluid to collect. The medical team also obtains informed consent, ensuring the patient understands the procedure.
The insertion site, often in the lower abdomen, is thoroughly cleaned with an antiseptic solution to prevent infection. A local anesthetic, such as lidocaine, is injected into the skin and deeper abdominal wall layers, which may cause a brief sting. Ultrasound imaging is routinely used to pinpoint the largest pocket of fluid and to carefully avoid blood vessels or the bowel.
Once the area is numb, the physician inserts a specialized needle or catheter into the peritoneal cavity. Patients may feel pressure during this step, but typically not sharp pain. For therapeutic procedures, the catheter connects to a drainage system, and the fluid drains over 20 to 60 minutes, depending on the volume. The Z-track method, where the skin is pulled slightly before insertion, is often used to reduce the risk of fluid leakage afterward.
Post-Procedure Care and Monitoring
Immediately following drainage, the needle or catheter is removed, and a small sterile dressing is placed over the puncture site. Nursing staff monitor the patient’s vital signs, including blood pressure and heart rate, to ensure stability, especially after large-volume removal. If more than five liters of fluid were removed, an intravenous infusion of albumin may be given to prevent a sudden drop in blood pressure and circulatory dysfunction.
Home care instructions focus on site maintenance and recognizing potential complications. The dressing should remain in place for 24 hours, after which the patient can shower and gently wash the area. Light activity is permitted, but strenuous exercise should be avoided for a day or two. Patients should monitor the puncture site for excessive fluid leakage, which usually resolves on its own.
Recognizing signs that require immediate medical attention is a key part of post-procedure monitoring. These signs include a fever above 100.4°F (38.0°C) or chills, which may indicate an infection. Other concerning symptoms are severe abdominal pain that worsens, or significant bleeding, redness, or warmth at the insertion site. Promptly contacting a provider ensures that any complication can be addressed quickly.