Parazentesis

Paracentesis, sometimes spelled parazentesis in some sources, is a medical procedure in which a needle or small catheter is inserted into the peritoneal cavity to withdraw ascitic fluid. It serves both diagnostic and therapeutic purposes, allowing analysis of the fluid and relief of symptoms from ascites.

Indications include new or unexplained ascites, evaluation for suspected infection such as spontaneous bacterial peritonitis, assessment for malignancy, and relief of abdominal distension or respiratory compromise from tense ascites.

Contraindications are generally relative and include uncorrected coagulopathy or very low platelets, local infection at the puncture site, or an inability to access fluid safely. Ultrasound guidance is commonly used to minimize risk.

The procedure is performed with sterile technique. After local anesthesia, ultrasound helps localize the fluid in the lower abdomen. A needle or catheter is inserted to aspirate ascitic fluid, which may be used for diagnostic testing. Fluid samples are typically analyzed for cell count and differential, Gram stain and culture, cytology, and chemistry, including the serum-ascites albumin gradient (SAAG) to help determine the cause of ascites.

For large-volume therapeutic paracentesis, intravenous albumin is often given to prevent circulatory dysfunction, typically 6 to 8 grams per liter of fluid removed when more than about 5 liters are withdrawn.

Complications include bleeding, infection, perforation or injury to abdominal organs, leakage at the puncture site, and transient hypotension. Risk is minimized with ultrasound guidance and careful technique. Follow-up includes monitoring for recurrence of symptoms and adjusting treatment for the underlying condition.