Peritoneal fluid is a fluid made by the peritoneum in the abdominal cavity which lubricates the surface of tissue that lines the abdominal wall and pelvic cavity. It covers most of the organs in the abdomen. An increased volume of peritoneal fluid is called ascites. A sampling of peritoneal fluid is generally performed by paracentesis. Peritoneal fluid microscopy is a useful test in evaluating the cause of ascites. 

Causes of Ascites

Cirrhosis is the most common cause of ascites. 

Other conditions that can cause it to include heart failure, kidney failure, infection, or cancer.

Symptoms of Ascites

The main symptoms of ascites are a large belly and rapid weight gain.

Other symptoms include:

  • Swelling in ankles.
  • Shortness of breath.
  • Digestive issues such as: bloating, abdominal pain, loss of appetite, indigestion, and constipation.
  • Back pain.
  • Difficulty sitting.
  • Fatigue.

How to collect the sample of Peritoneal or Ascites fluid?

  • Paracentesis generally takes about 20 to 30 minutes. 
  • It can be performed lying on the back or sitting up, depending on the amount of fluid that needs to be collected. 
  • For larger volumes of fluid, have to lie on the back.
  • After sanitizing the abdomen, drape it with a sterile towel and apply numbing medicine where the needle will enter the abdominal cavity.
  • If a larger volume of fluid needs to be collected, the paracentesis needle may be hooked by a narrow tube to a vacuum bottle for the fluid to drain.
  • Gently insert the needle into the abdomen and remove up to 4 liters of fluid. 
  • If more than 4 liters need to be collected, give supplemental fluids through an IV to prevent low blood pressure. 
  • After collection of fluid, remove the needle and bandage the entry site. 
  • The pulse, blood pressure, and temperature will be monitored over the course of an hour to ensure that vital signs are normal or abnormal for the patient.