Peritoneal fluid culture

The peritoneal space is the area between the abdominal wall and the organs it houses. This space is typically empty, or contains a small amount of fluid. But a buildup of fluid can occur if you have a disease or infection. This fluid is called ascites.

Inflammation of the lining of the abdominal wall, or the peritoneum, can also occur. This can cause pain, nausea, vomiting, and constipation. If left untreated, it can be life-threatening. It can be caused by a variety of diseases, which your doctor can diagnose and treat.

A peritoneal fluid culture is a test that is performed on a small sample of peritoneal fluid. It may also be called an abdominal tap or paracentesis. The laboratory examines the fluid for any bacteria or fungi that may be causing an infection.

When your peritoneum is inflamed, it’s typically because bacteria or fungi have entered the peritoneal space by blood and lymph nodes. Peritonitis means that the peritoneum is inflamed. More commonly, infection spreads to the peritoneal space from your biliary or gastrointestinal tract. This is called secondary peritonitis.

Risks for developing peritonitis include:

Peritonitis can be dangerous, causing sepsis and lung infections. Sepsis is an infection in the body caused by a reaction to bacteria that are present. If there’s a large amount of fluid in your peritoneum, it can cause abdominal pain. Large amounts of fluid may be removed to ease discomfort.

In order to treat peritonitis, the underlying cause needs to be determined. A peritoneal fluid culture can help make a diagnosis.

You don’t have to do anything special for this procedure, other than follow your doctor’s instructions. If necessary, the area will be shaved prior to the insertion of the needle.

Tell your doctor if you:

  • are allergic to any numbing medication or other drugs
  • have a bleeding disorder
  • are taking any medications or supplements, including herbal medications and over-the-counter drugs
  • are pregnant or think you might be pregnant

A peritoneal fluid culture can be performed in your doctor’s office or a hospital. You’ll be asked to empty your bladder before the procedure. A spot on your lower abdomen will be cleaned with an antiseptic, and you will receive local anesthesia to numb the area.

A needle will be inserted 1 to 2 inches into your abdominal cavity. A small incision may be necessary if there is difficulty inserting the needle. Fluid is removed through a syringe.

During the procedure, you might feel pressure. If a lot of fluid is being removed, dizziness or lightheadedness is not uncommon. If you feel discomfort or dizziness, tell your doctor.

You’ll be asked to sign a consent form before the procedure. There’s a small chance of leaking fluid after the procedure. The bowel, bladder, or an abdominal blood vessel can also be punctured, but this is rare. As with all invasive procedures, there’s also a risk of infection.

Once the culture is done, it’s sent to a laboratory where a Gram’s stain and culture are performed. A Gram’s stain is used to show the differences in the types of bacteria. Abnormal results might show:

  • cirrhosis
  • heart disease
  • pancreatic disease
  • a damaged bowel
  • an infection

Once your doctor gets the results, they can start treating the underlying condition. In some cases, additional follow-up tests may be needed.