Paracentesis, or abdominal tapping, is a procedure to remove excess fluid from the area between the abdominal wall and the spine. This area is known as the abdominal cavity.
Excess fluid in the abdomen is called ascites. Usually, there should be no fluid within the abdominal cavity. Fluid in the abdominal cavity can cause bloating, pain, and breathing difficulties.
Paracentesis helps remove fluid from the abdominal cavity. It can also be used to help a doctor determine the cause of the fluid buildup.
The most common cause of ascites is cirrhosis, or fibrotic scarring of the liver. Fluid buildup in the abdominal cavity can also be caused by a variety of other conditions, including:
- bowel damage
- kidney disease
- heart failure
Before you have paracentesis, your doctor will take your medical history and give you a physical exam. They may also order other laboratory tests, such as blood tests.
Based on the hospital’s guidelines and your doctor’s recommendation, you may be asked to stop eating or drinking a few hours before the procedure.
You’ll also need to empty your bladder right before the procedure starts.
Paracentesis can be performed in the doctor’s office, a treatment room, or the hospital.
No general anesthesia is required. Paracentesis involves the following steps:
- The abdominal area is cleaned and shaved.
- The doctor applies a local anesthetic. This numbs the area to prevent any pain or discomfort. For larger fluid removal, your doctor may need to make a small cut in the skin to accommodate the needle.
- Once the area is ready, the doctor inserts a needle into the skin. The needle itself only goes 1 to 2 inches deep. Here, the fluid is extracted with a syringe.
- Your doctor removes the needle.
- Your doctor may or may not use ultrasound during paracentesis.
The amount of fluid removed depends largely on the original purpose of the procedure.
Your doctor may perform a small diagnostic tap, or they may perform a large-volume (or therapeutic) tap. During a large-volume tap, your doctor will remove several liters of fluid to decrease the pressure and pain. If this is the case, a catheter may be attached between the needle and syringe to help your doctor get more fluids.
After the procedure, your doctor will dress the wound and make any necessary stitches. If a diagnosis is needed, a bottle of the fluid will be submitted to a laboratory.
Risks associated with paracentesis are rare, but the most common risks are minor trouble breathing and fluid leakage right after the procedure. Usually, you’ll have to wait to leave the doctor’s office or hospital until those clear up.
Other risks include:
- a drop in blood pressure, which only occurs if a significant volume of fluid is removed
- accidental puncture of a blood vessel, the bowel, or the bladder
- acute kidney injury
Certain risk factors may also increase the chances of complications, especially if you have cirrhosis. You may also be more likely to develop an infection if you smoke or misuse alcohol on a regular basis. Poor nutrition can also increase the risk of infection.
Call your doctor immediately if you develop any of these symptoms once you’ve returned home:
- redness or swelling around the needle puncture site
- increased pain
- leakage of fluid
- shortness of breath
- chest pain
- increased abdominal swelling
Cirrhosis is the most common cause of abdominal fluid buildup. It causes
Other possible causes of this type of fluid retention are:
- abdominal injury
- bowel damage
- leakage of lymphatic fluid
- kidney disease
- liver disease
- heart disease
- pancreatic disease
- a tumor
- low levels of proteins in the blood
- internal bleeding
Depending on the results of the abdominal tap and any other test performed, you may need further medical care. Your doctor may recommend that you monitor your body weight to catch more fluid buildup.
Additional tests, such as ultrasounds, CT scans, and blood tests, may also need to be performed.
Recovery from the procedure is usually straightforward, and you’ll likely be able to resume normal activities once the wound heals. Check with your doctor about exercise and other physical activities after the procedure, especially if you have stitches.
Also, confirm with your doctor when it’s fine for you to resume eating and drinking. You may be asked to avoid alcohol after your procedure.
Excess fluid buildup in the abdominal cavity is atypical. Therefore, paracentesis is necessary to remove the fluids and determine the cause of buildup.
The outlook depends on the underlying cause of ascites. Depending on your condition, and if fluid continues to build up in your abdominal cavity, you may require multiple procedures in the future.
If ascites results in a severe decrease in liver function, then your doctor may recommend a liver transplant.