This information describes your thoracentesis procedure.

Thoracentesis is a procedure to remove fluid from the space between the chest wall and the lung. This space is called the pleural cavity. The procedure is done to make a diagnosis, to relieve symptoms, or both.

Before Your Procedure

Your doctor or nurse will tell you if you can eat food, drink liquids, and take your medication as usual.

You will have an x-ray (either a chest x-ray or a CT scan) to identify the exact location of the fluid around your lung. Sometimes, an ultrasound may be done in addition to the x-ray. It may help to get a better image of the fluid's location.

During Your Procedure

Most commonly, you will be placed in a sitting position. An antiseptic solution will be applied to an area of your back. It will feel cool. Your doctor will then inject a small part of this area with a local anesthetic. When the area is numb, a needle will be inserted into your pleural cavity. The fluid will be removed through this needle. You may feel an urge to cough. It is important that you try not to move while the needle is in place.

Your oxygen level and heart rate may be monitored during the procedure. You may feel discomfort or pain in your shoulder. This is more likely towards the end of the procedure. If you have pain, tell your doctor.

After the fluid is removed, it may be sent to the lab for analysis. Your doctor will have most of the final results in about 2 business days.

After Your Procedure

  • The needle may be left in place for a few hours to allow more fluid to drain. Ask your doctor what to expect. When it is removed, a small bandage (e.g., Band-Aid®) will be placed over the area. It is not unusual for a small amount of fluid to leak from the procedure site for a short while. Your nurse will give you extra gauze to protect your clothing in case this happens. You can take the bandage off in 24 hours.
  • When your procedure is completed, you will be sent for an x-ray of your chest to make sure your lung is expanding.
  • You may feel some discomfort. Ask your doctor about taking pain medication.
  • You may resume your normal activities.

Call Your Doctor or Nurse if You Develop:

  • Severe or worsening shortness of breath
  • Increased pain on the side of your procedure
  • A temperature of 101° F (38.3° C) or higher
  • Shaking chills