LUNG CARE SERVICE
Ultrasound-Guided Thoracentesis for Pleural Effusions
An ultrasound-guided thoracentesis is a procedure in which a needle is inserted through your chest wall into your lung cavity to remove or collect fluid accumulation (called a pleural effusion).
Doctors use thoracentesis to:
- relieve pressure on the lungs
- treat symptoms such as shortness of breath and pain
- determine the cause of excess fluid in the pleural space
How is the procedure performed?
A chest x-ray may be performed before a thoracentesis.
This procedure is often done on an outpatient basis. However, some patients may require admission following the procedure. Ask your doctor if you will need to be admitted.
The doctor or nurse will position you on the edge of a chair or bed with your head and arms resting on an examining table.
They will sterilize the area of your body where the needle is to be inserted and cover it with a surgical drape.
Your doctor will numb the area with a local anesthetic. This may briefly burn or sting before the area becomes numb.
The doctor inserts the needle through the skin between two ribs on your back. When the needle reaches the pleural space between the chest wall and lung, the doctor removes the pleural fluid through a syringe or suction device.
Thoracentesis usually takes about 15 minutes.
At the end of the procedure, the doctor will remove the needle and apply pressure to stop any bleeding. They will cover the opening in the skin with a dressing. No sutures are necessary.
If necessary, you may have a chest x-ray after thoracentesis to detect any complications.
Generally, once the procedure is completed, the patient is further educated about discharge instructions and is released to go home (as appropriate).
What does the equipment look like?
In this procedure, ultrasound, CT, or x-ray equipment may be used to guide a needle into the fluid within the pleural space. Thoracentesis is typically performed with ultrasound guidance. Occasionally, CT-guidance will be used.
Ultrasound machines consist of a computer console, video monitor and an attached transducer. The transducer is a small hand-held device that resembles a microphone. Some exams may use different transducers (with different capabilities) during a single exam. The transducer sends out inaudible, high-frequency sound waves into the body and listens for the returning echoes. The same principles apply to sonar used by boats and submarines.
The technologist applies a small amount of gel to the area under examination and places the transducer there. The gel enables sound waves to travel back and forth between the transducer and the area under examination. The ultrasound image is immediately visible on a video monitor. The computer creates the image based on the loudness (amplitude), pitch (frequency), and time it takes for the ultrasound signal to return to the transducer. It also considers what type of body structure and/or tissue the sound is traveling through.
The CT scanner is typically a large, donut-shaped machine with a short tunnel in the center. You will lie on a narrow table that slides in and out of this short tunnel. Rotating around you, the x-ray tube and electronic x-ray detectors are located opposite each other in a ring, called a gantry. The computer workstation that processes the imaging information is in a separate control room. This is where the technologist operates the scanner and monitors your exam in direct visual contact. The technologist will be able to hear and talk to you using a speaker and microphone.
A thoracentesis needle is generally several inches long and the barrel is about as wide as a large paper clip. The needle is hollow so fluid can be aspirated (drawn by suction) through it. In some instances, a small tube is advanced over the needle, and the fluid is removed through the tube after removing the needle.
What are the benefits vs. risks?
Thoracentesis is generally a safe procedure
No surgical incision is necessary
No scheduled appointment is necessary
Any procedure that penetrates the skin carries a risk of infection. The chance of infection requiring antibiotic treatment appears to be less than one in 1,000.