The fluid that is removed from the pleural space during this procedure can be used for diagnostic purposes, or it can be done to relieve shortness of breath. Occasionally, pleurodesis, a procedure to introduce an irritant, like talc into the drained pleural space to stop fluid buildup from recurring, will be performed as part of the thoracentisis.
How is Thoracentisis Performed?
This type of mesothelioma surgery can be performed on an outpatient basis. Before the thoracentisis, the doctor will confirm the location of the fluid through the use of a physical examination and a chest x-ray. However, the patient may also need to undergo a CT scan and/or an ultrasound if a previous thoracentisis attempt failed, or if the fluid is loculated, meaning it is trapped inside little pockets of tissue.
The patient is usually sitting upright and leaning slightly forward with a support under the arms. A local anesthetic called lidocaine is injected into the skin to anesthetize it. Another needle containing more lidocaine is injected into the upper border of the rib that is one intercostals space below the fluid. An intercostals space is the space between two ribs.
The lidocaine is injected in intervals, as the needle goes more deeply into the chest. The major portion of the anesthetic is injected into the parietal pleura, the part of the pleura that lines the chest wall. The needle is moved past the parietal pleura until fluid is aspirated.
A thoracentesis needle combined with catheter is attached to a 3-way stopcock. A stopcock is a special valve that controls the flow of liquid. The needle-stopcock is attached to a 30- to 50-mL (milliliter) syringe and tubing. The needle is moved through the skin into tissue along the upper border of the rib that is just below the fluid until it reaches the fluid buildup. The catheter is inserted through the needle, and the needle is removed.
As the fluid is drained, the stopcock is used to stop/start the flow so that the fluid can be collected in different receptacles to be evaluated later. The fluid can only be removed at a rate of 1.5 liters per session. If it is removed at any faster rate, it could cause low blood pressure or a buildup of fluid in the air sacs in the lungs.
The thoracentisis is usually followed by a chest x-ray to be sure the patient does not have pneumothorax, a condition in which air from the lungs leaks into the pleural cavity and compresses the lung. The x-ray is also used as an indication of how much fluid was removed and to look at the areas of the lung’s surface that were hidden by the fluid.
Coughing is a common side effect of this mesothelioma surgery. It typically occurs when the lung re-expands after the thoracentisis. If the two layers of the pleura are inflamed, the patient may also experience pain and hear a rubbing sound as the fluid is drained because the inflammation has enlarged the parietal and visceral pleura so much that they are now touching.