Thoracentesis
Thoracentesis, also known as thoracocentesis or pleural tap, is a medical procedure that involves the removal of pleural fluid from the space between the layers of the pleura, which line the lungs and chest cavity. This is typically done using a needle inserted through the chest wall to analyze the fluid for diagnostic purposes, primarily to understand the causes of pleural effusions, where excess fluid accumulates abnormally. Thoracentesis can serve both diagnostic and therapeutic roles; it helps alleviate symptoms such as shortness of breath by removing excess fluid that exerts pressure on the lungs.
Preparation for the procedure includes imaging tests like chest X-rays and possibly ultrasounds to locate the effusion, along with blood tests to check for clotting issues. During the procedure, the patient is usually seated upright, and a local anesthetic is administered to minimize discomfort. Risks associated with thoracentesis include potential complications like bleeding, infection, or pneumothorax, although these are generally rare when ultrasound guidance is utilized.
After fluid removal, the sample is analyzed to identify conditions such as infections, cancer, or heart failure. Patients often experience symptom relief shortly after the procedure, but if the effusion recurs, additional interventions may be necessary. Recent advancements in thoracentesis techniques and tools aim to enhance effectiveness and patient comfort, underscoring the ongoing evolution of this important medical procedure.
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Subject Terms
Thoracentesis
ALSO KNOWN AS: Thoracocentesis, pleural tap
DEFINITION: Thoracentesis is the removal of pleural fluid from the layers of the pleura, the membranes lining the lungs and chest cavity. The pleural fluid is removed through a needle inserted through the chest wall between the ribs and is analyzed in a laboratory to determine the underlying cause of the fluid accumulation.
Cancers diagnosed or treated:Lung cancer, breast cancer, lymphoma, leukemia
Why performed: A thoracentesis is performed as a diagnostic procedure to determine the cause of a pleural effusion, the abnormal collection of excess fluid between the layers of the pleura. Normally, only a small amount of fluid is present in the pleural cavity to lubricate the pleural surfaces. This procedure is also performed as a therapeutic procedure to remove excess fluid and help reduce pressure on the lungs when an effusion is large and causing symptoms such as shortness of breath or other breathing problems. A thoracentesis may be used as a palliative treatment to relieve symptoms of advanced cancers.
Patient preparation: Tests performed before the procedure include a chest X-ray to confirm the presence of the pleural effusion and identify its location, ultrasound of the chest, and blood tests, such as a complete blood count, to exclude any blood-clotting abnormalities. One week before the procedure, patients must stop taking aspirin and products containing aspirin, ibuprofen, and anticoagulants, as directed by the physician. Other medications may be prescribed, if necessary, before the procedure. There are no specific eating or drinking guidelines in preparation for a thoracentesis.
Steps of the procedure: The patient usually sits upright on the edge of a chair or bed, with the head and arms resting on a table. Sedating medications are not usually given for this procedure. The skin around the procedure site between the ribs and back of the chest is cleansed, and sterile drapes are placed around the area. A local anesthetic is injected into the skin to numb the area. The thoracentesis needle is inserted into the pleural space. Ultrasound guidance may be used to direct the needle into the effusion. Fluid is withdrawn through a syringe attached to the biopsy needle and collected for analysis in the laboratory.
Sclerosing agents such as talc, doxycycline, bleomycin, and quinacrine may be inserted through a chest tube during thoracentesis to prevent recurring, symptomatic effusions.
The patient may experience mild pain or discomfort at the puncture site. The patient should not cough or breathe deeply during the procedure and must remain as still as possible to prevent injury to the lung. If the patient develops a cough or chest pain during the procedure, then the procedure should be stopped immediately.
After the procedure: Pressure is applied at the site where the needle was inserted. A dressing or adhesive bandage is placed over the site to help prevent infection. Supplemental oxygen may be given to the patient. The patient’s breathing will be monitored after the procedure. A chest X-ray is performed to ensure that the lung was not injured during the procedure. The patient should immediately report chest pain, shortness of breath, or difficulty breathing to the nurse. After the patient goes home within a few hours of the procedure, they should seek emergency treatment if these symptoms occur. A follow-up chest X-ray may be scheduled within two to four weeks.
Risks: The risks of a thoracentesis are decreased when the procedure is performed with ultrasound guidance. In most cases, there are few complications. The risks, however, include reaccumulation of fluid in the pleural space or fluid in the lungs (pulmonary edema), bleeding, infection, respiratory distress, or collapse of the lung (pneumothorax). Pneumothorax occurs when air has built up in the pleural space because of a leak in the lung. Pneumothorax often does not require treatment, but in some cases, it may require placement of a chest tube thoracostomy, a procedure to drain air from the space around the lungs to allow the lung to reexpand. Rarely, damage to the spleen or liver may occur as a result of a puncture from the thoracentesis needle.
Results: The fluid sample that was removed during the procedure is first examined for color and consistency by the physician and is then analyzed in a laboratory. The fluid may be exudative (protein-rich) or transudative (watery, protein-poor). Pleural fluid analysis is useful in determining the cause of the effusion, such as infection, pneumonia, blood in the pleural space (hemothorax), cancer, heart failure, cirrhosis, or kidney disease. It may also help identify other conditions, such as pancreatitis, pulmonary embolism, or thyroid disease. The goals of therapeutic thoracentesis include draining excess fluid, treating infection, fully reexpanding the lung, and relieving symptoms such as shortness of breath, chest pain, or dry cough. If a large amount of fluid was removed, then the patient will experience a relief of symptoms soon after the procedure.
If the effusion reaccumulates, a repeat thoracentesis procedure may be needed, which often occurs when the underlying cause is a malignancy. In patients with reoccurring fluid buildup due to malignancy, catheters like the PleurX have been developed, allowing continued fluid drainage at home. Further, advances have been made in thoracentesis in the twenty-first century. Patients have benefitted from new catheter and needle designs that reduce pain and increase efficiency. Doctors have benefitted from training simulation programs that train them in the procedure. Minimally invasive techniques like thoracoscopic-guided thoracentesis have also been developed.
Bibliography
“About Your PleurX™ Catheter.” Memorial Sloan Kettering Cancer Center, 12 July 2021, www.mskcc.org/cancer-care/patient-education/about-your-pleurx-drainage-catheter. Accessed 19 June 2024.
Colice, Gene L., et al. “Medical and Surgical Treatment of Parapneumonic Effusions: An Evidence-Based Guideline.” Chest, vol. 118.4, 2000, pp. 1158–71.
Ferrer, Jaume, et al. “Predictors of Pleural Malignancy in Patients with Pleural Effusion Undergoing Thoracoscopy.” Chest, vol. 127.3, 2005, pp. 1017–22.
Glargaard, Signe, et al. "Protocol: Thoracentesis to Alleviate Pleural Effusion in Acute Heart Failure: Study Protocol for the Multicentre, Open-label, Randomised Controlled TAP-IT Trial." BMJ Open, vol. 14, no. 1, 2024, doi.org/10.1136/bmjopen-2023-078155. Accessed 19 Jun 2024.
Light, Richard W. Pleural Diseases. 6th ed., Philadelphia: Lippincott, 2013.
Nicholson, Michael J., et al. "Thoracentesis for the Diagnosis and Management of Pleural Effusions: The Current State of a Centuries-Old Procedure." Journal of Respiration, vol. 3, no. 4, 2023, pp. 208-222, doi.org/10.3390/jor3040020. Accessed 19 Jun 2024.
Patel, Pankaj A., et al. "Ultrasonography Guidance Reduces Complications and Costs Associated with Thoracentesis Procedures." Journal of Clinical Ultrasound, vol. 40.3, 2012, pp. 135–41.
Puchalski, Jonathan T., et al. "The Safety of Thoracentesis in Patients with Uncorrected Bleeding Risk." Annals of the American Thoracic Society, vol. 10.4, 2013, pp. 336–41.
Zhao, Yuhua, et al. "Current Status of and Progress in the Treatment of Malignant Pleural Effusion of Lung Cancer." Frontiers in Oncology, vol. 12, 2022, doi.org/10.3389/fonc.2022.961440. Accessed 19 Jun 2024.