iCliniq logo

Ask a Doctor Online Now

HomeHealth articlespneumothoraxWhat Is Thoracentesis?

Thoracentesis - Uses, Procedure, and Risk Factors

Verified dataVerified data

4 min read


Thoracentesis is the removal of air or fluid around the lungs. Read the article to learn about the uses and risk factors of thoracentesis.

Written by

Dr. Saberitha

Medically reviewed by

Dr. Kaushal Bhavsar

Published At September 20, 2022
Reviewed AtSeptember 20, 2022


Pneumothorax has air in the space around the lungs, while pleural effusion has fluid in the space around the lungs. The air and fluid are drained using the procedure called thoracentesis. It is also known as pleural tap. A needle is inserted through the chest to reach the space around the lungs. This space is called the pleural space.

What Are the Uses of Thoracentesis Procedure?

Thoracentesis is used to diagnose other systemic diseases. The various uses of thoracentesis are as follows:

  • Congestive Heart Failure - Pleural effusion impairs the respiratory mechanism and eventually causes congestive heart failure. This excess fluid can be removed using thoracentesis.

  • Microbial Infections - The microorganisms like bacteria, viruses, and fungi cause respiratory infections in the lungs. The type of infection can be diagnosed using thoracentesis.

  • Respiratory Diseases - In respiratory diseases like empyema, pneumonia, and tuberculosis, the pus or mucus is accumulated in the space around the lungs. The pus is collected using the thoracentesis procedure and sent to a lab for investigation by medical professionals.

  • Pulmonary Embolism - The obstruction of the airways by the blood clot causes embolism. This blood clot is diagnosed with thoracentesis.

  • Autoimmune Disorders - The patient with systemic lupus erythematosus (SLE) has fluid collected around the lungs. It results in pleural effusion. This condition is observed using thoracentesis.

  • Pancreatitis - The inflammation in the pancreatic tissue causes pancreatitis. The inflammatory chemicals secreted by the pancreas reach the lungs through the bloodstream. It causes inflammation in the air sacs with the fluid collection. This condition is called respiratory distress syndrome. The fluid is collected from the lungs using thoracentesis for examination.

  • Lung Cancer - The person affected by lung cancer has a weak immune system and is prone to infections. This infection results in blood clots or fluid collection in the lungs. It also affects other vital organs and causes cardiac failure or liver failure.

  • Mesothelioma - Asbestos is a chemical that causes potential damage to the tissues covering the lungs. This condition is called mesothelioma. It also causes pleural effusion. This underlying disease can be identified using thoracentesis.

What Are the Risk Factors for Thoracentesis?

The risk factors involved in thoracentesis are as follows:

  • Lung Collapse - Any injury to the lungs during the thoracentesis leaks air into the space, causing the lung to collapse.

  • Infection - Patients with bleeding disorders or patients taking blood-thinning medications have excess bleeding after the procedure. There is a chance of the infection spreading to the lungs.

  • Injury to Other Organs - If the needle is misplaced inside the organs like the spleen or liver, it results in injury. This condition is very rare.

  • Burns - Patients affected by burns or wounds need extra care during the insertion of the needle because the puncture of the needle may contaminate the wound or burn and cause severe skin infections.

How Is the Thoracentesis Procedure Performed?

  • The medical professionals perform the thoracentesis procedure in a hospital under conscious sedation.

  • It is performed either in a sitting position or lying over the bed, such that the doctor has access to the chest wall.

  • The procedure involves a localized area, so the area is cleaned with disinfectant and anesthetized.

  • With the guidance of a CT scan (computed tomography) or ultrasound scan, the needle is inserted into the chest space.

  • During the insertion of a needle or a flexible tube, the patient will feel uncomfortable pressure.

  • If the amount of fluid is more, the tube is attached for two to three days and allowed to drain inside the bag.

  • The patient has to be in a constant position without moving the body. The operator will drain the fluid accumulated in the lung space using the tube.

  • The doctor may ask the patient to hold the breathing during the needle insertion.

  • Once the fluid is drained, a small band-aid is placed over the needle-inserted area to avoid any contamination.

  • The collected fluid is sent to the lab for examination.

  • After the procedure, an X-ray is taken to observe the lungs and ribs.

  • The patient should be admitted to the hospital. The symptoms and vital signs are monitored at regular intervals after the procedure.

What Are the Instructions to Follow During Thoracentesis?

Before the procedure, it is better to inform the physician about preexisting systemic diseases. Few instructions are as follows:

  • Stop taking blood-thinning medications like Aspirin and Warfarin for three to four days before the procedure. Restart the medications after a physician's advice.

  • Any allergic reaction to medications or anesthesia must be reported to the doctor before the thoracentesis procedure.

  • Avoid thoracentesis procedures during pregnancy.

  • Patients with respiratory infections must take necessary precautions to avoid bleeding and empyema.

What Are the Diagnostic Procedures Used During Thoracentesis?

The location of the fluid accumulation and area of needle insertion is identified with the help of the diagnostic tools. They are as follows:

  • X-Rays - The X-rays are taken before and after the thoracentesis procedure. The presence of fluid can be revealed as gray shades in the image. The areas with air appear black in the X-rays. Using this color differentiation, the doctor observes the fluid or air present in the lung space.

  • Chest Fluoroscopy - It is used as an adjunct to X-rays. The movement and function of the respiratory tract and lungs are observed using chest fluoroscopy. The mass volume and elasticity of the lungs can be identified using fluoroscopy.

  • Ultrasound - The sound waves return to the transducer after assessing the required area. The echo created by the sound waves produces an image on the monitor. Any abnormality in the tissue or presence of fluid or air can be analyzed with the help of high-frequency sound waves.

  • CT-Scan (Computed Tomography) - The image provided by the scanner is used to observe the amount of fluid in the chest cavity, inflammation in the lungs, and the severity of the lung disease. It is also used to visualize the block in the airways. The images are useful to guide the surgeon during the insertion of a tube in the thoracentesis procedure.


The pressure in the space around the lungs is relieved using thoracentesis. The procedure takes about one to two hours. It does not require any stitches after the surgery. The radiologists interpret the results and follow up with the treatments. Once the fluid or air is removed, the lungs can expand and function normally.

Frequently Asked Questions


What Are the Steps in Thoracentesis?

Thoracentesis is a procedure for removing fluid or air around the lungs. An aseptic needle is inserted between the ribs in the back under anesthesia during the procedure. This needle enters the pleural space, and the fluid is drained by attaching a tube or a catheter to the other end of the needle. The fluid is sent for testing, and a chest X-ray is taken to ensure the lung condition.


What Is the Fluid Drained in Thoracentesis?

The fluid drained in thoracentesis is the pleural fluid found in the pleural space between the lung covering and the chest wall. There are only 20 milliliters of fluid in the pleural space typically. However, the patient may have shortness of breath and cough if it is in excess.


Is General Anesthesia Required During a Thoracentesis?

Thoracocentesis is carried out under local anesthesia and not general anesthesia. Local anesthetics are injected, and topical anesthetics are applied at the needle insertion site. And the use of local anesthetics is precautiously used in individuals taking blood-thinning medications.


Does Fluid Leak After Thoracentesis?

Fluid leakage may be possible even after 72 hours of thoracentesis. If there is no leakage, the bandage can be removed after 24 hours. But if there is a leakage, extra gauze is placed along with the dressing.


How Long Does It Take To Recover From Thoracentesis?

It generally takes around two to three days to recover after thoracentesis. However, the recovery time depends on the intensity of the individual's work. And if the patient has leakage even after 72 hours, rest for a few more days is recommended.


Is Cough Common During a Thoracentesis?

Yes, coughing after thoracentesis is common, and it lasts for about an hour, which helps the lung expand. But coughing during thoracentesis is also beneficial during therapeutic thoracentesis, as it prevents the excess pleural pressure drop. However, the exact mechanism is unknown.


What Happens After Thoracentesis?

Immediately after the procedure, the blood pressure, pulse, and breathing are monitored. The dressing placed over the needle insertion site is checked for blood or leakage. The individual should avoid strenuous exercise for a few days, but other daily activities can be resumed after the procedure.


How Long Does It Take for Thoracentesis?

The procedure of thoracentesis takes about 15 minutes to perform. However, the recovery time depends on the intensity of the individual's work.  The fluid drained during the process is sent to the laboratory, and results are obtained within a few hours.


How Many Times Can One Undergo Thoracentesis?

The number of times the procedure has to be repeated depends on the severity of the condition and the amount of fluid accumulation. On average, thoracentesis can be repeated every few days for two to three weeks.


How Much Amount of Fluid Can Be Drained During a Thoracentesis?

The maximum amount of fluid that can be drained during thoracentesis is one and a half liters. There are chances of re-expansion pulmonary edema if drained more than one and a half liters. However, some clinical benefits may be gained by removing more than one liter of fluid, and the traditional guidelines are always followed.


How to Prepare for Thoracentesis?

Preparation for thoracentesis starts with telling your doctor if you have any medical condition, are taking any medication, have a history of allergies, or are pregnant or breastfeeding. And stop taking the medicines instructed by the doctor. Before the procedure, a chest X-ray, chest fluoroscopy, ultrasound, or CT (computed tomography) scan may be taken to identify the location of the fluid.


What Are the Major Complications of Thoracentesis?

The significant complications of thoracentesis are:
 - Bleeding.
 - Infection.
 - Air in the pleural space causes the lung to collapse. 
 - Liver injury.
 - Spleen injury. 


Who Performs a Thoracentesis?

A pulmonologist and a radiologist perform thoracentesis. A radiologist usually performs the procedure by inserting a needle into the pleural cavity and drained out. A pulmonologist also performs the procedure to identify the cause of the pleural effusion.


When Is Thoracentesis Indicated?

Thoracentesis is indicated to diagnose health conditions such as:
 - Bacterial, viral, or fungal infections.
 - Cancer.
 - Congestive heart failure.
 - Pulmonary embolism.
 - Empyema.
 - Pancreatitis.
 - Systemic lupus erythematosus.
 - Tuberculosis.
 - Liver failure.
 - Pneumonia.


Where Is the Thoracentesis Needle Inserted?

The needle used in thoracentesis is inserted into the ribs in the back to enter the pleural space, which is the space between the chest wall and lung covering called the pleura. The other side of the needle is connected to the tubing for fluid drainage.
Source Article IclonSourcesSource Article Arrow
Dr. Kaushal Bhavsar
Dr. Kaushal Bhavsar

Pulmonology (Asthma Doctors)


Community Banner Mobile
By subscribing, I agree to iCliniq's Terms & Privacy Policy.

Source Article ArrowMost popular articles

Ask your health query to a doctor online

Pulmonology (Asthma Doctors)

*guaranteed answer within 4 hours

Disclaimer: No content published on this website is intended to be a substitute for professional medical diagnosis, advice or treatment by a trained physician. Seek advice from your physician or other qualified healthcare providers with questions you may have regarding your symptoms and medical condition for a complete medical diagnosis. Do not delay or disregard seeking professional medical advice because of something you have read on this website. Read our Editorial Process to know how we create content for health articles and queries.

This website uses cookies to ensure you get the best experience on our website. iCliniq privacy policy