Pleural Fluid Analysis - Usage, Procedure, Risk, and Results

Introduction:

The pleural fluid is a liquid situated between two layers of a membrane called the pleura, which covers the lungs and lines the chest cavity. It maintains the moisture of the pleura and reduces friction between the layers while breathing. The pleural space is the region that contains the pleural fluid, and a small amount of it usually exists in this space. In some cases, excess fluid accumulates in the pleural space, causing pleural effusion, which hinders full lung expansion, leading to breathing difficulties. A pleural fluid analysis comprises a set of examinations that aid in identifying the underlying cause of the pleural effusion.

What Causes Pleural Effusion?

Various factors, including congestive heart failure, pneumonia, cancer, autoimmune diseases, kidney disease, liver cirrhosis, tuberculosis, pulmonary embolism, and trauma, can cause pleural effusion. The accumulation of excessive amounts of fluid in the pleural cavity may occur due to increased pressure within blood vessels or inflammation of the pleura, which is the thin membrane lining the lungs and chest wall. The underlying cause of pleural effusion must be determined to guide appropriate treatment.

What Is the Usage?

A pleural fluid analysis is utilized to diagnose the underlying cause of the pleural effusion. There are two primary types of pleural effusion:

• The first type is transudate, which results from a disturbance in the pressure equilibrium of specific blood vessels, causing excess fluid to leak into the pleural space. This is commonly caused by heart failure or cirrhosis.

• The second type is an exudate, which occurs when there is an injury or inflammation to the pleura, resulting in excess fluid leaking out of specific blood vessels. This type of pleural effusion has various causes, including infections such as pneumonia, cancer, kidney disease, and autoimmune diseases, and typically affects one side of the chest.

How Does Pleural Fluid Analysis Help?

Symptoms of pleural effusion include:

• Chest pain.

• Dry, nonproductive cough.

• Trouble breathing.

• Fatigue.

Some people may not have initial symptoms of pleural effusion. A doctor can prescribe this test if a chest X-ray for another reason indicates pleural effusion.

How to Perform the Pleural Fluid Analysis?

To perform a pleural fluid analysis, the healthcare provider will remove pleural fluid from the pleural space through a procedure called thoracentesis. The procedure may take place in a hospital or doctor's office and involves the following steps:

• The patient will be asked to undress and wear a gown to be adequately covered.

• The patient is asked to sit on a hospital bed or chair with his arms resting on a padded table to assume the correct position.

• The healthcare provider will clean a spot on the back with an antiseptic solution.

• The healthcare provider will numb the area with a numbing medicine so that there is no pain during the procedure.

• After the area is numb, the healthcare provider will insert a needle between the ribs into the pleural space, possibly using ultrasound imaging to find the optimal insertion site.

• The patient may feel some pressure when the needle is inserted.

• The healthcare provider will withdraw fluid into the needle, and the patient may be asked to hold their breath or breathe out deeply at specific points during the procedure.

• Once an adequate amount of fluid has been extracted, the needle will be taken out, and the puncture site will be bandaged.

• A blood test may be necessary to calculate Light's criteria because certain protein levels in the blood must be analyzed.

What Measures Should a Patient Take Before the Test?

A person may need to take certain precautions before the pleural fluid analysis procedure. The healthcare provider will provide the patient with specific instructions, which may include the following:

• Informing the healthcare provider of any medications or supplements, as some may need to be temporarily discontinued before the procedure.

• Not eating or drinking for several hours before the test.

• Emptying the bladder before the test.

• Bringing a list of any allergies or medical conditions.

• Arranging for someone to drive a person home after the procedure, as they may feel weak or dizzy.

What Is the Risk Associated With It?

Like any medical procedure, pleural fluid analysis carries some risks. However, serious complications are rare. The risks may include the following:

• Pain or discomfort during the procedure.

• Bleeding at the needle insertion site.

• Infection in the pleural space.

• Collapsed lung (pneumothorax) if the needle accidentally punctured the lung.

• Low blood pressure or fainting due to the removal of a large amount of fluid.

It is essential to discuss any concerns or questions about the advantages and risks of the procedure with the healthcare provider before the test. After the procedure, the healthcare provider may recommend a chest X-ray to ensure there are no complications.

What Do the Test Results Mean?

• Normal Results: Typically, the pleural space contains a small amount of serous fluid that is clear and yellowish, usually less than 20 milliliters (equivalent to four teaspoons).

• Abnormal Results: The test may reveal abnormal results that suggest potential reasons for pleural effusion, such as cancer, heart failure, cirrhosis, infections, severe malnutrition, trauma, or abnormal connections between the pleural space and other organs. The fluid may be cultured to detect bacteria and other microorganisms if an infection is suspected. Additionally, the test may be conducted to diagnose hemothorax, which is the accumulation of blood in the pleural cavity.

The results of the pleural fluid analysis may be compared to other tests, such as glucose and albumin tests, to determine the type of pleural effusion present using Light's criteria. Albumin is a protein produced by the liver.

Conclusion:

In conclusion, pleural effusion occurs when excess fluid accumulates in the pleural space, causing breathing difficulties. A pleural fluid analysis is used to identify the underlying cause of pleural effusion, possibly due to a range of factors such as infections, cancer, autoimmune diseases, or trauma. There are two primary types of pleural effusions: transudate and exudate. The healthcare provider may use Light's criteria to determine the type of pleural effusion. Thoracentesis is used to collect the pleural fluid for analysis. Before the test, a patient may need to take certain precautions, and there are some risks associated with the procedure. Abnormal results can indicate potential reasons for pleural effusion, such as infections, cancer, heart failure, cirrhosis, or trauma.