Breathlessness Associated With Pleural Effusion

Introduction

Breathlessness is a life-threatening symptom caused by many conditions. Pleural effusion is one of the common causes of breathlessness. It has a significant impact on the respiratory system. It causes abnormalities in gas exchange, mechanism of respiration, respiratory muscles, and hemodynamics. In addition, pleural effusion pushes on the chest wall and respiratory muscle. This makes breathing difficult.

What Is Pleural Effusion?

The lungs are covered with layers called parietal pleura and visceral pleura. The space between these two layers is called the pleural cavity. Pleural effusion is the accumulation of fluid in the pleural cavity. Some fluid is normally present in the pleural space to allow the lungs to move smoothly during breaths. Pleural fluid is produced by parietal pleural capillaries and absorbed by lymphatic drainage. Excess fluid increases resistance against lung expansion and results in collapsed lungs. Different kinds of fluid can accumulate in the pleural cavity, such as serous fluid (hydrothorax), chyle (chylothorax), blood (hemothorax), pus (pyothorax), and urine (urinothorax). Pleural effusion commonly refers to hydrothorax. It can also occur with pneumothorax (accumulation of air in the pleural cavity), leading to hydropneumothorax.

What Are the Causes of Pleural Effusion?

Pleural effusion can be caused by transudative or exudative fluid. Increased pressure on small and large blood vessels of organs produces protein-filled fluid. This fluid collection occurs with coronary heart disease or cirrhosis. Exudate is produced during irritation, inflammation, or infection. This leads to increased fluid production and reduced drainage.

Transudative pleural effusion occurs in:

• Congestive heart failure.

• Liver cirrhosis.

• Kidney diseases.

• Peritoneal dialysis.

• Malnutrition due to low albumin in the blood.

Exudative pleural effusion occurs in:

• Inflammation.

• Infection.

• Tumors.

• Lung injury.

Other conditions that cause this type of effusion are:

• Tuberculosis.

• Cancer.

• Pancreatitis, lupus, or rheumatoid arthritis.

• Chylothorax.

• Pneumonia.

• Hemothorax.

• Pulmonary embolism results in transudative or exudative pleural effusion.

What Are the Symptoms of Pleural Effusion?

The heaviness of the chest is an important symptom of pleural effusion. Pleuritis will be painful, but when effusion starts to develop, it will subside.

Symptoms include:

• The heaviness of the chest.

• Chest pain.

• Dry, nonproductive cough.

• Dyspnea (breathlessness).

• Orthopnea (difficulty in breathing on lying).

How Does Pleural Effusion Cause Breathlessness?

Pleural effusion causes expansion of the chest cavity and reduction in the lung volume. Expansion occurs in the vertical dimension and distorts the hemidiaphragm leading to downward displacement of the dome of the diaphragm (respiratory muscle). This reduces muscle length and causes flattening or inversion of the diaphragm. This leads to breathlessness.

What Are the Complications of Breathlessness?

Breathlessness results in low blood oxygen levels (hypoxia or hypoxemia). This leads to a decrease in consciousness and other symptoms. If this persists for a long time, it can cause temporary or permanent cognitive impairment.

What Are the Complications of Pleural Effusion?

Complications of pleural effusion include:

• Temporary or permanent lung damage.

• Empyema - formation of an abscess.

• Air forms in the chest cavity after draining the pleural fluid (pneumothorax).

• Thickening of pleural membrane and scar formation.

How Is Pleural Effusion Diagnosed?

Following tests are done to confirm pleural effusion;

• Ultrasound - Ultrasound of the chest plays a very important role in the diagnosis of effusion, in identifying loculations, and also helps in ultrasound-guided thoracocentesis.

• Chest X-ray - Chest X-ray is used to examine the presence of pleural fluid. Pleural fluid appears white, and air space appears black on the x-ray.

• Computed Tomography (CT Scan) - CT scan helps examine lung lesions, masses, and enlarged lymph nodes. In a CT, the thickening of pleura and fluid accumulation can be seen. It also helps to select the drainage site, differentiate between empyema and lung abscess, and locate the chest tube in a failed drainage.

• Thoracocentesis and Cyto Biochemical Analysis - Pleural effusion is aspirated, and biochemical, cytological, and microbiological examination is done for diagnosis. Routine evaluation includes protein, pH, lactate dehydrogenase, glucose, and albumin levels, with adenosine deaminase evaluation for differential and cytological examination.

• Percutaneous Pleural Biopsy - It is used to diagnose granulomatous and malignant diseases of the pleura. It is performed as a blind percutaneous needle biopsy or through thoracoscopy or thoracotomy. It is done if there is clinical suspicion of tuberculosis or malignancy in patients with undiagnosed exudative effusions and non-diagnostic cytology.

• Thoracoscopy - It is a less invasive video-assisted procedure. It is done when invasive tests have not given a diagnosis. It is also used in chemical pleurodesis for malignant pleural effusion, repair of a bronchopleural fistula, and drainage and lysis of loculations in pleural effusion.

How Is Pleural Effusion Treated?

Treatment of the underlying cause is the key to managing pleural effusion.

• Drugs - Fibrinolytics like streptokinase and Urokinase can be used to treat loculated effusion.

• Thoracentesis - A local anesthetic agent is injected between the ribs, and a needle is inserted through the chest wall between the ribs to remove the fluid. Pleural fluid is drained to relieve symptoms and is used for testing.

• Tube Thoracostomy (Chest Tube) - A small cut in the chest wall is created, and a plastic tube is placed into the pleural space.

• Pleural Drain - If the pleural effusion is recurrent, a long-term catheter is placed in the pleural space to drain the fluid at home.

• Pleurodesis - A talc or Doxycycline is injected into the pleural space through the chest tube. This inflames the pleura and the chest wall and binds tightly to each other as they heal. It prevents pleural effusion from recurring.

• Surgery - Surgery is done if pleural effusions cannot be managed through drainage or pleural sclerosis. Pleural decortication, pleurectomy, pleuropneumonectomy, closure of bronchopleural fistula with or without grafts, window operation, fenestration surgery, thoracostomy, and thoracoplasty are the surgical techniques available to treat pleural effusion. Surgery is done for malignant involvement, empyema with or without bronchopleural fistula, and fibrothorax.

• Drugs - Diuretics treat pleural effusion caused by congestive heart failure. The chest treats pleural effusion associated with malignancy with chemotherapy, radiation therapy, or medicine infusion. Antibiotics are given to treat bacterial infections. Steroids and anti-inflammatory medicines are given to treat pain and inflammation.

Conclusion

Pleural effusion is a life-threatening condition. A positive outcome is seen with treatment. It is important to seek medical advice on experiencing shortness of breath. Appropriate treatment prevents complications. Complications like empyema, sepsis, or collapsed lungs can occur without treatment. Recovery time depends on the cause, severity of pleural effusion, and overall health of the individual. The range of treatment options for pleural effusions is wider. Development of interventional techniques, pleurodesis agents, diagnostic tests, and the genetic background of the patients are effective therapeutic options.