What is pleural disease?
The pleura is a pair of thin membranes: one covers the surface of the lung and the other lines the inside of the chest wall. Between them lies a potential space containing only a few millilitres of lubricating fluid, which allows the lung to slide smoothly as it expands and empties. Disease of the pleura means either that something has collected in this space or that the membranes themselves have become inflamed, thickened or invaded.
A collection of excess fluid is called a pleural effusion. When that fluid is infected and turns to pus, it is called an empyema. Blood in the space is a haemothorax and lymphatic fluid is a chylothorax. Air in the space is a pneumothorax, which allows the lung to collapse away from the chest wall. Because the pleural space is shared with the lung, anything that fills it compresses the lung and causes breathlessness.
Pleural disease is rarely a diagnosis in itself. It is a signpost to a cause elsewhere, which may be infection, heart, liver or kidney failure, tuberculosis, malignancy, pulmonary embolism or an autoimmune disease. The task is to relieve the patient's breathlessness and, in parallel, to identify the underlying cause precisely.
Symptoms of pleural disease
- Breathlessness, at first only on exertion and later at rest, in proportion to how much fluid or air has accumulated and how quickly.
- Pleuritic chest pain, a sharp catching pain on one side that is worse on deep breathing, coughing or lying on that side.
- Dry cough from compression and irritation of the lung.
- Fever, chills and sweats, suggesting infection such as parapneumonic effusion, empyema or tuberculosis.
- Weight loss and loss of appetite, raising concern about malignancy or tuberculosis.
- Sudden severe breathlessness with one-sided chest pain, typical of pneumothorax.
- Reduced chest movement on one side, with dullness on percussion and absent breath sounds on examination.
Sudden collapse with severe breathlessness, low blood pressure and distended neck veins may indicate a tension pneumothorax, which is a medical emergency requiring immediate decompression.
Common causes
| Type | Typical causes |
|---|---|
| Transudative effusion (low protein) | Heart failure, cirrhosis of the liver, nephrotic syndrome, severe hypoalbuminaemia, peritoneal dialysis |
| Exudative effusion (high protein) | Pneumonia, tuberculosis, malignancy, pulmonary embolism, rheumatoid arthritis and lupus, pancreatitis, post-cardiac injury |
| Empyema | Complicated bacterial pneumonia, lung abscess rupture, chest trauma, oesophageal perforation, post-surgical infection |
| Malignant effusion | Lung cancer, breast cancer, lymphoma, mesothelioma, ovarian and gastrointestinal cancers |
| Pneumothorax | Rupture of a small air sac in tall thin young adults, COPD and emphysema, trauma, past tuberculosis, procedures on the chest |
In India tuberculosis remains one of the leading causes of a unilateral lymphocytic exudative effusion in young adults, and malignancy becomes progressively more likely with age, smoking history and asbestos exposure.
How pleural disease is diagnosed
Imaging
A chest X-ray shows moderate and large collections. Thoracic ultrasound is more sensitive, detects small volumes, distinguishes fluid from thickening and collapse, identifies septations that predict a difficult drainage, and marks a safe puncture site at the bedside. Contrast-enhanced CT characterises pleural thickening, nodularity and underlying lung disease, and is important whenever malignancy or complex infection is suspected.
Diagnostic thoracentesis
Under ultrasound guidance and local anaesthesia, a small sample of fluid is aspirated with a needle. Analysis includes protein and LDH to classify the fluid as transudate or exudate using Light's criteria, glucose and pH in suspected infection, cell count and differential, Gram stain and culture, adenosine deaminase and GeneXpert for tuberculosis, cytology for malignant cells, and triglycerides where chylothorax is suspected.
Pleural biopsy and thoracoscopy
When fluid analysis does not give an answer, tissue is needed. Image-guided cutting-needle biopsy of thickened pleura has a good yield in tuberculosis and malignancy. Medical thoracoscopy, performed under local anaesthesia with sedation through a single small port, allows the operator to see the entire pleural surface, take multiple targeted biopsies, break down adhesions, drain the space completely, and perform talc pleurodesis in the same sitting. Its diagnostic yield in undiagnosed exudative effusions is very high.
Treatment
Relieving symptoms
Therapeutic aspiration removes fluid to relieve breathlessness quickly. Removal is limited in a single sitting to avoid re-expansion pulmonary oedema and chest discomfort. Where fluid recurs rapidly or infection is present, an intercostal drain is placed under ultrasound guidance and local anaesthesia and connected to an underwater seal.
Treating infection
Empyema and complicated parapneumonic effusion need prompt drainage in addition to a prolonged course of appropriate antibiotics. Intrapleural fibrinolytic therapy can break down septations and improve drainage in loculated collections. Surgical decortication is required when drainage fails or when a thick peel has already trapped the lung.
Treating tuberculous pleural effusion
Standard anti-tuberculosis therapy is the mainstay. Drainage is performed for symptomatic relief and to reduce residual pleural thickening, and follow-up ensures that the lung re-expands fully.
Managing malignant effusion
Treatment aims at durable relief of breathlessness alongside treatment of the underlying cancer. Options include chemical pleurodesis with talc, which seals the two pleural layers together, an indwelling tunnelled pleural catheter that the patient or family drains at home, or a combination of both. The choice depends on whether the lung re-expands after drainage, the patient's performance status and prognosis, and personal preference about hospital visits.
Pneumothorax
A small pneumothorax in a stable patient with no underlying lung disease may be observed with oxygen and repeat imaging. Larger or symptomatic collections are treated by needle aspiration or intercostal drainage. Persistent air leak, recurrence, or occurrence in a person whose occupation involves flying or diving is an indication for definitive treatment, usually thoracoscopic bullectomy with pleurodesis or pleural abrasion. Smoking cessation substantially reduces the risk of recurrence, and air travel is deferred until resolution has been confirmed radiologically.
Frequently asked questions
Is draining pleural fluid painful?
Local anaesthetic is infiltrated first, so the procedure is generally well tolerated. Patients feel pressure rather than sharp pain, and a cough as the lung re-expands is common. Ultrasound guidance improves both comfort and safety.
Will the fluid come back after it is drained?
That depends entirely on the cause. Fluid from heart failure or infection usually resolves once the cause is treated. Malignant effusions tend to recur, which is why pleurodesis or an indwelling catheter is offered rather than repeated needle drainage.
How much fluid can be removed at once?
Removal is usually limited in a single session, and the procedure is stopped earlier if chest tightness, persistent cough or discomfort develops. This avoids re-expansion pulmonary oedema, an uncommon but serious complication.
Does pleural effusion always mean cancer?
No. Heart failure, pneumonia and tuberculosis together account for the majority of effusions seen in India. However, an effusion without an obvious cause must be investigated properly rather than simply drained repeatedly.
What is medical thoracoscopy and how does it differ from surgery?
Medical thoracoscopy is performed by a pulmonologist through a single small port under local anaesthesia with sedation, with the patient breathing spontaneously. Surgical video-assisted thoracoscopy is performed by a thoracic surgeon under general anaesthesia with single-lung ventilation and allows more extensive procedures such as decortication and lung resection.
How long does a chest drain stay in place?
Usually a few days, until the lung has re-expanded, drainage has fallen to a low volume and any air leak has stopped. Empyema and complicated collections may need it for longer.
Can I fly after a pneumothorax?
Air travel should be postponed until radiological resolution is confirmed and the treating doctor advises that it is safe, typically some weeks after full expansion. Diving is generally avoided permanently after a spontaneous pneumothorax unless definitive surgical treatment has been performed.
Related conditions and procedures
Consult Dr. Gogineni Ratnakara Rao
Apollo Hospitals, Financial District: Monday to Saturday, 8:30 AM to 5:00 PM. Anything in Lung Clinic, Chanda Nagar: Monday to Saturday (Thursday closed), 6:00 PM to 9:00 PM.