Pleural Diseases: Overview and Practice Questions (2023)

Pleural diseases encompass a range of medical conditions that affect the pleura, the membrane lining the lungs and chest cavity.

These conditions can result from infection, inflammation, malignancy, or trauma, leading to symptoms such as chest pain, cough, and shortness of breath.

Accurate diagnosis and effective treatment are critical, given that pleural diseases can significantly impact respiratory function and quality of life.

This article provides a comprehensive overview of pleural diseases and includes helpful practice questions on this topic.

What are Pleural Diseases?

Pleural diseases are medical conditions affecting the pleura, the dual-layered membrane surrounding the lungs and lining the chest cavity. These diseases can result from various factors such as infection, inflammation, trauma, or malignancy. Symptoms often include chest pain, cough, and shortness of breath, requiring prompt diagnosis and treatment for effective management.

Types of Pleural Diseases

Pleural diseases encompass a variety of conditions affecting the pleura, which is the membrane lining the lungs and chest cavity. Here are some common types:

• Pleurisy: Inflammation of the pleura is often caused by infections, autoimmune diseases, or trauma. It leads to sharp chest pain, especially during breathing.
• Pleural Effusion: Accumulation of fluid in the pleural space, usually due to heart failure, infection, or malignancy. It can cause shortness of breath and chest discomfort.
• Pneumothorax: Presence of air or gas in the pleural space, leading to a collapsed lung. This can occur spontaneously or due to trauma or underlying lung disease.
• Hemothorax: Accumulation of blood in the pleural space, often resulting from trauma, surgery, or malignancy.
• Chylothorax: Accumulation of lymphatic fluid in the pleural space, usually due to trauma or malignancy affecting the thoracic duct.
• Mesothelioma: A rare form of cancer affecting the mesothelial cells of the pleura, often associated with asbestos exposure.
• Pleural Plaques: Localized areas of fibrous thickening of the pleura, usually benign and often due to prior asbestos exposure.
• Pleural Tumors: Other than mesothelioma, tumors can also originate from or metastasize to the pleura, affecting its function.
• Empyema: Infected pleural effusion, often a complication of pneumonia or surgery, requiring prompt drainage and antibiotic treatment.
• Pulmonary Edema: While primarily a lung condition, severe pulmonary edema can extend into the pleural space, exacerbating respiratory difficulties.

Note: Each of these conditions requires distinct diagnostic and therapeutic approaches for effective management.

Causes of Pleural Diseases

The causes of pleural diseases are diverse and can be grouped into several categories:

• Infections: Bacterial, viral, or fungal infections can lead to conditions like pleuritis or empyema. Pneumonia is a common infectious cause of pleural effusion.
• Inflammation: Autoimmune diseases like lupus or rheumatoid arthritis can cause pleuritis and pleural effusion.
• Trauma: Physical injury to the chest can result in pneumothorax or hemothorax.
• Malignancy: Lung cancer, mesothelioma, and metastatic cancers from other organs can cause malignant pleural effusions and other pleural abnormalities.
• Cardiovascular Issues: Congestive heart failure often results in pleural effusion due to fluid back-up.
• Lung Diseases: Conditions like chronic obstructive pulmonary disease (COPD) or tuberculosis can cause pleural problems.
• Gastrointestinal Conditions: Liver cirrhosis and pancreatitis can sometimes result in pleural effusion due to inflammation and fluid imbalances.
• Surgical and Medical Procedures: Procedures like thoracentesis or mechanical ventilation can cause iatrogenic pneumothorax.
• Environmental Exposures: Asbestos exposure is strongly linked to pleural plaques and mesothelioma.
• Other: Chylothorax can occur due to lymphatic system dysfunction. Pulmonary embolism and kidney diseases like nephrotic syndrome can also cause pleural effusion.
• Idiopathic: In some cases, the cause may be unknown, as in some instances of spontaneous pneumothorax.

Note: Understanding the underlying causes is crucial for appropriate diagnosis and management of pleural diseases.

What are the Most Common Pleural Diseases?

The two primary types of pleural diseases include:

1. Pleural effusion
2. Pneumothorax

Pleural Effusion

This condition occurs when there is an abnormal accumulation of fluid in the pleural space between the visceral and parietal pleura. Pleural effusions can be caused by a variety of underlying conditions such as heart failure, infection, malignancy, or inflammation.

Depending on the composition of the fluid, effusions are classified as either transudative or exudative.

Symptoms may include shortness of breath, cough, and chest pain, and treatment often involves draining the fluid and addressing the underlying cause.

Pneumothorax

This refers to the presence of air or gas in the pleural space, causing the lung to collapse partially or completely. Pneumothorax can be spontaneous, traumatic, or iatrogenic (caused by medical intervention).

The presence of air disrupts the negative pressure in the pleural space, impairing the lung’s ability to expand during inhalation.

Symptoms include sudden, sharp chest pain and shortness of breath. Treatment typically involves the removal of air, usually through a chest tube, and addressing the underlying condition if present.

Note: These two primary types of pleural diseases can present with overlapping symptoms but generally require different approaches to diagnosis and treatment. Early and accurate identification is crucial for effective management and optimal patient outcomes.

What is the Pleural Space?

The pleural space is the thin, fluid-filled cavity between the two layers of the pleura, which are membranes that line the chest cavity and envelop the lungs.

This space serves as a lubricating cushion, allowing the two pleural layers to slide against each other seamlessly during breathing.

The pleural fluid within this space facilitates smooth lung expansion and contraction, making it essential for normal respiratory function.

Abnormalities in the pleural space, such as fluid accumulation or air leakage, can lead to pleural diseases that impair breathing.

Types of Pleura

The pleura is composed of two main types:

1. Visceral Pleura: This inner layer of the pleura directly covers the lungs and extends into the lung fissures. It is tightly adhered to the lung tissue, moving along with the lungs during inhalation and exhalation.
2. Parietal Pleura: This is the outer layer that lines the inner surface of the chest wall, diaphragm, and the mediastinum. It is attached to these structures and does not move with the lungs.

Both layers are composed of mesothelial cells and are separated by the pleural space, which contains a small amount of lubricating fluid that allows the two layers to slide against each other easily, facilitating lung movement during breathing.

Abnormalities or diseases affecting these layers can lead to various respiratory issues.

Pleural Disease Practice Questions

1. What are the two most common pleural diseases that you should know about as a respiratory therapist?
Pleural effusion and pneumothorax

2. When do pleural effusions form?
When excess pleural fluid is produced by the lung or chest wall in sufficient quantities to overcome the resorptive capacity of the pleural lymphatic vessels

3. Pleural fluid analysis is the key to what?
It is the key to understanding the specific cause of any pleural effusion.

4. Transudates have a pleural fluid total protein level of what?
Less than 0.5 and an LDH level of less than 0.6 of the respective serum values

5. What are the common causes of a transudative effusion?
The common causes include CHF, nephrosis, and cirrhosis.

6. Pleural fluid drainage returns approximately one-third of the lung volume as measured by what?
FVC; the other two-thirds of fluid drainage allows the diaphragm to rise and the chest wall to normalize.

7. Is a pneumothorax size underestimated or overestimated with a one-dimensional view of the chest?
It is underestimated. Measurement accuracy requires a three-dimensional perspective.

8. Are the risk factors for a pneumothorax and pneumomediastinum the same?
Yes, air ruptures a pleural membrane in a pneumothorax, and air passes through the lung hilum in a pneumomediastinum.

9. Pleural effusions associated with CHF are usually bilateral or unilateral?
Bilateral

10. What does chest tube flow depend on?
It depends on tube size, stopcock size, and collection system resistance.

11. Breath-by-breath measurement of an air leak can be approximated by what?
By the difference between inspired and expired volumes (in the absence of endotracheal cuff leaks)

12. The mode of ventilation that produces the least fistula airflow is the most likely to produce what?
Healing

13. What are the methods to decrease bronchopleural fistula airflow?
Lowering the tidal volume, respiratory rate, PEEP, and avoiding auto-PEEP. In more severe cases, positioning the affected lung down, double-lumen tube ventilation, adding PEEP valves to the chest tube, inspiratory chest tube occlusion, or thoracic surgery should be considered

14. What is a bronchopleural fistula?
Any air communication from the lungs to pleural space

15. What is an empyema?
A collection of pus in the pleural space

16. What is an exudative pleural effusion?
Any pleural effusion high in protein or lactate dehydrogenase, which implies inflammation or vascular injury on the pleural surface

17. What is a hemothorax?
Presence of blood within the pleural space

18. What is the parietal pleura?
A membrane covering the surface of the chest wall, mediastinum, and diaphragm that is continuous with the visceral pleura around the lung hilum.

19. What is a pleural effusion?
Abnormal collection of fluid within the pleural space

20. What is used to remove fluid from a pleural effusion?
Chest tube and thoracentesis

21. What is a primary spontaneous pneumothorax?
A pneumothorax that occurs without underlying lung disease

22. What is re-expansion pulmonary edema?
Pulmonary edema that forms after rapid re-expansion of a lung that has been compressed with pleural fluid or pneumothorax

23. What is a secondary spontaneous pneumothorax?
A pneumothorax that occurs because of underlying lung disease

24. What is a stomata?
Small holes within the parietal pleura that are the main route for pleural fluid to exit

25. What is a thoracentesis?
Surgical perforation of the chest wall and pleural space with a needle for diagnostic or therapeutic purposes or for removal of a specimen for biopsy

26. What is a transudative pleural effusion?
Pleural effusion low in protein or lactate dehydrogenase, usually caused by congestive heart failure, nephrosis, or cirrhosis

27. What is ascites?
The accumulation of fluid in the abdomen

28. What is atelectasis?
When segments of the lung collapse, intrapleural pressure becomes more negative and can produce small effusions

29. What is the primary cause of a transudative pleural effusion?
CHF

30. How is chest radiography used for pleural diseases?
It is most common in detecting a pleural effusion obtained best in the upright position to show a pleural fluid meniscus at the costophrenic angles.

31. How is CHF relevant to pleural diseases?
It is the most common cause of a clinical pleural effusion. It stems from the elevation of pressure in the left atrium and pulmonary veins.

32. How is computed tomography relevant to pleural diseases?
CT scanning of the chest is the most sensitive study for the identification of a pleural effusion.

33. Which side are pleural effusions more common on?
Right

34. Can a pleural effusion cause atelectasis?
Yes, because the fluid limits the ability of the thorax to expand.

35. What unit are chest tubes measured in?
French (Fr)

36. Where is the needle for a thoracentesis inserted?
Just above the rib

37. What is lateral decubitus chest radiography used for?
It can help define the presence or absence of pleural effusion.

38. How many bottles are in a standard chest tube drainage system?
3

39. What does it mean if tidaling does not occur in the water seal chamber?
It means that there could be a kink, clamp, or occlusion in the tubing.

40. What are the common causes of penetrating chest trauma?
Gunshot wounds and knife punctures

41. What is pleurisy?
A respiratory condition characterized by pain and inflammation in the pleura that usually results from a viral infection

42. What is pleurodesis?
A procedure that is performed to obliterate the pleural space

43. How would you describe chest pain from a pneumothorax?
Sharp and abrupt

44. What are the findings of a tension pneumothorax?
Mediastinal shift, decreased venous return, decreased cardiac output, hypotension, tachycardia, and hypoxemia

45. What is the treatment for a tension pneumothorax?
Emergency decompression of the chest

46. Chest palpitation during pleural diseases would reveal what?
Dull percussion note

47. What is the most common type of traumatic pneumothorax?
Iatrogenic pneumothorax

48. What are the risk factors of a Thoracentesis?
Intercostal artery laceration, infection, and pneumothorax

49. Which pleura surrounds the surface of the lungs and interlobar fissures?
Visceral pleura

50. Which pleura covers the entire surface of the diaphragm and thoracic cavity?
Parietal pleura

51. What is the pleural cuff?
The pleural cuff refers to the region where the visceral pleura transitions to the parietal pleura at the lung hilum.

52. What is an abnormal accumulation of fluid in the intrapleural space?
An abnormal accumulation of fluid in the intrapleural space is known as pleural effusion.

53. Which condition would be the result of air in the pleural space?
The presence of air in the pleural space results in a pneumothorax.

54. Where does tidaling occur in a chest tube?
Tidaling occurs in the water seal chamber of a chest tube, where the fluid level rises and falls with breathing.

55. What is pyothoracosis?
Pyothoracosis is a rare condition characterized by a chronic, encapsulated pleural infection, often requiring surgical intervention.

FAQs About Pleural Diseases

What are the Symptoms of Pleural Diseases?

Symptoms of pleural diseases can vary depending on the specific condition, but commonly observed symptoms include:

• Chest pain, often worsened by coughing or breathing
• Shortness of breath or difficulty breathing
• Cough, sometimes with the production of phlegm or blood
• Fatigue or general malaise
• Fever and chills, particularly in cases of infection

Some conditions may produce unique symptoms; for example, pneumothorax might cause a sudden, sharp pain and severe difficulty in breathing.

How Do You Diagnose Pleural Diseases?

Diagnosis of pleural diseases involves a combination of clinical assessment, imaging studies, and laboratory tests. Key diagnostic steps often include:

• Medical history and physical examination: Assessing symptoms, risk factors, and performing a thorough chest examination.
• Chest X-ray: Provides initial information about pleural effusion, pneumothorax, or other abnormalities.
• CT scans or MRI: Offers detailed imaging that can identify tumors, thickening, or small effusions not visible on an X-ray.
• Ultrasound: Used primarily for guiding procedures like thoracentesis but can also help diagnose pleural effusions.
• Blood Tests: Can help in diagnosing infections or other systemic conditions affecting the pleura.
• Thoracentesis: Removal of a small amount of pleural fluid for analysis to determine the cause of an effusion.
• Pleural biopsy: May be performed to diagnose conditions like mesothelioma or tuberculosis.

How Do You Treat a Pleural Disease?

Treatment for pleural diseases varies depending on the underlying cause, symptoms, and overall patient health.

Some common treatment methods include:

• Antibiotics or antifungal medications for infections
• Anti-inflammatory drugs for pleuritis
• Thoracentesis or chest tube placement for draining pleural effusions
• Surgery for conditions like pneumothorax, hemothorax, or tumors
• Chemotherapy or radiation for malignancies like mesothelioma
• Oxygen therapy for patients experiencing significant shortness of breath

Management often requires a multidisciplinary approach involving pulmonologists, surgeons, oncologists, and other specialists for comprehensive care.

What are the Chest Signs of a Pleural Disease?

Chest signs in pleural diseases can vary, but clinicians often look for the following during physical examination:

• Reduced Chest Expansion: One side of the chest may not expand as well as the other during inhalation.
• Dullness to Percussion: A dull sound when tapping the chest can indicate fluid accumulation, as in pleural effusion.
• Decreased or Absent Breath Sounds: Listening with a stethoscope may reveal decreased or absent breath sounds over areas affected by effusion or pneumothorax.
• Pleural Rub: A grating sound heard during auscultation may indicate pleuritis.
• Hyperresonance: An unusually low-pitched sound when tapping the chest can indicate the presence of air, as in pneumothorax.

Are Pleural Disorders Life-Threatening?

The severity of pleural disorders can range from mild to life-threatening, depending on the underlying cause, extent of disease, and overall health of the patient. For instance:

• Pleuritis caused by a viral infection might resolve on its own or with basic treatment and is generally not life-threatening.
• Pleural effusions due to heart failure may indicate a more severe underlying condition requiring urgent treatment.
• A tension pneumothorax can rapidly lead to respiratory failure and is a medical emergency requiring immediate intervention.
• Malignant pleural diseases like mesothelioma often have a poor prognosis and can be life-threatening.

Early diagnosis and appropriate treatment are crucial for managing the risks associated with pleural diseases effectively.

Final Thoughts

Understanding pleural diseases is essential for accurate diagnosis and effective management.

With a variety of underlying causes—ranging from bacterial infections to cancer—the symptoms can often be non-specific, making early detection challenging.

Advances in diagnostic tools, including imaging and biopsy techniques, have enhanced our ability to diagnose these conditions accurately.

Current therapeutic strategies, such as antibiotics for infections and surgical interventions for malignancies, continue to evolve, improving outcomes and quality of life for patients.