Pleural Effusion And Pneumothorax

Question 1

What is the most common cause of pleural effusion?

Answer 1

1) Cardiac failure
2) pneumonia
3) malignancy
4) pulmonary embolism due to ischaemia from the release of vasoactive cytokines that cause pleural effusion

Malignancy causes cancer cells to spread to the pleural space, increasing pleural fluid production

Question 2

Where is pleural fluid derived from?

Answer 2

Pleural fluid is typically derived from blood vessels of the parietal pleural surfaces. Fluid accumulation in the pleural space can compress the lungs and reduce the ability to expand. The parietal pleura contains sensory nerve fibres for pain perception.

Question 3

What is pleural effusion?

Answer 3

Accumulation of fluid in the pleural space that can compress the lungs and reduce their ability to expand

Question 4

What are the main causes of pleural fluid accumulation?

Answer 4

• Increased pulmonary capillary pressure
• Increased pulmonary capillary permeability assoicated with infection like pneumonia
• Obstruction of pleural lymphatic drainage
• Fluid migration from other sites
• Rupture of thoracic vessels, leading to haemothorax or chylothorax

Includes conditions like pneumonia and malignancies

Question 5

What does pleural fluid rich in lymphocytes indicate?

Answer 5

malignancy or tuberculosis.

Question 6

What is chylothorax?

Answer 6

Abnormal accumulation of chyle, a lipid-rich lymph, in the pleural space surrounding the lung. It causes pleural fluid to appear turbid, milky, serous or blood-stained and presence of high triglyceride level. It typically occurs with malignancy assoicated with lymphoma, trauma or following thoactomy.

This typically occurs due to congenital lymphatic abnormalities, malignancies of the lung, lymphoma or oesophageal and complication of tuberculosis.

Question 7

What are the symptoms of pleural effusion?

Answer 7

• Pleuritic chest pain, sharp severe localised pain worsened with breathing or coughing
• Fever
• Dyspnoea
• Cough
• Reduced tactile vocal fremitus
• Dullness to percussion
• Reduced vesicular sound

Question 8

What is a marker for lung injury?

Answer 8

LDH, WBCs, and protein

Question 9

What are the primary forms of pleural effusion based on fluid composition?

Answer 9

• Transudative effusion
• Exudative effusion

Question 10

What characterizes transudative effusion?

Answer 10

Results from conditions affecting hydrostatic/oncotic pressures, leading to fluid extravasation and composition is high in water.

Conditions where there is reduced production of albumin.

Question 11

Which conditions cause transexudative pleural effusion?

Answer 11

Pressure gradient disruption: right heart overload, left heart failure, pulmonary embolism

Low albumin: liver cirrhosis, nephrotic syndrome, peritoneal dialysis or atelectasis

Question 12

What characterizes exudative effusion?

Answer 12

Caused by increased capillary permeability, typically due to inflammation and high amounts of inflammatory cytokines

Question 13

What is the most common cause of exudative effusion in younger patients?

Answer 13

parapneumonic effusion

Question 14

What are the common causes of exudative effusion?

Answer 14

• Parapneumonic effusion
• Tuberculosis
• Pulmonary embolism
• Rheumatoid arthritis
• Malignancy
• Infection such as pneumonia or tuberculosis

Question 15

What are the less common causes of exudative effusion?

Answer 15

-> trauma from haemorrhoid
->Thoracic duct injury assoicated with chylothorax
->drugs such as methotrexate, amiodarone, phenytoin and dasatinib

Question 16

What is a parapneumonic effusion?

Answer 16

There is exudative effusion rich in protein which becomes complicated when bacteria infiltrate and WBCs and glucose increase progresses to Empyema: pus-filled pocket in the pleural space, characterised by high WBC count and fever and features of sepsis. It is assoicated with low pleural pH.

Question 17

What is empyema?

Answer 17

Pus-filled pocket in the pleural space characterized by high WBC count and fever

Question 18

What are the complications with pleural effusion?

Answer 18

Pleural fluid accumulating, creating pressure that makes a V/Q mismatch where ventilation is lowered and results in type 1 respiratory failure, especially with atelectasis
Parapneumonic effusion
Empyema: pus-filled pocket in the pleural space, characterised by high WBC count and fever and features of sepsis. It is assoicated with low pleural pH.

Question 19

What does Light’s criteria assess for?

Answer 19

Exudative effusion based on:
* Pleural protein ratio over 0.5
* Pleural LDH ratio over 0.6
* Pleural LDH greater than 2/

May not be accurate with heart failure for those on diuretics

Question 20

What indicates a complicated parapneumonic effusion or empyema?

Answer 20

Pleural pH less than 7.2, low pleural glucose levels, and low pleural WBC count

Question 21

What does milky pleural fluid typically indicate?

Answer 21

Chylothorax

Question 22

What are the investigations for pleural effusion?

Answer 22

FBC with U&Es, lLFTs, albumin, lipase enzyme, amylase and cardiac enzyme levels
Sputum culture, acid fast smear for mycobacterium tuberculosis
CXR
Echocardiogram to rule out heart failur -> if present, start on diuretics
Thoracentesis to assess the pleural fluid

Question 23

What does clear pleural effusion indicate?

Answer 23

clear fluid indicates absence of pleural protein and LDH, indicating transudative effusion, therefore from CHF, Liver cirrhosis or nephritic syndrome.

Question 24

What does cloudy fluid in pleural effusions indicate?

Answer 24

cloudy fluid indicates exudative effusion rich in proteins and LDH, indicating exudative effusion from lung injury.

Question 25

What do triglycerides in pleural fluid indicate?

Answer 25

chylothorax

Question 26

What does pleural amylase in pleural fluid indicate?

Answer 26

pancreatitis or oesophageal rupture

Question 27

What does low pleural glucose indicate?

Answer 27

empyema or parapneumonic effusion

Question 28

What does viscous pleural fluid indicate?

Answer 28

mesothelioma

Question 29

What does black pleural fluid indicate?

Answer 29

aspergillosis infection

Question 30

What is the test for autoimmune cause of pleural effusion?

Answer 30

ANA/Rheumatoid factor positive

Question 31

What is the test for tuberculosis in pleural fluid?

Answer 31

tuberculosis

Question 32

What is the treatment for heart failure-related pleural effusion?

Answer 32

No pleural tap unless atypical features present with presentwith bilateral effusion or they fail to resolve within 3 days following diuretics therapy.

Question 33

What is the treatment for parapneumonic effusion or empyema?

Answer 33

Chest tube drainage with needle aspiration and antibiotic treatment

Question 34

What is reccomended for recurrent malignant pleural effusion?

Answer 34

indwelling pleural catheter

Question 35

What is the treatment for refractory malignant effusion?

Answer 35

pleurodesis to reduce the pleural space

Question 36

What characterizes pneumothorax?

Answer 36

Pleuritic chest pain localized and worse on inspiration, dyspnoea, increased tactile fremitus, and decreased breath sounds

Question 37

How is pneumothorax classified?

Answer 37

Pneumothorax is classified by the British thoracic society based on the depth from the chest wall to the outer pulmoanry edge. A small pneumothorax is less than 2cm and a large pneumothorax is over 2cm. A patient is considered clinically stable in the absence of respiratory disturbance, thoracic CT is reccomended for identifying spontaneous pneumothorax.

Question 38

What is primary spontaneous pneumothorax associated with?

Answer 38

Tall, thin males aged 10-30 years, and conditions like Ehlers-Danlos syndrome or Marfan’s syndrome

Question 39

What is the pathophysiology of primary pneumothorax?

Answer 39

It is characterised by the formation of subpleural apical blebs, where pockets of air called bullae are found at the apex between the lung tissue and pleura that can rupture and allow air to enter the pleural space. For asymptomatic patients, observation is required for a small pneumothorax. This can be congenital where the upper pulmonary lobe develops faster than the vasuclature which causes a lack of blood supply. Alternatively tall individuals have more negative apical lung pressure and a over alveolar pressure that can led to bullae formation

Question 40

What is secondary spontaneous pneumothorax associated with?

Answer 40

Rupture of damaged pulmonary tissue, associated with Underlying lung conditions that predispose patinets to hyperinflation and the formation of bullae air pockets that can rupture and allow air to enter into the airspace -> more common in emphysema within COPD, severe asthma Lung necrosis due to infection or malignancy

Question 41

What is traumatic pneumothorax?

Answer 41

Traumatic pneumothorax typically occurs due to a needle aspiration from thoracentesis, lung biopsy, mechanical ventilation (due to positive pressure pneumothorax) or central lines, associated with cardiopulmonary function becoming unstable foll?owing the procedure.

Question 42

What are the complications with spontaneous pneumothorax?

Answer 42

Type 1 Respiratory failure due to V/Q mismatch-> more common in secondary pneumothorax and may result in a pulmonary shunt Increase in pressure due to air in the pleural space resulting in atelectasis Tension pneumothorax

Question 43

What is tension pneumothorax?

Answer 43

A condition where air enters the pleural cavity but cannot escape, increasing pleural pressure and therefore pleural cavity pressure increases and is compressing on structures on the mediastinum like the diaphragm and right side of the heart. It resuts in reducing diastolic filling, raised JVP, reduction in cardiac output and causes tracheal deviation away. There will be reduced breath sounds and cause the affected lung to collapse and contralteral lung and heart to be pressurised, leading to severe dyspnoea, cyanosis and hypotension

Question 44

What is the pressure gradient in the pleural pressure?

Answer 44

Pleural pressure is typically negative compared to atmospheric pressure during respiration and the pressure difference between pulmonary alveoli and pleural cavity is trans pulmonary pressure, which enables for lung elastic recoil. In pneumothorax, the air cavity is connected to the pleural cavity so air from the alvoeli migrates to the pleural cavity until the pressures of both are equal. There is a reduction in transpulmonary pressure and the vital capacity due to reduced ability of the lung to expand during inspiration. there is reduced arterial oxygen

Question 45

What is the recommended treatment for tension pneumothorax?

Answer 45

Immediate chest decompression

Question 46

How is pneumothorax diagnosed?

Answer 46

cxr shows absence of lung markings High resolution CT shows presence of bullae

Question 47

What is the treatment for primary pneumothorax?

Answer 47

Percutaneous simple needle aspiration for all patients requiring interveniton and progression to chest ctube when simple aspiration has failed

Question 48

What is the treatment of secondary pneumthorax?

Answer 48

Percutaneous simple needle aspiration for small pneumothorax even with mild pneumothorax and progression to chest tube except for patients with small pneumothorax and no respiratory symptoms

Question 49

How is a small pneumothorax treated?

Answer 49

Less than 2cm is with watchful waiting in hospital, serial CXR to assess for progression of pneumothorax andwh oxygen saturation

Question 50

How is a large pneumothorax treated?

Answer 50

Larger than 2cm and tension pneumothorax is treated with chest decmpression Ideally, needledecompression should be performed for tension pneumothorax, a life-saving emergency procedure where a needle is placed into the chest to decompress to alleviate symptoms and prevent further clinical deterioration. It should be avoided for simple pneumothorax

Question 51

What does a chest tube do?

Answer 51

Evacuates air or fluid from the pleural cavity and restores negative intra-thoracic pressure. There is a collection bottle from the patient via thoracentesis, water seal chamber where air bubbles indicate presence of pneumothorax or device abnormalities. There should be tidaling, where fluid moves up and down which is normal with breathing cycle. It is used to evacuate air from the pleural cavity and restore negative intrahtoracic pressure to promote lung expansion. It shold only be removed once CXR shows evidence of lung re-expansion.

Question 52

What is an indication for thoracic surgery?

Answer 52

Chest tube Air leaks beyond 2 days or failure of lung-expansion is an indication for thoracic surger y

Question 53

What does thoracic surgery include?

Answer 53

Thoracic surgery includes parietal pleurectomy , where parietal pleural is removed from the chest wall and pleurodesis, but is an alternative option when chest tube failure or needle aspiration has occurred. It is not reccomended for use in suction due to risk of pulmoanry oedema following re-expansion

Question 54

What is the significance of pleural fluid amylase levels?

Answer 54

Indicates pancreatitis or oesophageal rupture

Question 55

What is the typical management for traumatic pneumothorax?

Answer 55

Percutaneous simple needle aspiration or chest tube insertion depending on severity

Question 56

What is the effect of pneumothorax on transpulmonary pressure?

Answer 56

Reduces transpulmonary pressure leading to decreased vital capacity

Question 57

What does the presence of loculations in pleural fluid indicate?

Answer 57

Risk of empyema

Question 58

What is the initial diagnostic imaging for pneumothorax?

Answer 58

CXR (Chest X-Ray)

Question 59

What is the treatment for a small pneumothorax?

Answer 59

Watchful waiting and serial CXR

Question 60

What should be avoided in simple pneumothorax treatment?

Answer 60

Needle decompression