S10: pneumothorax & pleural effusion

Question 1

What is the pleural cavity?

Answer 1

A potential space that is made up by the parietal and visceral pleura

Question 2

Define a pneumothorax

Answer 2

Air within the pleural cavity
Disruption of the pleura -> air flows from higher pressure to lower pressure -> disruption of the balance -> lung collapses

Question 3

Define simple pneumothorax

Answer 3

Air enters the pleural space through a pleural opening because of pressure differential
BUT air can egress out of the opening

Question 4

List the presenting symptoms of a simple pneumothorax

Answer 4

Chest pain: pleuritic, sudden onset & sharp pain
+/- SOB
History of trauma/lung disease

Question 5

List the clinical signs of a simple pneumothorax

Answer 5

Normal trachea position
Chest movement reduced on affected side
Hyper-resonant/resonant on affected side during percussion
Auscultation: reduced/absent breath sounds
Vocal/tactile resonance: reduced on affected side

Question 6

Describe the radiological features seen in a simple pneumothorax

Answer 6

CXR: hyper-lucent, absent lung markings & collapsed lung borders seen
CT-chest: absent lung markings, collapsed lung borders seen

Question 7

List treatment options for a simple pneumothorax

Answer 7

Conservative treatment
Pleural aspiration
Chest drain - 4th intercoastal space in mid-axillary line, just above 5th rib

Question 8

Describe chest drains

Answer 8

Ultrasound-guided and inserted into the safe triangle
Other side = underwater seal
-during inspiration: when the patient breathes in, the water seal prevents entrainment of room air
-during expiration: air leaves the pleural cavity -> water is pushed back into the bag
-constantly removing the air from the pleural cavity & not allowing anymore to enter

Question 9

Define tension pneumothorax

Answer 9

Air enters and accumulates in the pleural space
BUT air cannot egress out of the opening – opening in pleura covered by a flap of tissue = acts as one way valve
Air continues to enter intrapleural space and pressure increases

Question 10

Explain the pathophysiology of a tension pneumothorax

Answer 10

Affected lung collapses -> affects gas exchange/ventilation-hypoxia
Increased pressure causing mediastinum to shift & push on other lung
Increased pressure decreases venous return to right atrium (pressure on SVC & kinking of IVC)
Cardiac function impaired
Progresses to respiratory insufficiency, CVS collapse & death if unrecognised and untreated

Question 11

List the presenting symptoms of tension pneumothorax

Answer 11

Chest pain: pleuritic, sudden onset, sharp pain
\+/- SOB 
History of trauma/lung disease 
Respiratory distress
Cyanosis
Tachycardia & hypoxaemia

Question 12

List the clinical signs of a tension pneumothorax

Answer 12

Trachea deviated away from the affected side
Chest movement reduced on affected side
Reduced/absent breath sounds on affected side during auscultation
Hypotension
Cardiac apical displacement

Question 13

Describe the radiological findings for a tension pneumothorax

Answer 13

Absent lung markings on affected side
Hyperlucency on affected side
Lung edge visible – affected side
Ribs more horizontal & over-expanded on affected side
Marked mediastinal and tracheal shift away from affected lung

Question 14

Describe the treatment for a tension pneumothorax

Answer 14

Immediate needle decompression by inserting a large bore (14-or16-gauge) needle into the 2nd intercoastal space mid-clavicular line
Make sure it is the correct side!

Question 15

Differentiate between primary and secondary pneumothorax

Answer 15

Primary – no underlying lung pathology
Risk factors: male, young, fhx of pneumothorax & smoking
Secondary – underlying lung pathology eg. COPD, asthma, bronchiectasis, lung cancer etc

Question 16

Differentiate between spontaneous, iatrogenic and traumatic pneumothorax

Answer 16

Spontaneous – due to rupture of sub pleural bleb or bulla
Iatrogenic – insertion of central lines/pacing
Trauma – severe chest wall injury eg. stab wound or gunshot wound -> allows air to enter the pleural space & rib fractures -> puncture the visceral pleura

Question 17

What is a pleural effusion?

Answer 17

Excess fluid in the pleural cavity

Imbalance between rate of production and absorption

Question 18

Define simple effusion, haemothorax, chylothorax & empyema

Answer 18

Simple effusion: when the fluid is pleural fluid – can be transudate or exudate
Haemothorax: when the fluid is blood (eg. trauma)
Chylothorax: when the fluid is lymph (eg. leak from lymphatic duct)
Empyema: when fluid is pus

Question 19

Describe the presenting symptoms for a pleural effusion

Answer 19

Gradual onset SOB
Pleuritic chest pain
+/- features of underlying clinical disease: congestive cardiac failure, lung malignancy

Question 20

Describe clinical signs for a pleural effusion

Answer 20

Trachea deviated from the affected side
Reduced chest movement on affected side
‘stony’ dull on affected side (percussion note)
Breath sounds: reduced/absent on affected side
Vocal resonance is reduced on affected side

Question 21

Describe investigations for a pleural effusion

Answer 21

Radiological findings – fluid meniscus (can’t differentiate what type of fluid it is)
Pleural aspiration (ultrasound guided procedure) 
-send fluid off for: protein levels, glucose levels, LDH, MC&S & pH

Question 22

Describe the difference between transudate and exudate. What are the main causes of each?

Answer 22

Pleural:serum protein – transudate < 0.5, exudate > 0.5
Transudate = large protein molecules do not pass through the pores in the capillary
Exudate = protein molecules pass through the ‘leaky’ capillary
Main causes:
1) Transudate = congestive cardiac failure, hypoproteinaemia – nephrotic syndrome & liver cirrhosis
2) Exudate = infection (TB, pneumonia), lung malignancy & pulmonary infarction

Question 23

Describe treatment for a pleural effusion

Answer 23

Depending on the cause
In very symptomatic patients – chest aspiration may be indicated
Recurrent effusions (particularly malignant) may require:
-indwelling pleural catheter (IPC) for intermittent drainage
-pleurodesis: obliteration of the pleural space