Pneumothorax

Question 1

Describe the pleural space

Answer 1

-Visceral pleura warps tightly around the lungs and connects to parietal pleura at mediastinum at hilum
-Parietal pleura wraps rightly around chest wall
-Between, only 1mm of fluid to allow frictionless movement throughout respiratory cycle
-The pleural space has negative pressure relative to atmosphere- pressure changes throughout resp cycle

Question 2

The clinical importance of the pleural space

Answer 2

-Pleural space= self-contained compartment that air can build up in (air can leak from a defect in the lung to pleural space)
-A connection between the normal pleural space and the atmosphere would result in air being sucked into the space

Question 3

What is a pneumothorax?

Answer 3

Pneumothorax is a condition characterized by the accumulation of air in the pleural space, resulting in the partial or complete collapse of the affected lung.

Question 4

Risk factors for primary spontaneous pneumothorax

Answer 4

-Typically, young and male (6:1)
-Tall, thin: greater pressure gradient
-Smoking increases risk (20:1) more for males than females
-Apical blebs/ emphysema like changes (ELCs)- rupture creating air leak
-Cannabis
-Check for FHx of PTX (folliculin gene disorders)

Question 5

Presentation of primary spontaneous pneumothorax

Answer 5

-Often acute but can be subacute- pleurisy, SOB, cough
-Presence of SOB crucial to management
-History not reliable indicator of size

Occurs without underlying lung disease, often in tall, thin, young individuals. PSP is associated with the rupture of subpleural blebs or bullae.

Question 6

Signs of primary spontaneous pneumothorax

Answer 6

-Reduced expansion
-Hyper-resonant
-Reduced breath sounds and vocal resonance
-Tracheal deviation and mediastinal shift (tension pneumothorax)

Question 7

X-Ray of PSP

Answer 7

-Lung edge identified
-Loss of lung markings

Question 8

Causes of secondary spontaneous pneumothorax

Answer 8

-Any chronic lung disease
-Emphysema 60%
-Asthma
-ILD (edges of lung)
-CF
-Infections (TB, PCP)
-Rare: LAM, Histiocytosis, BHD
=Multicystic lung disease
-Associations: Catamenial, Marfans
=Catamenial pneumothorax is the cause of 3-6% of spontaneous pneumothoraces occurring in menstruating women. It is thought to be caused by endometriosis within the thorax.

traumatic pneumothorax: results from penetrating or blunt chest trauma, leading to lung injury and pleural air accumulation.
iatrogenic pneumothorax: occurs as a complication of medical procedures, such as thoracentesis, central venous catheter placement, ventilation, including non-invasive ventilation or lung biopsy.

Question 9

Clinical features of pneumothorax

Answer 9

Symptoms tend to come on suddenly:
dyspnoea
chest pain: often pleuritic

Signs
hyper-resonant lung percussion
reduced breath sounds
reduced lung expansion
tachypnoea
tachycardia

In tension pneumothorax:
respiratory distress
tracheal deviation away from the side of the pneumothorax
hypotension

Question 10

Considerations for management of any PTX

Answer 10

-Breathlessness
-Hypoxia
-Haemodynamic compromise
-PTX size
-Underlying lung disease (how well/ poorly is PTX tolerated?)

the BTS define minimal symptoms as ‘no significant pain or breathlessness and no physiological compromise’
no or minimal symptoms → conservative care, regardless of pneumothorax size
symptomatic → assess for high-risk characteristics

Question 11

Assessment for high-risk characteristics in symptomatic pneumothorax

Answer 11

-High-risk characteristics are defined as follows:
=haemodynamic compromise (suggesting a tension pneumothorax)
=significant hypoxia
=bilateral pneumothorax
=underlying lung disease
=≥ 50 years of age with significant smoking history
=haemothorax

-If no high-risk characteristics are present, and it is safe to intervene, then there is a choice of intervention:
=conservative care
=ambulatory device
=needle aspiration

-If high-risk characteristics are present, and it is safe to intervene → chest drain

Question 12

How is safety or intervention determined?

Answer 12

-before a needle aspiration/chest drain insertion, the safety of intervention should be assessed
-this depends on the clinical context, but is usually:
=2cm laterally or apically on chest x-ray, or
=any size on CT scan which can be safely accessed with radiological support

Question 13

Overview of conservative care

Answer 13

-patients with a primary spontaneous pneumothorax that is managed conservatively should be reviewed every 2-4 days as an outpatient
-patients with a secondary spontaneous pneumothorax that is managed conservatively should be monitored as an inpatient
-if stable, follow-up in the outpatients department in 2-4 weeks

Question 14

Ambulatory care of pneumothorax

Answer 14

-An example of an ambulatory device is the Rocketµ Pleural Vent„
-it includes an 8FG catheter mounted on an 18G needle and a pigtail catheter to minimize the risk of occlusion
-ambulatory devices typically have a one-way valve and vent to prevent air and fluid return to the pleural space while allowing for controlled escape of air and drainage of fluid
-many devices also have an indication diaphragm that signals when the catheter tip enters the pleural space and continues to fluctuate with respiration, aiding in the assessment of pneumothorax resolution

Question 15

When should a PTX require a chest drain?

Answer 15

-If bilateral/ haemodynamically unstable
-Secondary pneumothorax size >2cm or breathless

daily review as an inpatient
remove drain when resolved
discharge and follow-up in the outpatients department in 2-4 weeks

Question 16

When should a PTX be aspirated?

Answer 16

-Primary pneumothorax size >2cm and/or breathless
-Secondary pneumothorax size 1-2cm

a chest drain should be inserted if needle aspiration of a pneumothorax is unsuccessful
if resolved, discharge and follow-up in the outpatients department in 2-4 weeks

Question 17

How do we measure pneumothorax size?

Answer 17

-Measured from chest wall to lung edge at level of hila
-2cm= 50% pneumothorax

Question 18

Management of persistent/recurrent pneumothorax

Answer 18

If a patient has a persistent air leak or insufficient lung re-expansion despite chest drain insertion, or the patient has recurrent pneumothoraces, then video-assisted thoracoscopic surgery (VATS) should be considered to allow for mechanical/chemical pleurodesis +/- bullectomy.

Question 19

Surgical techniques for pneumothorax

Answer 19

-Therapeutic aspiration- 2nd ICS mid clavicular line
-Seldinger Intercostal Drain (needle over guide wire technique)
=Surgical emphysema?

Question 20

Intercostal Chest Drain Review

Answer 20

• Swinging: (normal movement with respiratory cycle)
• Swinging and Bubbling: (draining air)
• Neither (Tube blocked and in need of flush,
  kinked, pneumothorax resolved)
• Suction (2.5-5kPa)

Question 21

Indication for thoracic surgery

Answer 21

-Video-assisted thoracoscopic surgery (VATS)
-Bleb removal, apical stapling, talc pleurodesis, abrasion
-Where chest drainage not successful or electively for a patient with recurrent PTX or bilateral PTX

Question 22

Advice for after PTX

Answer 22

-No scuba-diving: Diving should be permanently avoided unless the patient has undergone bilateral surgical pleurectomy and has normal lung function and chest CT scan postoperatively.
-Stop smoking
-No flying for at least 2 weeks. The British Thoracic Society used to recommend not travelling by air for a period of 6 weeks but this has now been changed to 1 week post check x-ray
-No heavy-lifting (work or recreational)
-25% patients suffering PSP will have recurrence

Question 23

Causes of traumatic PTX

Answer 23

-Iatrogenic
=CT guided biopsies
=Central venous lines
=Pacemakers

-Chest trauma (RTA)

-Barotrauma
=Mechanical ventilation
=Diving

Question 24

What is tension pneumothorax?

Answer 24

Tension pneumothorax is a life-threatening condition characterised by the accumulation of air in the pleural space under positive pressure, leading to the collapse of the lung on the affected side and a shift of the mediastinum towards the contralateral side. This process results in impaired venous return to the heart and subsequent reduction in cardiac output, posing a significant risk of cardiovascular collapse.

Question 25

Causes of tension pneumothorax

Answer 25

-Traumatic
=penetrating or blunt chest trauma
-Iatrogenic
=thoracentesis
=central venous catheter placement
=positive pressure mechanical ventilation
-Spontaneous
=particularly those with underlying lung diseases e.g. COPD or cystic fibrosis
=lung blebs (small blisters on the lung surface) can rupture spontaneously, causing air to leak into the pleural space

Question 26

Clinical features of tension pneumothorax

Answer 26

acute onset of dyspnoea
pleuritic chest pain
tachypnoea
signs:
hyperresonance on percussion, diminished breath sounds on the affected side
tracheal deviation away from the affected side
in severe cases, patients may also exhibit signs of shock such as hypotension and tachycardia.

Question 27

Diagnosis of tension pneumothorax

Answer 27

Tension pneumothorax should ideally be diagnosed clinically - emergency treatment should not await confirmation on imaging.

Question 28

Management of tension pneumothorax

Answer 28

the aim is decompression of the pleural space
this is initially performed via needle thoracostomy, inserting a cannula into the second intercostal space in the midclavicular line on the affected side
this is followed by the placement of a chest drain (tube thoracostomy) in the safe triangle of the chest to allow continuous drainage of air.