Pneumothorax (RESP) Flashcards
Define pneumothorax.
Collection of air within the pleural space between the lung (visceral pleura) and chest wall (parietal pleura)
What are the different types of pneumothorax? (4)
- primary spontaneous - in patients without underlying lung disease, in the absence of trauma or medical intervention
- secondary spontaneous - complication of underlying lung disease (e.g. COPD, asthma, TB)
- traumatic - caused by penetrating injury to chest (e.g. stabbing, gunshot)
- tension - medical emergency requiring immediate decompression
Who do primary spontaneous pneumothoraxes typically affect?
Tall, thin males
What is a primary spontaneous pneumothorax caused by?
Rupture of a sub-pleural bleb (bulla)
What is important about tension pneumothorax?
- life-threatening variant, complication of one of the other types (primary/secondary spontaneous, traumatic)
- one-way valve, air can enter pleural space but cannot leave hence shifts trachea and can press on heart
- usually due to trauma
What are the signs of tensioning in pneumothorax? (2)
- tracheal deviation away from pneumothorax
- sudden hypoxia and increased ventilation
How does tension pneumothorax cause hypotension?
Mediastinal shift –> cardiac outflow obstruction –> hypotension
How can tension pneumothorax cause death?
Severe hypotension
When should you suspect tension pneumothorax in a hospital setting?
Sudden deterioration following intubation
Describe the epidemiology of primary spontaneous pneumothorax. (2)
- M>F (tall, thin males)
- 16-25 year olds
What are the clinical features of pneumothorax? (3)
- sudden, severe, pleuritic chest pain
- dyspnoea/breathlessness (sudden)
- rapid shallow breathing
How might a tension pneumothorax present differently to another pneumothorax?
- general: dyspnoea and chest pain
- tension pneumothorax: respiratory distress, rapid laboured respirations, cyanosis, excessive diaphoresis (sweating), tachycardia, hypotension
What might you see on examination in pneumothorax? (4 + 2)
- unilateral reduced chest expansion
- unilateral reduced breath sounds
- hyper-resonant percussion
- ipsilateral reduced tactile vocal fremitus
Tension pneumothorax:
- tracheal deviation AWAY from pneumothorax
- haemodynamic instability - tachycardia, hypotension, tachypnoea, cyanosis
What are some risk factors for pneumothorax? (10)
- smoking
- tall & slender body
- male sex
- <40 years
- Fx
- pre-existing lung disease (e.g. COPD, asthma, TB) –> secondary pneumothorax
- recent invasive medical procedure (chest drain)
- chest trauma (rib can puncture lung)
- collagen disorders - Marfan’s syndrome, EDS
- cystic fibrosis
What is the first-line investigation for pneumothorax?
Chest x-ray (order an erect PA CXR in inspiration)
What would you see on CXR in pneumothorax? (3+1)
- absent lung markings
- collapsed lung - visible rim between lung margin and chest wall
- visible pleura
- TENSION - tracheal deviation AWAY from pneumothorax
What investigation is used for patients with pneumothorax who are immobilised following trauma?
Chest ultrasound - requires specialist expertise
When is CT thorax used in pneumothorax?
To identify small pneumothoraces missed by CXR
What might you see on ABG in pneumothorax?
Respiratory alkalosis secondary to hyperventilation (low PaCO2 and PaO2 - done if O2 sats are low)
What are some differential diagnoses for pneumothorax? (9)
- asthma exacerbation
- COPD exacerbation
- pulmonary embolism
- myocardial ischaemia
- pleural effusion
- bronchopleural fistula
- fibrosing lung disease
- oesophageal perforation
- giant bullae
What is the clinical difference between a small and large pneumothorax?
- small: a visible rim of </=2cm between the lung margin and chest wall at the level of the hilum on PA CXR
- large: a visible rim of >2cm between the lung margin and chest wall at the level of the hilum on PA CXR
How do we manage a primary pneumothorax without SOB and <2cm?
Discharge and review as outpatient in 2-4 weeks
How do we manage a primary pneumothorax with SOB or >2cm?
Aspiration (16-18G cannula, aspirate <2.5L)
If unsuccessful –> chest drain
How do we manage a secondary pneumothorax without SOB and <1cm?
- admit for 24h and observe
- high flow oxygen
