pneumothorax Flashcards
def pneumothorax
air can move in and out, or hole has just sealed so the air is just there
air in the pleural space (potential space between the vsiceral and parietal pleura)
Other variants depend on the substance in the pleural space (e.g. blood: haemothorax; lymph: chylothorax).
def tension pneumothorax
emergency.
A functional valve lets air enter the pleural space during inspiration, but not leave in expiration
mediastinum pushed over to contralateral hemithorax, kinking and compressing the great veins
unless air rapidly removed - cardiovascular arrest will occur
1 way valve, air goes in but not out = increased pressure in the intrapleural space
causes haemodynamic instability - cause pressure on the mediastinum - tachycardic
aetiology spontaneous pneumothorax
in individuals with previously normal lungs
typically tall thin males
probably by rupture of a subpleural bleb
aetiology secondary pneumothorax
pre-existing lung disease (COPD, asthma, TB, pneumonia, lung carcinoma, cystic fibrosis, diffuse lung disease, lung abscess, lung fibrosis, sarcoidosis)
aetiology traumatic pneumothorax
penetrating injury to chest
often iatrogenic - during subclavian/jugular venous cannulation, thoracocentesis, pleural or lung biopsy, positive pressure assisted ventilation, lung biopsy, transbronchial biopsy
RF for pneumothorax
collagen disorders (eg Marfan’s disease and Ehlers-Danlos syndrome)
young, tall male +- connective tissue disorder
alveoli bleb that rupture
epidemiology pneumothorax
Annual incidence of spontaneous pneumothorax is 9 in 100 000.
20–40 year olds.
Four times more common in males.
sx pneumothorax
may be asymptomatic
sudden onset of breathlessness/chest pain, especially on inspiration
distress with rapid shallow breathing if tension pneumothorax
pts with asthma/COPD may present with a sudden deterioration
mechanically ventilated pts may present with hypoxia or an increase in ventilation pressures
signs of pneumothorax
may be none if pneumothorax is small
signs of resp distress:
- reduced expansion
- hyper-resonance
- reduced breath sounds
signs tension pneumothorax
- trachea shift away from pneumothorax
- severe resp distress
- tachycardia
- hypotension
- cyanosis
- distended neck veins
- increased percussion note
- reduced air entry/breath sounds on the affected side
ix pneumothorax
CXR
- dark area of film where lung markings don’t extend to
- fluid level may be seen if blood present
- in small pneumothoraces, expiratory films may make it more prominent
ABG - see if hypoxaemia - particularly in secondary disease
mx tension pneumothorax
max ox
insert large bore needle (14-16G) with a syringe, partially filled with 0.9% saline into 2nd intercostal space MCL, on side of pneumothorax to relieve pressure
- remove plunger to allow air to start bubbling through the syringe with saline as a water seal
Alternatively, insert a large-bore Venfl on in the same location
insert chest drain
Mx small pneumothorax
(<2cm lung-pleural margin)
if no underlying lung disease, pleural fluid or clinical compromise:
- reassure
- analgesia
mx moderate pneumothorax
(>2cm lung-pleural margin)
aspiration with large bore cannula or catheter with 3-way tap
- insert into 2nd ICS MCL
- up to 2.5L of air can be aspirated (stop if pt coughs or resistance is felt)
- follow up CXR should be performed just after, 2h and 2wk later
- advised to stop diving
chest drain with water seal
- if aspiration fails or if there is fluid in the pleural cavity or after decompression of a tension pneumothorax
- inserted into 4-6th ICS MAL
mx recurrent pneumothorax
chemical pleurodesis (visceral and parietal pleura fusion with tetracycline or talc)
surgical pleurectomy
