Pneumothorax Flashcards
What happens in a tension pneumothorax?
In a tension pneumothorax the tissue forms a one
way valve allowing air to enter the pleural space
and preventing its escape
Why does a tension pneumothorax usually occur?
Due to trauma
How does the tension pneumothorax affect the heart?
The trapped air compresses the heart and reduces venous return by pushing the mediastinum to the opposite side
This compromises circulation
What are the symptoms of pneumothorax?
sharp pain in the chest tachypnoea fast respiratory rate low oxygen saturation low blood pressure
How does the trachea change position in a pneumothorax?
It deviates away from the pneumothorax
What clinical signs can be elicited in a pneumothorax patient?
decreased expansion of the chest
increased percussion note
decreased breath sounds
crunching due to surgical emphysema
How is venous pressure changed in a patient with a pneumothorax?
Raised central venous blood pressure
What is surgical emphysema?
Accumulation of air in subcutaneous tissue due to trauma or surgical procedure
How can surgical emphysema be identified clinically?
touching the skin makes a crackling sound due to the movement of air
How can a pneumothorax be identified on a chest X-ray?
Follow the lung markings and look for the places where they do not reach the periphery
How is a pneumothorax treated?
Aspiration
Using a catheter which has a valve to let air escape and an underwater seal
Air moves from the chest cavity, into the water and then escapes
Why is a water-tight seal important when treating a pneumothorax?
Air escaping in the right direction requires a pressure gradient
water prevents air from re-entering the thorax
If a pneumothorax is bilateral or haemodynamically unstable, how is it treated?
Chest drain
What is the difference between a primary and secondary pneumothorax?
Secondary occurs if the patient is over 50 and has a significant smoking history
Or they have evidence of underlying lung disease on exam or chest X ray
How is a primary pneumothorax treated?
If it is >2cm and the patient is breathless, it is aspirated
Otherwise discharge is considered and it is reviewed in OPD in 2-4 weeks
How is a secondary pneumothorax treated?
If it is >2 cm and the patient is breathless, a chest drain is used and patient admitted
If it is 1 - 2 cm, it is aspirated with a 16-18G cannula
How is a secondary pneumothorax treated if it is less than 1 cm?
Patient admitted and given high flow oxygen
They are observed for 24 hours
How is the “size” of the pneumothorax measured?
It is the interpleural distance at the level of the hilum
Can someone with a non-traumatic pneumothorax fly?
CXR must confirm resolution before flight
Wait 7 days until flight
Can someone with a traumatic pneumothorax fly?
The time period following a full radiographic resolution should be at least 2 weeks
In which types of patients is the risk of pneumothorax recurrence higher?
Those with co-existing lung disease
The risk doesn’t decline significantly for at least a year
Can patients who have had a surgical intervention via thoracotomy fly?
This procedure is likely to be entirely successful so patients can fly once they have recovered from the effects of surgery
What are the 2 types of pneumothorax that can occur without trauma?
Primary spontaneous pneumothorax
Secondary spontaneous pneumothorax
What causes a primary and secondary spontaneous pneumothorax?
Primary - smoking, family history
Secondary - many diseases including COPD/CF
What is the chance of recurrence after a spontaneous pneumothorax?
After the first, there is a 10% chance of recurrence
After a second pneumothorax, the risk increases to 40%
How do spontaneous pneumothoraces usually arise?
From the rupture of small subpleural blebs
What is meant by the safe triangle when inserting a needle into the thorax?
Area of the chest with less chance of complication
The needle must be inserted over a rib to avoid arteries/veins/nerves
