Pneumothorax Flashcards
What is a pneumothorax?
Air between the visceral and parietal pleura
How does a pneumothorax develop?
Normally, the pleural space is slightly negative pressure compared to the atmospheric pressure int eh lungs.
If the lung is damaged, the air in the lung preferentially moves into the pleura which is more negative.
This disrupts the balanced forces that hold the lung in place, and the lung will collapse.
Signs and symptoms of pneumothorax?
Chest pain (pleuritic), dyspnea
Tachycardia
Hypoxia
Hyper-resonance, decreased or absence breath sounds
Tracheal shift (not midline)
Can be asymptomatic
How do you diagnose pneumothorax?
CXR (standard)
High degree of clinical suspicion
US can be useful to rule out PTX in trained hands (not standard)
CT can pick up some small x-ray occult PTX
What are the radiologic features of pneumothorax?
- Area of hyperlucency (absent of lung markings); often at the apex of the lungs because air rises up)
- Reflection of visceral pleua (pleural line) which is smaller than other lung
- May have small effusion (from iatrogenic PTX)
How do we classify pneumothorax?
Primary spontaneous PTX (spontaneous, no underlying disease)
Secondary PTX (people with underlying lung disease)
Iatrogenic PTX (subclavian catheter, pacemaker, etc)
Traumatic PTX (check for rib fractures)
Tension PTX (any of the above can become a tension pneumo)
22 yr old woman with sudden onset chest pain after acupuncture?
Iatrogenic pneumothorax
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75 yr old man with sudden onset pleuritic chest pain and dyspnea, history of COPD?
Secondary PTX
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55 yr old male, asymptomatic
Post pace-maker insertion
CXR show PTX
Iatrogenic PTX
These ones tend to heal very quickly
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What does this CXR show?
Tracheal shift
Nearly complete collapse of left lung
Developing tension PTX
20 yr old male with sudden onset pleuritic chest pain and dyspnea while showering
Spontaneous primary PTX
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What is the cause of primary spontaneous PTX?
Cause: rupture of apical sub-pleural bleb or bullae
If it recurs, it will most likely happen in the first year
Incidence: 1.2-7.4/100,000
What is a bleb in the lungs?
Small blister in the visceral pleura that is weaker than the rest of the pleura
Thoraco-scopic blebs are white
Risk factors for primary PTX?
Tall, slim
Male
Younger age
Smoker
If a female has has a PTX, they are at higher risk for reoccurance than males
Goals of management of pneumothorax?
- Stabilize the patient: ABCs, oxygen
- Manage air in the pleural space
- Prevent recurrence
How do we manage the pleural air?
- Watch and wait; can reabsorb a small amount on its own
- Supplemental O2
- Aspiration
- Chest tube
- Needle decompression
What are the indicators that we should treat a pneumothorax?
- Primary PTX, symptomatic, large (> 3 cm off the apex)
- Tension PTX (hemodynamic compromise)
- Secondary PTX
- Patient is ventilated; increase risk of more air leaking into pleural space
- Complex pleural disease
- Breathlessness indicates the need for a more active intervention
Does every PTX need a chest tube?
NO!
Patients who are not breathless and have a small PTX can be discharged with early out-patient follow up
How does a chest tube work?
Drains air from aroudn the lung, so that the lung can expand again. Done by attaching tube to a collection chamber.
Underwater seal creates a system that allows air out but not back into the pleural space.
Third compartment is a suction chamber, which allows us to control the suction on the pleural space.
When can the chest tube be removed from a PTX patient?
- Air is evacuated from the pleural space, and lung is back up on CXR
- No more air leaking out of the lung; no air bubbling in water chamber (ie. when they cough); clamp the chest tube for 2-4 hrs and CXR to see if patient remains stable
If both of these conditions are satisfied, it is OK to remove the patient’s chest tube.
What is a tension pneumothorax?
Tension PTX - when the air in the pleural space has increased to the point of becoming a positive pressure, that pushes on the rest of the thorax. Causes hemodynamic problems.
Mediastinal shift to the contralateral side
Collapsed lung
Depressed hemidiaphragm on affected side
How does a tension ptx develop?
Tension ptx is when intrapleural pressure exceeds atmospheric pressure.
Can occur if a person has a sort of one-way valve in the lung, that only allows air INTO the pleural space, not back out.
Can occur if a patient has positive pressure ventilation.
V/Q mismatch –> profound hypoxia
Treat with a needle, to relieve the pressure. 2nd interspace, mid clavicular line. Can hear the pressure relieved with a hiss through the needle.
How do we diagnose tension ptx?
Clinical diagnosis
High degree of suspicion
hyper-resonant to affected side
Diminished/absent breath sounds to affected side
Tracheal deviation to contralateral side; palpate on PE
Management of tension ptx?
Medical emergency!
Decompression!!! Large bore needle 2nd intercostal space, mid clavicular line
Chest tube with water seal (like regular ptx)
