Lecture 16: Pneumothorax and pleural effusion Flashcards
What is a pneumothorax?
Air within the pleural cavity
-if you get a disruption of the pleura, air flows from a higher pressure outside the chest, to the negative pressure in pleural cavity
=lung collapse
What is the difference between simple and tension pneumothorax?
Simple: rim of air in the pleural cavity which doesn’t cause any impairment (haemodynamically stable patients)
Tension: hypotensive, tachycardic, causes haemodynamic instability. Caused by one way flow of air
What is the difference between primary and secondary pneumothorax?
Primary: no underlying lung pathology
Risk factors- male, young, family history of pneumothorax, smoking
Secondary: underlying lung pathology e.g. COPD, asthma, bronchiectasis, lung cancer, infections, RA
What are the causes of pneumothorax?
Spontaneous- due to subpleural blebs/bulla bursting (air filled sacs)
Iatrogenic- insertion of central lines/pacing wires
Trauma- severe chest wall injury (stab/gunshot), rib fractures (puncture the visceralpleura)
What are the different types of pneumothorax?
Tension VS Simple
- simple can be subdivided into Primary (usually spontaneous) VS Secondary
- primary and secondary can turn into tension pneumothorax
What are the presenting symptoms and signs of simple pneumothorax?
- chest pain (pleuritic- breathing in you get a stabbing pain, as air rushes in irritating the pleural lining)
- sometimes SOB
- history of trauma/lung disease
- tracheal deviation normal
- chest movement reduced on affected side due to collapsed lung
- percussion is hyper-resonant on affected side
- ausciltation can’t hear breath sounds on affected side due to collapsed lung
What are the radiological findings of a simple pneumothorax?
- can see collapsed lung borders
- absent lung markings
- hyper-lucent (appears darker)
How do you treat simple pneumothorax?
- conservative treatment (for small pneumothorax)
- pleural aspiration (needle into cavity to drain air)
- chest drain insertion (ultrasound guided)
How do you insert a chest drain?
In the safe triangle Borders Superior: base of axilla Inferior: 6th rib/5th intercostal space Anterior: lateral edge of pec major Posterior: lateral edge of latissimus dorsi
End of chest drain is put into an underwater seal
What is an underwater seal?
Exhales
-air leaves and comes out as bubbles and leaves the bag to open air
Inhales
-negative pressure inside pleural cavity, the water level rise, this prevents air entering
How does a tension pneumothorax occur?
- when patient exhales, the air doesn’t leave, as the pleural lining acts as a valve and allows only a one way flow of air
- causes a build up of air
- compress on IVC/SVC which reduces blood flow to heart= tachycardic, low bp, cyanotic, hypoxaemic
What are the presenting signs and symptoms of a tension pneumothorax?
Similar to simple pneumothorax, but also:
- respiratory distress
- cyanosis
- marked tachycardia
- marked hypoxaemia
Tracheal deviation- away from affected side
Chest movement- reduced on affected side
Auscultation- absent on affected side due to collapsed lung
No time to do percussion/resonance findings
How do you treat a tension pneumothorax?
Emergency needle decompression
-second intercostal space in the mid-clavicular line
Where does the first rib lie?
Just below the clavicle
What is a pleural effusion?
Excess fluid in the pleural cavity (imbalance between rate of production from systemic capillaries and absorption via lymphatic system)
What is a simple effusion?
When the fluid is pleural fluid (can be transudate/exudate)
What other fluids can fill the pleural cavity?
Haemothorax: blood e.g. trauma
Chylothorax: lymph
Empyema: pus e.g. secondary to resistant infection
What are the presenting signs and symptoms of a pleural effusion?
- SOB gradual onset
- pleuritic chest pain due to irritation of pleural lining
Tracheal deviation: away from affected side (only on a large pleural effusion)
Chest movement: reduced on affected side
Percussion: ‘stony’/dull on affected side
Breath sounds: reduced/absent on affected side
Vocal resonance: reduced on affected side
What do you see upon radiological findings for a pleural effusion?
Meniscal line- top of fluid line
What causes simple effusion?
Transudate: -congestive cardiac failure -hypoproteinaemia (fluid leaves capillaries): nephrotic syndrome/liver cirrhosis Exudate: -infection (TB/pneumonia) -lung malignancy -pulmonary infarction
What causes haemothorax and chylothorax?
Trauma
How do you further investigate a simple pleural effusion?
Pleural aspiration using ultrasound
-send fluid off for protein/glucose levels, LDH (lactate dehydrogenase), pH, gram stain
How do we figure out whether the fluid in a simple effusion is transudate or exudate?
Light's criteria Transudate: -not many protein molecules Exudate: -lots of protein molecules passing through capillaries
How do you treat pleural effusion?
Depends on cause
- in very symptomatic patients, chest aspiration may be needed
- recurrent effusions may require: IPC (indwelling pleural catheter for intermittent drainage), pleurodesis (obliteration of pleural cavity)
