PNEUMOTHORAX Flashcards
What is a pneumothorax?
Collection of air in the pleural cavity resulting in collapse of the lung on the affected side.
When is it a medical emergency?
Tension pneumothorax.
Becomes a one-way valve. Lung collapses. Increased pressure on heart. Cannot compensate. Can lead to death
More common in males or females?
Males (6:1)
Young males
What is the incidence
Incidence primary spontanous pneumothorax is 24/100,000/year in men and 9.9/100,000 for women in England and Wales
When does PSP (primary spontaneous pneumothorax) mainly occur?
occurs most in 20s and rarely over 40.
When does SSP (secondary spontaneous pneumothorax) mainly occur?
occurs as a complication of underlying lung disease. SSP occurs most in over 60s.
Aetiology
- Often spontaneous due to rupture of a sub pleural bulla
- Respiratory disease: Asthma, COPD, TB, Pneumonia, Lung abscess, Carcinoma, CF, Lung fibrosis, Sarcoidosis
- CT disorder: Marfaans, Ehlers Danlos
- Trauma
- Iatrogenic – subclavian CVP line insertion, pleural aspiration or biopsy, Percutaneous liver biopsy, positive pressure ventilation
Spontaneous pneumothorax
rupture of pleural bleb, usually apical and is thought to be due to congenital defects in the CT of the alveolar wall. Both lungs affected with equal frequency
o occurs in healthy people; tall, thin, young males more at risk
o Primary spontaneous – Secondary spontaneous
o Underlying lung disease – rupture of bulla or cyst
o Catamenial – occurs at time of menstruation; endometriosis is underlying pathology
o Traumatic/Iatrogenic
Tension pneumothorax
is when air is sucked into the pleural space during inspiration but not expelled during expiration. Usually involves a valvular mechanism. This means that the pressure remains +ve throughout breathing deflating the lungs further, causing a mediatinum shift and venous return to the heart decr. Tension pneumothorax occurs when opening allowing air into pleural space acts as one-way valve so with each breath more air enters but none can escape. This causes a continual positive pressure in the pleura causing the lung to deflate further causing mediastinal shift.
What signs do you diagnose tension pneumothorax with?
The classic signs of a tension pneumothorax are deviation of the trachea away from the side with the tension, a hyper-expanded chest, an increased percussion note and a hyper-expanded chest that moves little with respiration. The central venous pressure is usually raised, but will be normal or low in hypovolaemic states.
Which way is the trachea deviated?
Away from the side of the pneumothorax
What are the risk factors?
- Male
- Tall – Marfan’s more at risk
- Smoking – 12% increased risk
- Family history
- Underlying lung disease
What symptoms?
- Often asymptomatic especially in PSP – tends to be symptomatic in SSP even if small
- Sudden onset dyspnoea and/ or pleuritic chest pain (pain when you breathe in)
- SOB – especially in SSP because less reserve
- Mechanically ventilated pts may present with hypoxia or an incr in ventilation pressures
What signs?
- Distressed
- Sweating
- Dyspnoea
- Cyanosis
- Tachycardia – over >135 suggests tension
- Pulsus paradoxicus – indicates severe
- Hypotension – indicates tension
- Raised JVP – indicates tension
- Tracheal deviation – towards in simple, away from in tension
- Reduced expansion
- Decreased/no breath sounds (on affected side)
- Hyperresonant to percussion
What investigations would you do?
CXR
ABG
What are you looking for on CXR?
- Look for collapsed lung border with black edges
- Should not be performed if suspect a NOT in tension pneumothorax – urgent treatment required
- with expiratory film – look for area devoid of lung markings, peripheral to the edge of the collapsed lung
What would you use an ABG?
hypoxia; more likely in SSP
What are the treatment options?
Chest drain
Aspiration
Where do insert a chest drain?
insertion into ‘safe traingle’ (lateral border of pec major, anterior border latissimus, line superior to horizontal level of nipple, apex is axilla).
Treating tension pneumothorax?
insert large bore cannula into 2nd intercostal space mid-clavicular line or safe triangle. Then proceed to formal chest drain insertion.
Treating with aspiration
- Insert 16G cannula in pleural space. Remove needle and connect cannula to 3 way tap and 50mL syringe
- Aspirate up to 2.5L air
- Stop if feel resistance or pt coughs excessively
Differentials
Pleural effusion – slower onset; dull to percussion
PE – haemoptysis; more commonly affects lower rather than upper lung; loud 2nd sound in pulmonary area
Chest pain
Prognosis
Rate of recurrence is high: 54% in first 4 years following PSP.
Complications
Risk of treatment: Chest drain – thoracic or abdo organ injury, lymphatic drainage – therefore chylthorax, damage to long thoracic N – winged scapula. Rarely arrhythmia
