Pneumothorax & Pleural Effusion Flashcards
What is a pneumothorax and how is it caused in generals terms?
= the presence of air between the visceral and parietal pleura
Chest wall/ lung breached -> communication pleural space & atmosphere -> air flows from atmosphere to pleural cavity -> until pressures equal -> lung collapses due to unopposed elastic recoil
Causes of a pneumothorax
the lung (commonest by far):
- Primary spontaneous
- secondary to underlying lung disease or trauma (worse)
- iatrogenic (high pressure ventilation/ central line placement)
Through the chest wall (rare):
- trauma
Both the lung and through chest wall (rare):
- trauma e.g. penetrating chest injury
What is a primary spontaneous pneumothorax? Who’s most at risk?
No Kung disease or thoracic trauma
Most cases probably have small sub- pleural bleb or bulla (air filled sac) that bursts allowing air into pleural cavity
Most common: Tall Young Thin Males Smoking increases X9
What is a secondary pneumothorax?
Secondary to:
- underlying lung disease e.g. COPD, asthma (present acute severe do CXR) , bronchiectasis (including cystic fibrosis), lung cancer, pulmonary infections (pneumonia/ TB)
- trauma e.g. fractured rib, severe blunt chest trauma, penetrating chest injuries
- iatrogenic e.g. high pressure ventilation, insertion of central lines/ pacing
Symptoms and signs of a simple pneumothorax
-Sudden onset
-Pleuritic chest pain and breathlessness (sharp when inhaling/ exhaling)
* if present with above consider pulmonary embolism *
+/- history lung disease/ trauma
Signs:
- chest movement reduced on affected size
- hyper- resonant Or resonant percussion on affected side
- vesicular/ bronchiole reduced/ absent breath sounds on affected side
- reduced vocal resonance (say 99)
What would a pneumothorax look like on a CXR?
If right sided:
- right hyperlucent/ darker than normal side as air in pleural space so not lung tissue
- absent Lung markings right beyond edge collapsed lung
- edge collapsed lung seen on right side
Slide 9 and 10 (CT scan)
Treatment of pneumothorax
If asymptomatic:
✅ small pneumothorax = needle aspiration
✅ large = insertion of chest drain
Chest drainage placement in safe triangle (5th ICS mid-axillary line, just ABOVE 6th rib) could then be connected to underwater seal (2cm UW) air moves into water and then inspiration water moves up tube to prevent air moving back into lung
What is a tension pneumothorax? How is it caused?
Any sized pneumothorax causing mediastinal shift and CVS collapse
Can occur due to any aetiology, most often trauma
Occurs when air can enter pleural cavity on inspiration but can’t escape on expiration bc a flap closes (one-way valve)
Slide 14
How is a tension pneumothorax life threatening?
Mediastinal shift compresses normal lung -> increased intrapleural pressure higher than atmospheric for much of respiratory cycle -> venous return impaired -> Cardiac output drops -> hypoxaemia + haemodynamic compromise
Symptoms and signs of a tension pneumothorax
Severe distress
Dyspnoea
Pleuritic chest pain
Fatigue
Signs: Tachycardia Hypotension Raised JVP Deviated trachea Displaced apex beat * above all signs CV collapse * Hyper-resonant percussion note Absent breath sounds
Diagnosis clinical, can’t wait for CXR ->
✅ emergency needle decompression of chest
How can you tell a tension pneumothorax on a CXR?
If tension pneumothorax on right:
- trachea deviated left
- ❤️ displaced left
- right lung hyperlucent with absent lung markings
- edge of collapsed lung visible
How do you treat a tension pneumothorax?
✅ emergency needle decompression of chest
- insert plastic cannula (venflon) into second ICS in mid-clavicular line
- cannula left in place till chest drain inserted (5th ICS mid axillary line) once patient is stable
What is a pleural effusion? Types
XS fluid in pleural cavity - imbalance of normal rate of pleural fluid production and absorption
Can be: transudate or exudate from blood
Haemothorax - fluid is blood e.g. trauma
Chylothorax - fluid is lymph e.g. leak from lymphatic duct trauma
Empyema - fluid is pus
Explain the production and absorption of pleural fluid normally
Normally 2400ml pleural fluid produced each day by parietal pleura - depends on starling forces in systemic capillaries and parietal pleura (e.g. fluid leaves capillary hydrostatic pressure> osmotic blood colloid P, then equal, then reabsorption fluid venous end)
Absorbed lymphatics
When do you get transudate pleural effusion?
Low protein fluid
Increased formation of pleural fluid
Causes:
-Commonest congestive ❤️ failure (increased pressure venous end)
- hypoproteinaemia (reduced colloid oncotic pressure)
- nephrotic syndrome (increased protein loss urine)
- liver failure (reduced protein synthesis in liver cirrhosis
