Respiratory I (Pneumothorax; Pleural effusions; mesothelioma)) Flashcards
What are the most common causes of iatrogenic pneumothorax? [2]
- Pleural aspiration / chest drain insertion for pleural fluid
- Central venous line insertions
State causes of secondary pneumothorax:
-Obstructive airway disease [2]
- Infections [2]
- Suppurative lung disease [3]
- Interstitital lung disease [4]
- Genetic [3]
- Other
Obstructive airway disease:
- COPD
- Asthma
Lung and pleural malignancies
Infection:
- TB
- Pneumonia
Suppurative lung disease:
- Cystic fibrosis
- Bronchiectasis
- Lung abscess
Interstitial lung disease:
- Sarcoidosis
- IPF
- Hypersensitivty pneumonitis
- Pneumoconiosis (any lung disease caused by the inhalation of organic or nonorganic airborne dust and fibers)
Genetic:
- CF
- Marfans
- Birt-Hogg-Dube syndrome
Despite the fact that primary pneumothorax is thought to occur in healthy lungs, there are thought to be predisposing factors that contribute to this pathology. Explain what these are [1]
Air bulla (bubbles on surface of pleura) that weaken the visceral pleura and burst
Uncertain why this happens - possibly due to inflammation
State 3 respiratory and 5 cardiac differential diagnosis
Respiratory:
- PE
- Pneumonia
- Acute exacerbation of respiratory disease
CV:
- MI / ACS
- Pericarditis
- AAA or aortic dissection
- Cardiac tamponade
What do you need to spefically look at on a blood test prior to treating a pneumothorax with a chest drain? [1]
Correct clotting abnormalities (INR ≥1.5 or platelets ≤50 x 10⁹/L) before inserting a chest drain in patients who are not critically unwell
What is the most common finding of an ABG of pneumothorax patient? [1]
respiratory alkalosis is the most common finding
Describe the mangement plan for a primary pneumothorax if the patient has shortness of breath or more than a 2cm rim of air on the chest x-ray: [2]
Be specific
Aspiration with 16-18G cannula; aspirate < 2.5L followed by reassessment
When aspiration fails twice, a chest drain is required
Describe the mangement plan for a primary pneumothorax if the patient has bilateral pneumothorax or is haemodynamically unstable [1]
Chest drain
Describe the location of chest drain procedure [4]
Chest drains are inserted in the “triangle of safety”. This triangle is formed by the:
- 5th intercostal space (or the inferior nipple line)
- Midaxillary line (or the lateral edge of the latissimus dorsi)
- Anterior axillary line (or the lateral edge of the pectoralis major)
The needle is inserted just ABOVE the rib to avoid the neurovascular bundle that runs just below the rib. Once the chest drain is inserted, obtain a chest x-ray to check the positioning.
What should you do to check positioning of chest drain? [1]
Once the chest drain is inserted, obtain a chest x-ray to check the positioning.
How do you know if a chest drain has been successful in its treatment? [1]
During the procedure:
- When the chest drain successfully treats the pneumothorax, air will bubble through the fluid in the drain bottle
- There will be swinging of the water with respiration.
After the procedure:
- Once the pneumothorax resolves, there should be no further bubbling in the drain bottle. The swinging of the water with respiration will also reduce.
Describe two complications of a chest drain
Air leaks around the drain site (indicated by persistent bubbling of fluid, particularly on coughing)
Surgical emphysema (also known as subcutaneous emphysema) is when air collects in the subcutaneous tissue
Label A-C of treatment of primary pneumothorax
State [1] and explain [2] how much air you can aspirate during the managment of a primary pneumothorax with rim > 2 cm and / or breathless?
< 2.5L:
- reduces the risk of re-expansion pulmonary oedema;
- if needs more than 2.5L needs a chest drain anyway
Describe the mangement plan for a secondary pneumothorax if the patient has shortness of breath and 1-2cm rim of air on the chest x-ray [2]
Aspiration with 16-18G cannula; aspirate < 2.5L followed by reassessment
When aspiration fails twice, a chest drain is required
Describe the mangement plan for a secondary pneumothorax if the patient has shortness of breath and / or > 2cm rim of air on the chest x-ray [1]
Chest drain and admit
Describe the mangement plan for a secondary pneumothorax if the patient has no shortness of breath and < 1-2cm rim of air on the chest x-ray [2]
Admit
High flow O2 (15 L)
Observe for 24 hrs (important difference between primary pneumothorax!)
Label A-C for secondary pneumothorax
How long do most pneumothoraces resolve with a chest drain? [1]
What would you call it if after two days there was no resolution? [1]
Should resolve in 2-3 days
If not: called a persistent air leak - call the thoracic surgeons
How do you manage secondary pneumothorax persistent leak? [1]
Risk of surgery is greater: need to consider risk benefit:
- medical pleurodesis: put talc through chest drain (not as effective as surgical pleurodesis & painful)
- Abrasive / surgical pleurodesis (using direct physical irritation of the pleura)
- Open thoracotomy
Describe the pathophysiology of tension pneumothorax [3]
The pleural injury acts as a one-way valve.
As a result, the air can enter the pleural space during inspiration, but is unable to escape during expiration.
Reduces venous return and stops you breathing
Can lead to cardiac arrest
Describe what is meant by swinging and bubbling in a chest drain [2]
If a chest drain is inserted, look out for:
Swinging:
- the fluid in the chest drain tubing moves towards the patient during inspiration (due to reduced intrathoracic pressure during inspiration when the diaphragm descends).
Bubbling:
- the fluid in the chest drain bottle bubbles when the pneumothorax is initially drained (this should stop eventually). The persistence of bubbling for >48 hours may indicate an air leak, which is a connection between the bronchial tree and pleural space (also known as a bronchopleural fistula).21 This may need to be discussed with a thoracic surgeon.
Other than findings on respiratory examination, which observation makes the diagnosis of tension pneumothorax more likely than simple pneumothorax?
Blood pressure
Oxygen saturations
Pain score
Respiratory rate
Temperature
Blood pressure
Hypotension will occur in tension pneumothoraces as a result of cardiac outflow obstruction
A 26-year-old male is admitted to the Emergency Department due to sudden onset dyspnoea and pleuritic chest pain. On examination:
Investigation Result Normal value
Respiratory rate (RR) 24 breaths/min 12–18 breaths/min
Sats 96% on air 94–98%
Blood pressure 120/81 mmHg < 120/80 mmHg
Heart rate (HR) 90 beats/min 60–100 beats/min
Chest clear, some reduced air-entry on right upper zone. His chest X-ray shows a 1-cm pneumothorax on the apex of the right lung.
Which is the next most appropriate treatment for this patient?
Oxygen
Admit the patient for observation
Discharge the patient home
Aspiration
Chest drain
Admit the patient for observation
This young patient with primary pneumothorax requires careful management. According to BTS guidelines, discharge may be considered if the air rim is < 2 cm and the patient is not breathless. For breathless patients, aspiration is attempted. If unsuccessful (> 2 cm or persistent breathlessness), a chest drain is inserted. Close monitoring and reassessment are necessary to prevent complications and ensure prompt intervention.
What are the two criteria need to have when deciding if primary spontaneous pneumothorax can be discharged? [2]
< 2 cm from rim
AND
Not SOB
You are a junior doctor on A+E and your patient has become acutely short of breath. On examination, you become convinced that this patient has a left tension pneumothorax.
Which clinical signs would best support this diagnosis?
Left hyper-resonance, left trachial deviation, absent JVP
Left hyper-resonance, left trachial deviation, raised JVP
Left hyper-resonance, right trachial deviation, raised JVP
Left hypo-resonance, left trachial deviation, absent JVP
Left hyper-resonance, right trachial deviation, absent JVP
You are a junior doctor on A+E and your patient has become acutely short of breath. On examination, you become convinced that this patient has a left tension pneumothorax.
Which clinical signs would best support this diagnosis?
Left hyper-resonance, right trachial deviation, raised JVP
Describe the processes involved in therapeutic paracentesis and chest drain insertion to treat pleural effusion [2]
Therapeutic paracentesis: this involves the removal of 1-1.5 L of pleural fluid via a special drainage kit that can then be removed at the end of paracentesis.
Chest drain insertion: this involves the insertion of a tube (10-14 Fr) into the pleural space to allow drainage over hours to days. Drains are connected to an underwater seal to prevent backflow of air or fluid into the pleural space.
Describe the most common cause of haemothorax? [1]
The most common cause of haemothoraces is following trauma, typically from rib fractures that damage the intercostal vessels, bleeding directly into the pleural cavity.
How do you manage haemothoraxes? [4]
- Sufficient analgesia
- For trauma cases: tranexamic acid
- The majority of haemothorax require the insertion of a surgical chest drain, to evacuate the blood from the pleural cavity
- For patients with large volume blood loss (approx. >1500ml) or continuing moderate volume blood loss (approx. >200ml per hour), surgical exploration should be considered, in attempt to identify and stop the bleeding vessel - usually via VATS
Timing of VATS is crucial when evacuating a haemothorax, ideally being performed within 48-72 hours, to enable successful evaluation and early re-expansion of the lung.
Describe what is meant by a flail segment in a patient with haemothorax [1]
A flail chest is described when a segment of the rib cage breaks due to blunt thoracic trauma and becomes unattached from the chest wall.[1]It can occur when 3 or more ribs are broken in at least two places, although not everyone with this type of injury will develop a flail chest. However, when these injuries cause a segment of the chest to move independently, the generation of negative intrapleural pressure indicates a true paradoxical flail segmen
Describe pleural fluid physiology [3]
Hydrostatic pressure is higher in parietal than the visceral pleura
Oncotic pressures are similar
Net effect:
- Most of fluid coming into the pleural space orignates from the parietal pleura
- Fluid in the pleural space is drained by lymphatic channels
For each of the following, state what can cause them and therefore pleural diseases:
- Increasing capillary permeability [4]
- Increasing pleural permeability [3]
- Decreased lymphatic drainage [2]
- Increased negative pleural pressure [2]
Local factors (referred to as exudates) that cause accumulation of pleural fluid
Increasing capillary permeability:
- Trauma
- Malignancy
- Inflammation
- Infection
- Pancreatitis
Increasing pleural permeability:
- Inflammation
- Malignancy
- PE
Decreased lymphatic drainage
- Malignancy
- Trauma
Increased negative pleural pressure
- Atelectasis (focal lung collapse)
- Mesothelioma
Often a combination of all of these mechanisms
What is the difference between exudative and transudative pleural effusions? [2]
Exudative – a high protein content: more than 30g/L
Transudative – a lower protein content less than 30g/L
Which borders make the triangle of safety? [3]
Describe the diagnostic algorithm for pleural effusion
How do you investigate for mesothelioma? [4]
-
CXR:
either a pleural effusion or pleural thickening - next step is normally a CT thorax
- if a pleural effusion is present fluid should be sent for MC&S, biochemistry and cytology (but cytology is only helpful in 20-30% of cases)
-
local anaesthetic thoracoscopy is increasingly used to investigate cytology negative exudative effusions as it has a high diagnostic yield (around 95%)
if an area of pleural nodularity is seen on CT then an image-guided pleural biopsy may be used
Describe the treatment algorithm for a patient with mesothelioma with inoperable disease [3]
1ST LINE – chemotherapy and/or immunotherapy
CONSIDER – radiotherapy
CONSIDER – palliative procedures + supportive care
- Therapeutic thoracentesis and pleurodesis may provide symptomatic relief.
In patients with inoperable or recurrent mesothelioma, chemotherapy and/or immunotherapy is often given in an attempt to improve quality of life and survival.
