Respiratory I (Pneumothorax; Pleural effusions; mesothelioma))

Question 1

What are the most common causes of iatrogenic pneumothorax? [2]

Answer 1

1. Pleural aspiration / chest drain insertion for pleural fluid
2. Central venous line insertions

Question 2

State causes of secondary pneumothorax:

-Obstructive airway disease [2]
- Infections [2]
- Suppurative lung disease [3]
- Interstitital lung disease [4]
- Genetic [3]
- Other

Answer 2

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

Question 3

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]

Answer 3

Air bulla (bubbles on surface of pleura) that weaken the visceral pleura and burst

Uncertain why this happens - possibly due to inflammation

Question 4

State 3 respiratory and 5 cardiac differential diagnosis

Answer 4

Respiratory:
- PE
- Pneumonia
- Acute exacerbation of respiratory disease

CV:
- MI / ACS
- Pericarditis
- AAA or aortic dissection
- Cardiac tamponade

Question 5

What do you need to spefically look at on a blood test prior to treating a pneumothorax with a chest drain? [1]

Answer 5

Correct clotting abnormalities (INR ≥1.5 or platelets ≤50 x 10⁹/L) before inserting a chest drain in patients who are not critically unwell

Question 6

What is the most common finding of an ABG of pneumothorax patient? [1]

Answer 6

respiratory alkalosis is the most common finding

Question 7

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

Answer 7

Aspiration with 16-18G cannula; aspirate < 2.5L followed by reassessment

When aspiration fails twice, a chest drain is required

Question 8

Describe the mangement plan for a primary pneumothorax if the patient has bilateral pneumothorax or is haemodynamically unstable [1]

Answer 8

Chest drain

Question 9

Describe the location of chest drain procedure [4]

Answer 9

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.

Question 10

What should you do to check positioning of chest drain? [1]

Answer 10

Once the chest drain is inserted, obtain a chest x-ray to check the positioning.

Question 11

How do you know if a chest drain has been successful in its treatment? [1]

Answer 11

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.

Question 12

Describe two complications of a chest drain

Answer 12

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

Question 13

Label A-C of treatment of primary pneumothorax

Answer 13

Question 14

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?

Answer 14

< 2.5L:
- reduces the risk of re-expansion pulmonary oedema;
- if needs more than 2.5L needs a chest drain anyway

Question 15

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]

Answer 15

Aspiration with 16-18G cannula; aspirate < 2.5L followed by reassessment

When aspiration fails twice, a chest drain is required

Question 16

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]

Answer 16

Chest drain and admit

Question 17

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]

Answer 17

Admit
High flow O2 (15 L)
Observe for 24 hrs (important difference between primary pneumothorax!)

Question 18

Label A-C for secondary pneumothorax

Answer 18

Question 19

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]

Answer 19

Should resolve in 2-3 days
If not: called a persistent air leak - call the thoracic surgeons

Question 20

How do you manage secondary pneumothorax persistent leak? [1]

Answer 20

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

Question 21

Describe the pathophysiology of tension pneumothorax [3]

Answer 21

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

Question 22

Describe what is meant by swinging and bubbling in a chest drain [2]

Answer 22

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.

Question 23

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

Answer 23

Blood pressure

Hypotension will occur in tension pneumothoraces as a result of cardiac outflow obstruction

Question 24

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

Answer 24

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.

Question 25

What are the two criteria need to have when deciding if primary spontaneous pneumothorax can be discharged? [2]

Answer 25

< 2 cm from rim AND Not SOB

Question 26

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

Answer 26

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**

Question 27

Describe the processes involved in therapeutic paracentesis and chest drain insertion to treat pleural effusion [2]

Answer 27

**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.

Question 28

Describe the most common cause of haemothorax? [1]

Answer 28

The most common cause of haemothoraces is following **trauma**, typically from **rib fractures that damage the intercostal vessels**, bleeding directly into the pleural cavity.

Question 29

How do you manage haemothoraxes? [4]

Answer 29

- 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.*

Question 30

Describe what is meant by a flail segment in a patient with haemothorax [1]

Answer 30

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

Question 31

Describe pleural fluid physiology [3]

Answer 31

**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**

Question 32

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]

Answer 32

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** ## Footnote Often a combination of all of these mechanisms

Question 33

What is the difference between exudative and transudative pleural effusions? [2]

Answer 33

**Exudative** – a high protein content: **more than 30g/L** **Transudative** – a lower protein content **less than 30g/L**

Question 34

What is the most common exudatate cause of pleural effusion Pneumonia TB Mesolethioma PE Pancreatitis

Answer 34

What is the most common exudatate cause of pleural effusion **Pneumonia** TB Mesolethioma PE Pancreatitis

Question 35

Describe the clinical presentation of a patient with pleural effusion [5]

Answer 35

**asymptomatic** **'shoulder pain / heaviness'** **dyspnoea** **non-productive cough** **pleuritic chest pain**

Question 36

What is the most common cause of pleural effusion? [1]

Answer 36

Heart failure

Question 37

State the 4 most common causes of pleural effusion [4] State if they are exudative or transudative [4]

Answer 37

**Heart failure** (transudative **Pneumonia** (called parapneumonic effusions; exudative **Malignancy** (most commin in patients > 50; exudative **Recent CABG**; exudative

Question 38

What examination findings would suggest pleural effusion? [5]

Answer 38

**Decreased chest expansion** **Decreased VF** **Tracheal deviation** **Stony dull percussion** **Reduced breath sounds**

Question 39

What are the most common [5] and more rare [7] causes of exudate pleural effusion

Answer 39

Common: * **Parapneumonic** * **Malignancy** * **PE** * **RA** * **Mesothelioma** More rare: - Drugs - Empyema - TB - Pancreatitis - Oesophageal rupture - Post cardiac injury (Dresslers syndrome) - Post CABG - Benign aspestos related effusions

Question 40

Describe how you determine if pleural fluid protein is an exudate or transudate if the protein is borderline (25 - 30g/L) OR if is abnormal serum criteria [3]

Answer 40

Use **Light's criteria**: Pleural fluid is an exudate if one of the following is met: - Pleural fluid protein / serum protein > **0.5** - Pleural fluid LDH / serum LDH **> 0.6** - **Pleural fluid LDH** greater than **2/3** of the **normal upper limit of the serum LDH** | Really important to know to help narrow the differential diagnosis

Question 41

State 5 drugs that cause exudative pleuritic effusion

Answer 41

**nitrofurantoin** **valproate** **propylthiouracil** **dantrolene** (used for motor neurone) **methotrexate**

Question 42

State common [4] and less common [3] causes of transudative pleuritc effusion

Answer 42

Common: * **LVF** * **Cirrhotic liver disease** * **Peritoneal dialysis** * **Nephrotic syndrome** Less common: - **Constrictive pericarditis** - **hypothyroidism** - **Meigs' syndrome**

Question 43

Describe the different investigations might conduct for pleural effusion [5]

Answer 43

**CXR** **Pleural ultrasound**: useful locating an area of fluid collection for thoracentesis, especially if the effusion is loculated or small. **Pleural fluid analysis** **Chest CT** **Pleural biospy** **VATS**

Question 44

Describe the clinical presentation of Meig's syndrome [3]

Answer 44

TOM TIP: Meigs syndrome involves a triad of a : - **benign ovarian tumour** (usually a fibroma) - **pleural effusion** - **ascites**. This often appears in exams. The pleural effusion and ascites resolve with the removal of the tumour.

Question 45

In some causes of pleural effusions, RBC might be found in the pleural fluid. State the causes where this could occur [4]

Answer 45

**malignancy** **trauma** **parapneumonic effusions** **pulmonary embolism**

Question 46

A raised lymphocyte count in pleural fluid would most likely indicate which two causes of pleural effusion? [2]

Answer 46

If the lymphocyte population is >90%, **lymphoma** and **TB** are the two most likely diagnoses.

Question 47

Which borders make the triangle of safety? [3]

Answer 47

Question 48

How would pH analysis of pleural fluid help to determine cause? [3]

Answer 48

**< 7.20** in **complicated parapneumonic effusion & empyema**, **rheumatoid** **arthritis**, or **advanced malignancy**

Question 49

How would glucuose analysis of pleural fluid help to determine cause? [4]

Answer 49

**Low glucose** (< 3.3 mmol/L (60 mg/dL)) in **empyema**, **rheumatoid** **arthritis**, **TB**, and **malignancy**

Question 50

Describe the diagnostic algorithm for pleural effusion

Answer 50

Question 51

What size needle [1] and syringe [1] should be used for pleural aspiration?

Answer 51

A **21G needle** and **50ml syringe** should be used

Question 52

Which pathologies would a raised amylase in pleural fluid indicate? [2]

Answer 52

**pancreatitis**, **oesophageal** **perforation**

Question 53

What pathologies would a pleural fluid finding indicate if there was: - Low glucose [2] - Raised amylase [2] - Heavy blood staining? [3]

Answer 53

Other characteristic pleural fluid findings: **low glucose**: - **rheumatoid arthritis** - **tuberculosis** **raised amylase**: - **pancreatitis** - **oesophageal perforation** **heavy blood staining**: - **mesothelioma** - **pulmonary embolism** - **tuberculosis**

Question 54

A pleural effusion is found to have raised amylase after a pleural tap. What is the most likely cause of this? **What is the other differential? [1]** TB RA Mesothelioma PE Oesophageal perforation

Answer 54

**Oesophageal perforation** or **Pancreatitis**

Question 55

A pleural effusion is found to have low blood glcose after a pleural tap. What is the most likely cause of this? [2] TB RA Mesothelioma PE Oesophageal perforation

Answer 55

**TB** **RA**

Question 56

A 74-year-old male is found to have bilateral pleural effusion. A sample is aspirated and is found to contain 15 g/l of protein. Based on this finding, what is the possible cause of the pleural effusion? Inflammation from SLE Pancreatitis Renal failure Right-sided mesothelioma Right-sided pneumonia

Answer 56

**Renal failure**

Question 57

Name two endocrine causes of transudative pleural effusions [2]

Answer 57

**Hypothyroidism** **Ovarian hyperstimulation syndrome**

Question 58

# Pleu Explain the characteristics of pH; LDH and CO2 in empyema caused pleural effusion [6]

Answer 58

- **low glucose** because bacteria use it for respiration - **low pH** because bacteria producing CO2 in repsiration - **high LDH** because lactate dehydrogenase is needed for the bacteria to convert glucose into energy

Question 59

Which groups should you consider pleural infections in? [4]

Answer 59

* **Slow to respond pneumonias** * **Pleural effusion with fever** * **Malaise/weight loss** * **High risk groups**

Question 60

Name some high risk patient groups for pleural infusion [5]

Answer 60

o Diabetes o Excess alcohol intake o Gastro-oesophageal reflux (GORD) o IVDU o Aspiration and poor dental hygiene

Question 61

Which investigations would you perform for pleuritc infection? [4]

Answer 61

Diagnostic pleural tap * Blood culture * Chest ultrasound * Chest CT chest

Question 62

State the difference in investigational findings for: - simple parapneumonic effusion [4] - complicated parapneuomic effusion [3] - Empyema [3]

Answer 62

**simple parapneumonic effusion**: - Clear, sterile fluid - Normal pH - Normal glucose - Normal LDH **complicated parapneuomic effusion**: - Fluid infected, but not purulent - pH < 7.2 - Glucose < 2.2 - LDH > 1000 - Gram stain may be positive **Empyema**: - Pus in pleural space - Multi-loculated - Gram stain may be positive

Question 63

How would you treat the following? [3] - simple parapneumonic effusion - complicated parapneuomic effusion - Empyema

Answer 63

- simple parapneumonic effusion: **Abx** - complicated parapneuomic effusion: **chest drain** - Empyema: **chest drain**

Question 64

Describe the clinical presentation of mesothelioma patients [5]

Answer 64

**Dyspnoea**, **weight loss** **chest wall pain** **Clubbing** 30% present as **painless pleural effusion** **fatigue, profuse sweating, weight loss, anorexia** and **difficulty in swallowing** become common as the disease **progresses** presentation and diagnosis often occur at an advanced stage and the prognosis for most patients is extremely poor

Question 65

How do you investigate for mesothelioma? [4]

Answer 65

1. **CXR**: either a **pleural effusion** or **pleural thickening** 2. next step is normally a **CT thorax** 3. 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) 4. **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

Question 66

Which is the most common histological type of mesothelioma? [1] Name two other types

Answer 66

**Epitheloid** (50%) **Mixed** **Sarcomatoid**

Question 67

Describe the management of mesothelioma [5]

Answer 67

**Pleural effusions** - **Drainage** & **pleurodesis** (medical or surgical) **Radiotherapy** - To reduce chest wall invasion risk & pain relief **Chemotherapy** - **Cisplatin** with **Pemetrexed** or **Gemcitibine** **Surgery** - selected cases only (high mortality) * **Pain relief** * **Palliative Care**

Question 68

Describe chemotherapy that can be used for mesothelioma [3]

Answer 68

* **Chemotherapy** - **Cisplatin** with **Pemetrexed** or **Gemcitibine**

Question 69

Describe the treatment algorithm for a patient with mesothelioma with operable disease [3] | BMJ BP

Answer 69

**1ST LINE: surgery** - **extra-pleural pneumonectomy [EPP]**: *removes parietal and visceral pleura* - **pleurectomy with decortication** *pleurectomy removes the lining around the lung (the pleura). Decortication removes tumors or fibrous tissue from the surface of the lung*. **PLUS –** **pre- and/or postoperative chemotherapy**: - **cisplatin** AND - **pemetrexed** **CONSIDER – radiotherapy** - **Post-extrapleural pneumonectomy (EPP) radiotherapy (RT)**

Question 70

Describe the treatment algorithm for a patient with mesothelioma with inoperable disease [3]

Answer 70

**1ST LINE – chemotherapy and/or immunotherapy** **CONSIDER – radiotherapy** **CONSIDER – palliative procedures + supportive care** - Therapeutic thoracentesis and pleurodesis may provide symptomatic relief. ## Footnote In patients with inoperable or recurrent mesothelioma, chemotherapy and/or immunotherapy is often given in an attempt to improve quality of life and survival.

Question 71

What is meant by asbestosis? [1]

Answer 71

Asbestosis refers to **chronic, diffuse, interstitial fibrosis** of the lung related to **asbestos** **exposure**. *Asbestos is fibrogenic, meaning it causes lung fibrosis. It is also oncogenic, meaning it causes cancer.*

Question 72

The effects of asbestos usually take several decades to develop. Asbestos inhalation causes several problems. What are they? [4]

Answer 72

**Lung fibrosis** **Pleural thickening** and **pleural plaques** **Adenocarcinoma** **Mesothelioma**

Question 73

What is the difference between length of asbestos exposure between abestos and mesothelioma? [1]

Answer 73

The **severity of asbestosis** **IS** related to the **length of exposure**. This is in contrast **Mesothelioma**: even **very** **limited** exposure can cause **disease**. The latent period is typically 15-30 years.

Question 74

Asbestosis typically causes fibrosis in which lobes? [1]

Answer 74

Asbestosis typically causes **lower lobe fibrosis.**

Question 75

Which conditions would you not perform a needle aspiration and go straight to a chest drain to manage a pneumothorax? [6]

Answer 75

* **Haemodynamic compromise** (suggesting a tension pneumothorax) * **Significant hypoxia** * **Bilateral pneumothorax** * **Underlying lung disease** * **≥ 50 years of age with significant smoking history** * **Haemothorax**

Question 76

If a patient has persistent pneumothoraces, how do you treat them? [1]

Answer 76

If a patient has a persistent air leak or insufficient lung reexpansion despite chest drain insertion, or the patient has recurrent pneumothoraces, then **video-assisted thoracoscopic surgery (VATS)** should be considered to allow for **mechanical/chemical pleurodesis +/- bullectomy.**

Question 77

How long should you get a primary spontaneous pneumothorax patient to come to outpatients after letting them go? [1] How long should you get a secondary spontaneous pneumothorax patient to come to outpatients after letting them go? [1]

Answer 77

**Primary spontaneous pneumothorax** that is managed conservatively should be reviewed: - **every 2-4 days as an outpatient** Secondary spontaneous pneumothorax: - **follow-up in the outpatients department in 2-4 weeks**