Respiratory: Pulmonary Fibrosis, Bronchiectasis & Pleural Effusion Flashcards
What is a pleural effusion?
A pleural effusion is a collection of fluid in the pleural space.
What are the 2 categories of pleural effusion?
1) Exudative
2) Transudative
What defines an exudative pleural effusion?
HIGH protein count (>35g/L)
What defines a transudative pleural effusion?
LOWER protein count (<25g/L)
What criteria is used for establishing an exudative effusion?
Light’s criteria
What does Light’s criteria for establishing an exudative effusion take into account?
1) Fluid protein/serum protein –> >0.5
2) Fluid LDH/serum LDH –> >0.6
3) Pleural fluid LDH greater than 2/3 of the normal upper limit of the serum LDH
When would Light’s criteria be used
If the pleural fluid protein is between 25 and 35 g/L
What is the pathophysiology behind an exudative pleural effusion?
Inflammation –> results in protein leaking out of the tissues into the pleural space due to increased pleural and capillary permeability
What are the most common causes of exudative pleural effusions?
1) Infection – pneumonia, tuberculosis
2) Malignancy – bronchial carcinoma, mesothelioma, lung metastases
3) Rheumatoid arthritis (less common)
What is the pathophysiology behind transudative pleural effusions?
1) Disruption in hydrostatic pressure → increase in pulmonary hydrostatic pressure forces fluid out of pulmonary capillaries into pleural space
2) Disruption in oncotic pressure → impaired reabsorption of fluid from pleural space into pulmonary capillaries
What are the most common causes of transudative pleural effusions?
1) Congestive cardiac failure (most common)
2) Liver failure (most common)
3) Hypoalbuminaemia
4) Hypothyroidism
5) Meig’s syndrome
How does liver failure cause transudative pleurral effusion?
Pleural effusion is caused by high pressure in the portal vein (portal hypertension).
How does hypoalbuminemia cause transudative pleural effusion?
Hypoalbuminemia can cause a decrease in oncotic pressure causing extravasation of fluid into the interstitial space
What type of pleural effusion does malignancy cause?
Exudative
What type of pleural effusion does infection cause?
Exudative
What type of pleural effusion does liver failure cause?
Transudative
Give 3 other types of pleural effusion
1) Haemothorax –> blood in the pleural space
2) Empyema –> pus
3) Chylothorax –> chyle
What causes a chylothorax?
Chyle in the pleural space due to disruption of the thoracic duct (due to a neoplasm, trauma or infection/inflammation)
What is Meig’s syndrome? What is the triad of features?
1) Benign ovarian tumour (typically a fibroma)
2) Pleural effusion
3) Ascites
Management of Meig’s syndrome
The pleural effusion and ascites resolve with the removal of the tumour.
Would nephrotic syndrome cause a transudative or exudative pleural effusion?
Transudative
Would hypoalbuminaemia cause a transudative or exudative pleural effusion?
Transudative
Disruption of which structure leads to a chylothorax?
Thoracic duct
Typical symptoms of a pleural effusion?
Small and moderate pleural effusions are commonly asymptomatic. As the pleural effusion increases in size, symptoms begin to develop.
- Shortness of breath (typical presenting symptom)
- Cough
- Pleuritic chest pain
Typical examination findings in pleural effusion?
- ‘Stony dull’ percussion over effusion
- Reduced breath sounds
- Tracheal deviation AWAY from the effusion in very large effusions
Important areas to cover in a pleural effusion history?
- Symptoms suggestive of LUNG CANCER: haemoptysis, weight loss
- Symptoms suggestive of HEART FAILURE: orthopnoea, paroxysmal nocturnal dyspnoea, leg swelling
- Symptoms suggestive of INFECTION: productive cough, fever
- Social history: SMOKING history (lung cancer risk), ASBESTOS exposure (mesothelioma)
What respiratory condition can be associated with rheumatoid arthritis?
Pleural effusion
Differentials for pleural effusion?
Breathlessness, cough and pleuritic chest pain:
- Infection: such as pneumonia or tuberculosis
- Malignancy without effusion
- Pulmonary embolism
- Pneumothorax
Are transudative or exudative pleural effusions more likely to be bilateral?
Transudative
Are transudative or exudative pleural effusions more likely to be unilateral?
Exudative
1st line investigation in pleural effusion?
CXR
Bedside investigations in pleural effusion?
- ECG –> look for cardiac cause, or signs of right heart strain (PE)
- Urine dip –> assess for proteinuria (nephrotic syndrome)
Why would a urine dip be indicated in pleural effusion?
Assess for proteinuria which may indicate nephrotic syndrome
Potential blood tests in a pleural effusion:
- FBC → may show raised WCC (infection)
- U&Es → may show raised creatinine (renal impairment)
- LFTs & coagulation profile → may show low albumin and raised ALT/AST (cirrhosis)
- CRP → infection
- Blood cultures → infection
- ABG → if oxygenation affected
- D-dimer → if PE suspected
- Amylase → if pancreatitis suspected
- TFTs → if hyperthyroidism suspected
What are some potential CXR findings in a pleural effusion?
1) Blunting of the costophrenic angle
2) Fluid in the lung fissures
3) Larger effusions will have a meniscus (a curving upwards where it meets the chest wall and mediastinum)
4) Tracheal and mediastinal deviation away from the effusion in very large effusions
In smaller pleural effusions, which imaging investigations may be better?
US or CT
Management of a pleural effusion?
If unilateral is thought to be exudative –> pleural fluid analysis (take sample by aspiration or chest drain –> protein count, LDH, pH etc)
If small –> conservative
If bigger:
a) Pleural aspiration
b) Chest drain
Then treat underlying cause:
- Diuretics in HF
- Abx in infection
Are pleural aspirations routinely carried out for bilateral effusions with features suggestive of a transudate?
No
What is pleural aspiration?
Involves sticking a needle through the chest wall into the effusion and aspirating the fluid.
Aspiration can temporarily relieve the pressure, but the effusion may recur, and further drainage may be required.
Benefit of chest drain over pleural aspiration in pleural effusion?
Chest drain can be used to drain the effusion and prevent it from recurring.
What should be analysed about the pleural fluid in a pleural effusion?
- Protein
- LDH
- Appearance (purulent, bloody)
- pH (if not purulent)
- Glucose
What can bloody pleural fluid indicate?
infection, bloody fluid may suggest malignancy, pulmonary embolism or trauma.
What can a pleural fluid pH < 7.3 indicate?
Malignancy, pleural infection, rheumatoid arthritis, tuberculosis and oesophageal rupture
If the pleural effusion reaccumulates, what can be considered?
- Long term indwelling chest drain
- Pleurodesis (by chest drain or medical thoracoscopy)
Complications of a pleural effusion?
- Respiratory compromise.
- In parapneumonic effusions, complications may include empyema and sepsi
- Pneumothoraces (related to pleural procedures)
Pleural aspiration results in an empyema?
-pus
- low pH
- low glucose
- high LDH
management of an empyema?
Chest drain & Abx
Thoracentesis is indicated in all patients except who?
Required in all patients except those with clear evidence of HF (raised JVP, pitting ankle oedema, signs on CXR)
What is interstitial lung disease (ILD)?
An umbrella term for a broad spectrum of conditions affecting the lung interstitium, leading to INFLAMMATION and FIBROSIS.
What is the lung interstitium?
the space between an alveolus and its surrounding capillaries.
What is fibrosis in the lung?
Fibrosis involves the replacement of elastic and functional lung tissue with non-functional scar tissue.
This is irreversible.
What is the most important ILD to remember?
Idiopathic pulmonary fibrosis
Key presenting features of pulmonary fibrosis?
- Shortness of breath on exertion (progressive)
- Dry cough
- Fatigue
Examination findings:
- Bibasal fine end-inspiratory crackles
- Finger clubbing
Describe auscultation sounds in pulmonary fibrosis
Bibasal fine end-inspiratory crackles
Risk factors for ILD?
- Male sex
- Cigarette smoking
- Regular dust exposure (could be occupational)
Important aspects to cover in ILD history?
- Drug history –> Can be caused by some medications, inhaled illicit substances
- Smoking history
- Occupation
- Social history –> mould, pets, hobbies (e.g. bird-keeping)
What are some susceptible occupations for ILD?
1) farmers (hay dust and Aspergillus mould)
2) bakers (flour dust and additive enzymes)
3) plumbers/construction worker
How is ILD/PF diagnosed?
1) Clinical features
2) High-resolution CT scan (HRCT) of the thorax (showing a typical “ground glass” appearance)
3) Spirometry
Spirometry results in ILD?
1) FEV1 and FVC are equally reduced
2) FEV1:FVC ratio greater than 70%
Managmement of ILD?
Generally, there is a poor prognosis and limited management options in interstitial lung disease, and treatment is primarily supportive. Options include:
- Remove or treat the underlying cause
- Home oxygen where there is hypoxia
- Stop smoking
- Physiotherapy and pulmonary rehabilitation
- Pneumococcal and flu vaccine
- Advanced care planning and palliative care where appropriate
- Lung transplant is an option, but the risks and benefits need careful consideration
What is Idiopathic pulmonary fibrosis?
features progressive pulmonary fibrosis with no apparent cause
Presentation of pulmonary fibrosis?
- Insidious onset of SOB
- Dry cough
> 3 months
Prognosis of pulmonary fibrosis?
The prognosis is poor, with a 2-5 years life expectancy from diagnosis.
What 2 medications are licensed that can slow the progression of pulmonary fibrosis
1) Pirfenidone –> reduces fibrosis and inflammation
2) Nintedanib –> reduces fibrosis and inflammation by inhibiting tyrosine kinase
Give some causes of drug induced pulmonary fibrosis
1) Amiodarone
2) Nitrofurantoin
3) Methotrexate
What conditions can pulmonary fibrosis occur 2ary to?
- Alpha-1 antitrypsin deficiency
- Rheumatoid arthritis
- Systemic lupus erythematosus (SLE)
- Systemic sclerosis
- Sarcoidosis
What is bronchiectasis?
A chronic respiratory disease characterised by permanent bronchial dilation, due to irreversible damage to the bronchial wall.
Sputum collects and organisms grow in the wide tubes, resulting in a chronic cough, continuous sputum production and recurrent infections.
What are the bronchi?
the large airways that transport air to the lungs
Causes of bronchiectasis?
Damage to the airways:
- Idiopathic (no apparent cause - approx 40%)
Post-infectious:
- Pneumonia
- Plmonary TB
- Allergic bronchopulmonary aspergillosis (ABPA)
- Recurrent childhood LRIs e.g. whooping cough (pertussis), influenza
Pulmonary disease:
- Asthma
- COPD
Congenital:
- CF
- Alpha-1-antitrypsin deficiency (also causes emphysema)
-Connective tissue disorders:
- Rheumatoid arthritis
- SLE
- Sarcoidosis
Yellow nail syndrome
What triad is seen in yellow nail syndrome?
1) yellow fingernails
2) bronchiectasis
3) lympoedema
Patients are stable and have good clinical signs, making it a good choice for OSCEs.
Prognosis of bronchiectasis?
Patients with mild bronchiectasis often have normal life expectancies. The mortality risk increases in patients with more frequent exacerbations and worse lung function.
Risk factors for bronchiectasis?
Age (>70 years)
Female gender
Smoking history
Are men or women more prone to bronchiectasis?
Women
Key presenting symptoms in bronchiectasis?
- Shortness of breath on exertion (may progress to resting)
- Chronic productive cough
- Recurrent chest infections
- Weight loss
- Fatigue
- Rhinosinusitis symptoms e.g. nasal discharge
Is the cough in bronchiectasis dry or productive?
Productive
Is the cough in pulmonary fibrosis dry or productive?
Dry
Other important areas to cover in the history in bronchiectasis?
- History of childhood LRTIs –> you may forget to ask this if the patient is elderly
- Family history –> ask about congenital conditions (such as cystic fibrosis) and autoimmune conditions (such as rheumatoid arthritis)
- Smoking history: quantify in pack-years
Examination findings in bronchiectasis?
- Clubbing
- Coarse creptiations
- Rhonchi
- High pitched inspiratory squeaks and pops
- Sputum pot by bed
- Oxygen therapy (if needed)
- Cachexia
- Signs of cor pulmonale e.g. raised JVP, peripheral oedema
What are rhonchi?
Low-pitched noises, which sound like snoring –> caused by the movement of secretions in the large airways
What are the 2 most common infective organisms in bronchiectasis?
1) Haemophilus influenza
2) Pseudomonas aeruginosa
Investigations in bronchiectasis?
1) Sputum culture
2) CXR
3) High-resolution CT (HRCT)
4) Lung function tests
5) O2 sats
What is the test of choice for establishing a bronchiectasis diagnosis?
High-resolution CT (HRCT)
What do lung function tests typically show in bronchiectasis?
typically show an obstructive pattern (FEV1/FVC ratio < 70%), but may be normal
General management of bronchiectasis?
Vaccines (e.g., pneumococcal and influenza)
Respiratory physiotherapy to help clear sputum
Pulmonary rehabilitation
Long-term antibiotics (e.g., azithromycin) for frequent exacerbations (e.g., 3 or more per year)
Inhaled colistin for Pseudomonas aeruginosa colonisation
Long-acting bronchodilators may be considered for breathlessness
Long-term oxygen therapy in patients with reduced oxygen saturation
Surgical lung resection may be considered for specific areas of disease
Lung transplant is an option for end-stage disease
Management of infective exacerbations in bronchiectasis?
1) Sputum culture (before antibiotics)
2) Extended courses of antibiotics, usually 7–14 days
What should be done before prescribing Abx in bronchiectasis?
Sputum culture
What is the he Abx of choice for bronchiectasis exacerbations caused by Pseudomonas aeruginos?
Ciprofloxacin
Key features to remember for bronchiectasis:
1) finger clubbing
2) diagnosis by HRCT
3) Pseudomonas colonisation
4) Extended courses of 7-14 days of antibiotics for exacerbations
