Respiratory Flashcards
Name causes of restrictive lung disease
Pulmonary fibrosis
Asbestosis
Sarcoidosis
Acute respiratory distress syndrome
Infant respiratory distress syndrome
Kyphoscoliosis e.g. ankylosing spondylitis
Neuromuscular disorders
Severe obesity
Name causes of obstructive lung disease
Asthma
COPD
Bronchiectasis
Bronchiolitis obliterans
What spirometry results would you expect in obstructive lung disease?
FEV1 - significantly reduced
FVC - reduced or normal
FEV1% (FEV1/FVC) - reduced
What spirometry results would you expect in restrictive lung disease?
FEV1 - reduced
FVC - significantly reduced
FEV1% (FEV1/FVC) - normal or increased
What diagnostic testing is done in asthma?
Patients >= 17 years:
* Assess occupational asthma if symptoms are better on days away from work/during holidays.
* All patients to have spirometry with a bronchodilator reversibility (BDR) test
* All patients should have a FeNO test
Children 5-16 years:
* All patients to have spirometry with a BDR test
* FeNO test should be requested if there is normal spirometry or obstructive spirometry with a negative bronchodilator reversibility (BDR) test
What should be done for a pregnant woman who is smoking?
- Smoking clinic referral
- Nicotine replacement therapy
Bupropion and varenicline are contraindicated
When should a patient with COPD be offered long-term oxygen therapy according to BTS guidelines.
Two arterial blood gases measurements with pO2 < 7.3 kPa (at least 3 weeks apart)
What are the most common causes of superior vena cava syndrome?
Lung cancer - more common
Non-Hodgkin’s lymphoma
What would a patient with acute moderate asthma present with?
PEFR 50-75% best or predicted
Speech normal
RR < 25 / min
Pulse < 110 bpm
What would a patient with acute severe asthma present with?
PEFR 33 - 50% best or predicted
Can’t complete sentences
RR > 25/min
Pulse > 110 bpm
What would a patient with acute life-threatening asthma present with?
PEFR < 33% best or predicted
Oxygen sats < 92%
Silent chest, cyanosis or feeble respiratory effort
Bradycardia, dysrhythmia or hypotension
Exhaustion, confusion or coma
*a normal pCO2 also indicates exhaustion (too tired to breathe so CO2 creeps up)
What is the typical features of a patient with aspergilloma?
Often past history of tuberculosis.
Haemoptysis may be severe
Chest x-ray shows rounded opacity
A 71-year-old woman presents with dyspnoea and haemoptysis for the past two weeks. Clinical examination reveals a loud first heart sound, a diastolic murmur and new-onset atrial fibrillation.
What is the likely cause of her symptoms?
Mitral stenosis. It can present with:
* Dyspnoea
* Haemoptysis - rupture of the bronchial veins caused by raised left atrial pressure
* Atrial fibrillation
* Malar flush on cheeks
* Mid-diastolic murmur
What are pleural plaques?
Areas of benign fibrous thickening on the pleura (the lining of the lungs) and are often associated with exposure to asbestos. They are usually asymptomatic and do not typically affect lung function.
They usually develop 2-4 decades after exposure. They are benign and do not require regular monitoring.
CXR shows bilateral pleural thickening.
What general COPD management should be offered to patients?
- Smoking cessation advice: including offering nicotine replacement therapy, varenicline or bupropion
- Annual influenza vaccination
- One-off pneumococcal vaccination
- Pulmonary rehabilitation
In which lung zones would you see fibrosis for TB patients?
Upper zone fibrosis
TB is an aerobic organism. Therefore, it needs plenty of oxygen to survive. Due to V/Q mismatch, there is more ventilation at the top of the lungs, especially near the apex. So naturally, TB has better survival in those areas, leading to upper zone fibrosis
What is the management of primary pneumothorax?
- If the rim of air is < 2cm and the patient is not short of breath then discharge should be considered
- Otherwise, aspiration should be attempted
- If this fails (defined as > 2 cm or still short of breath) then a chest drain should be inserted
What is the management of secondary pneumothorax?
- If the patient is > 50 years old and the rim of air is > 2cm and/or the patient is short of breath then a chest drain should be inserted.
- Otherwise aspiration should be attempted if the rim of air is between 1-2cm. If aspiration fails (i.e. pneumothorax is still greater then 1cm) a chest drain should be inserted. All patients should be admitted for at least 24 hours
- If the pneumothorax is less the 1cm then the BTS guidelines suggest giving oxygen and admitting for 24 hours
What are the different classifications of pneumothorax?
Spontaenous - primary or secondary
Traumatic
Iatrogenic
Name causes of transudative pleural effusion
Heart failure
Hypoalbuminaemia (e.g. liver disease, nephrotic syndrome)
Meigs syndrome
Name causes of exudative plerual effusion
Infection (e.g. pneumonia, tuberculosis)
Lung cancer or metastases
Connective tissue diseases (e.g. rheumatoid arthritis, SLE)
What is the difference between a transudate and an exudate?
Transudate protein level <30 g/L
Exudate protein level >30 g/L
What does Light’s criteria define?
An exudate is likely if at least one of the following criteria are met:
* pleural fluid protein : serum protein >0.5
* pleural fluid LDH : serum LDH >0.6
* pleural fluid LDH more than two-thirds the upper limits of normal serum LDH
What is the most common cause of occupational asthma?
Isocyanates - from spray paiting and foam moulding with adhesives
What is the management of occupational asthma?
Serial measurements of peak expiratory flow are recommended at work and away from work.
Referral should be made to a respiratory specialist for patients with suspected occupational asthma.
What would a patient with acute near-fatal asthma present with?
Raised pC02
Requiring mechanical ventilation with raised inflation pressures
*This is a 4th category after life-threatening
What are the common features of sarcoidosis?
Acute: erythema nodosum, bilateral hilar lymphadenopathy, swinging fever, polyarthralgia
Insidious: dyspnoea, non-productive cough, malaise, weight loss
Skin: lupus pernio
Hypercalcaemia: macrophages inside the granulomas cause an increased conversion of vitamin D to its active form (1,25-dihydroxycholecalciferol)
What is the mechanism of montelukast?
Leukotriene receptor antagonist
Leukotrienes are produced in response to allergens. They cause narrowing and swelling of airways in the lungs, leading to asthma symptoms
Name causes of acute respiratory distress syndrome
- Infection: sepsis, pneumonia
- Massive blood transfusion
- Trauma
- Smoke inhalation
- Acute pancreatitis
- Covid-19
- Cardio-pulmonary bypass
Which lung zones are commonly affected in aspiration pneumonia?
Right middle and lower zones due to the larger calibre and more vertical orientation of the right main bronchus.
What are the severity categories of COPD?
Stage 1 - Mild - symptoms should be present to diagnose COPD in these patients: FEV1 >80%
Stage 2 - Moderate: FEV1 50-79%
Stage 3 - Severe: FEV1 30-49%
Stage 4 - Very severe: FEV1 <30%
*Post-bronchodilator FEV1/FVC should be <0.7 for all categories
What arterial blood gas do you usually see in a stable longterm COPD patient?
Chronic respiratory acidosis (due to COPD) with a compensatory metabolic alkalosis (the elevated bicarbonate is the main clue to the chronic nature of the respiratory acidosis)
When do you offer longterm oxygen therapy (LTOT) to COPD patients?
If pO2 of < 7.3 kPa or those with a pO2 of 7.3 - 8 kPa and one of the following:
* secondary polycythaemia
* peripheral oedema
* pulmonary hypertension
What are common features of alpha-1 antitrypsin deficiency?
Lungs: panacinar emphysema, most marked in lower lobes
Liver: cirrhosis and hepatocellular carcinoma in adults, cholestasis in children
Investigations: Low A1AT concentrations + obstructive picture on spirometry
What is the difference between centriacinar and panacinar emphysema?
Centrilobular (mostly upper lung zones) - seen in smoking and pneumoconiosis
Panacinar (mostly lower lung zones) - seen in alpha-1 antitrypsin deficiency
What pulmonary issue is commonly associated with low glucose on pleural fluid?
Empyema (with associated high protein - exudate)
What is the management of an empyema?
Prompt drainage with antibiotic therapy
What is the investigation of choice in suspected idiopathic pulmonary fibrosis?
High resolution CT
What does the total gas transfer (TLCO) measure?
Overall measure of gas transfer for the lungs from the alveoli into the capillaries and reflects how much oxygen is taken up into the red cells
Which conditions would have a raised total gas transfer (TLCO)?
- Asthma
- Pulmonary haemorrhage (e.g. granulomatosis with polyangiitis, Goodpasture’s)
- Left-to-right cardiac shunts
- Polycythaemia
- Hyperkinetic states
- Male gender, exercise
Which conditions would have a low total gas transfer (TLCO)?
- Pulmonary fibrosis
- Pneumonia
- Pulmonary emboli
- Pulmonary oedema
- Emphysema
- Anaemia
- Low cardiac output
What is the transfer coefficient (KCO)?
TLCO divided by the alveolar volume, which makes it a measure of how efficient gas exchange is in relation to the alveolar-capillary surface to volume ratio
What is the mechanism of varenicline, what side effects does it cause and what are its contraindications?
Nicotinic receptor partial agonist
Nausea is the most common adverse effect. Other common problems include headache, insomnia, abnormal dreams
Contraindicated in pregnancy and breast feeding
What is the mechanism of bupropion, what side effects does it cause and what are its contraindications?
A norepinephrine and dopamine reuptake inhibitor, and nicotinic antagonist
Small risk of seizures (1 in 1,000)
Contraindicated in epilepsy, pregnancy and breast feeding. Having an eating disorder is a relative contraindication
What is the most common organism isolated from patients with bronchiectasis?
Haemophilus influenzae
What is the criteria for discharge following an acute asthma attack?
- Been stable on their discharge medication (i.e. no nebulisers or oxygen) for 12–24 hours
- Inhaler technique checked and recorded
- PEF >75% of best or predicted
What is the golden S sign on CXR and CT?
Caused by collapse of lung around a central mass (generally right upper lobe), commonly seen in lung cancers
What is the recommended amount of time to wait between each puff of an inhaler?
30 seconds
What should you do to patients with acute life-threatening asthma that do not respond to treatment?
Refer to ICU to consider for potential intubation and ventilation