Respiratory: Asthma, COPD & Lung Cancer Flashcards
Give some red flags for a respiratory history/examination
- Weight loss
- Haemoptysis
- Persistent dry cough (>3 weeks)
- Foreign travel
- Smoking history
- Sudden onset SOB
- Chest pain
- Drenching night sweats
What is the most common lung disease in the UK?
Asthma
Give the 3 mechanisms behind airway narrowing in asthma
1) Bronchial muscle contraction
2) Inflammation caused by mast cell degranulation
3) Increased mucus production
Asthma often shows a diurnal variation. What does that mean?
Symptoms worse in morning
percussion in acute asthma?
hyperresonant (air)
Inflation of lungs in acute asthma?
hyperinflation
Auscultation of lungs in acute asthma?
Bilateral decreased air entry
Wheeze
Are symptoms in asthma bilateral or unilateral?
Bilateral
What is a ‘silent chest’ in asthma a sign of?
Severe illness - life-threatening
What is the diagnostic investigation in asthma?
Spirometry
How does spirometry and PEFR differ?
Both tests measure the speed and efficiency with which air moves in and out of the lungs.
Spirometry - offers a larger set of parametric values regarding lung health than a peak flow meter does and requires a patient to perform specific breathing manoeuvres using a spirometer.
PEFR - can be performed at bedside/patient home
What spirometry result indicates asthma?
FEV1/FVC <0.7 (70%) –> obstructive airway disease
What is the FEV1/FVC ratio?
The FEV1/FVC ratio is the ratio of the forced expiratory volume in the first one second to the forced vital capacity of the lungs (i.e. indicates how much air you can forcefully exhale)
Measured by spirometry
Give some other investigations that can be used in chronic asthma?
1) Bronchodilator reversibility tests
2) FeNO (fractional exhaled nitric oxide)
3) Skin prick test - confirm atopy
What bronchodilator reversibility test result indicates asthma?
Improvement of FEV1 >12% after bronchodilator therapy is diagnostic
What is the stepwise pharmacological long-term management of asthma (NICE)
- SABA
- ICS (low dose)
- LTRA e.g. montelukast
4a) SABA + low dose ICS + LABA (can stop or continue LTRA depending on patient’s response)
5) SABA +/- LTRA, switch ICS/LABA for a MART that includes low dose ICS
6) SABA +/- LTRA + MART (medium dose ICS)
What are the aims of pharmacological management of asthma?
- No daytime symptoms
- No night-time waking due to asthma
- No asthma attacks
- No limitations on activity including exercise
- Minimal side effects from medication
Pathophysiology behind an asthma attack?
IgE type 1 hypersensitivity reaction leading to smooth muscle contraction, bronchial oedema and mucus plugging.
What medications can exacerbate asthma?
1) Acetylcholinesterase inhibitors e.g. Donepezil
2) Beta blockers e.g. bisoprolol
3) NSAIDs
Why can AChEIs exacerbate asthma?
Due to increased bronchial secretions
Give some triggers for an asthma attack
- Exposure to allergens e.g. dust, pollution, animal hair or smoke
- URT or LRTIs
- Cessation or reduction of asthma medications
- Concomitant medications e.g. beta blockers, NSAIDs
- Triggers e.g. exercise, cold air
Give some signs of an acute asthma attack
- Use of accessory muscles of respiration
- Hyperinflation of the chest
- Tachypnoea
- Tachycardia
- Diaphoresis (sweating)
Give some signs of a severe asthma attack
- Inability to speak in full sentences
- RR >25
- Peak flow 33-50% predicted
Give some signs of a life-threatening asthma attack
- PEFR <33% predicted
- O2 sats <92%
- Silent chest on auscultation
- Confusion
- Bradycardia
- Hypotension
- Cyanosis
- Exhaustion – weak or no respiratory effort
What may bradycardia in a life-threatening asthma attack indicate?
Impending respiratory attack
What does an FeNO test indicate?
Measures level of NO in breath which is a sign of inflammation in lungs
Which bloods are important in acute asthma?
- FBC – infection
- CRP – infection
- Eosinophil count
- Total IgE
- IgE to aspergillus
Which imaging is 1st line in acute asthma?
CXR
What may a CXR in acute asthma show?
usually normal (may show hyperinflation or bronchial wall thickening)
Give the stepwise pharmacological management in an acute asthma attack (ABCDE)
- Sit up and give oxygen
- Nebulised salbutamol (high dose)
- Corticosteroid (oral prednisolone or IV hydrocortisone)
- Nebulised ipratropium bromide (if needed)
Maybe:
5. IV magnesium sulphate
6. IV aminophylline
When would ipratropium bromide be given in acute asthma? What is the effect of this?
Add for patients with acute severe or **life-threatening asthma or to those with a poor initial response to b2 agonist therapy.
Combining nebulised ipratropium bromide with a nebulised b-2 agonist produces significant bronchodilation than a b-2 agonist alone.
Who should steroid therapy be administered to in patients presenting with an acute asthma attack?
ALL patients with acute asthma
What steroids should be used in acute asthma?
Oral prednisolone 40-50mg
If oral route unavailable (likely) → IV hydrocortisone
How long should oral prednisolone be continued for following an acute asthma attack?
5 days or until full recovery
When would you consider giving IV magnesium sulphate in acute asthma?
- Acute severe asthma who have not had a good response to inhaled therapy
- Life-threatening or near-fatal asthma
- Only use after consultation with senior medical staff
What would reduced air entry in acute asthma indicate?
significant airway compromise
What would absent air entry on auscultation in acute asthma indicate?
Underlying pneumothorax
What would dullness on percussion in acute asthma indicate?
- Pleural effusion
- Lobar collapse
Typical ABG results in acute asthma?
Low PaO2 and low PaCo2
What is COPD?
A triad of chronic bronchitis, emphysema and small airway fibrosis causing irreversible obstruction of air flow; bronchitis or emphysema can be the predominant condition.
Most common cause of COPD?
Smoking (95%)
Which inherited disorder can predispose to COPD?
Alpha 1 antitrypsin deficiency
How is alpha 1 antitrypsin deficiency inherited?
Autosomal dominant
How does alpha 1 antitrypsin deficiency increase risk of COPD?
Alpha 1 antitrypsin is a protein produced by the liver that protects the lungs.
Without this, the lungs are more easily damaged e.g. by dust
What other conditions can alpha 1 antitrypsin deficiency predispose to?
Liver cancer & lung cancer
COPD is usually a combination of chronic bronchitis and emphysema. What are these 2 conditions?
Chronic bronchitis - chronic inflammation of the bronchi (usually defined as a productive cough on most days for 3 months a year over 2 successive years)
Emphysema - enlargement of air spaces in the terminal bronchioles leading to inefficient gas exchange ratios and poor air outflow
What is the pathogenesis behind COPD?
Chemicals and heat trigger inflammation in bronchi and lung parenchyma
- Bronchi → persistent inflammation leads to scarring and mucus hyperplasia (bronchitis)
- Parenchyma → inflammation leads to alveolar wall loss (emphysema)
Give some triggers for COPD exacerbations
- Viral or bacterial lung infection (acute bronchitis or pneumonia)
- Smoking
- Exposed to smoke or air pollution
Give some symptoms of COPD
- Dyspnoea (may only happen at first when exercising)
- Chronic productive cough (sputum usually colourless, may become green in LRTIs)
- Recurrent LRTIs
- Fatigue
- Headache (due to CO2 retention)
- Trouble taking a deep breath
- Chest tightness
Give some symptoms of an exacerbation of COPD
- More coughing, wheezing, or SOB than usual
- Changes in colour, thickness or amount of mucus
- Feeling tired for more than 1 day
- Swelling of legs or ankles
- O2 levels lower than normal
- Severe –> cyanosis, severe SOB, chest pain, confusion
What signs are seen in a COPD exacerbation?
- Accessory muscle use & pursed lips
- Tachypnoea
- Hyperinflation
- Reduction of cricosternal distance
- Reduced chest expansion
- Hyper resonant percussion
- Decreased/quiet breath sounds
- Wheeze on auscultation (due to inflammatory airway oedema and mucous obstruction)
- Cyanosis
- Cor pulmonale (signs of RHF)
- CO2 retention flap
- Reduced conscious level
- Severe → tachycardia, tachypnoea, hypoxia, cyanosis, reduced consciousness
What is the typical spirometry finding in COPD?
FEV1/FVC <0.7
What SpO2 should you aim for in COPD patients?
88-92%
How can COPD affect the heart?
COPD can cause low oxygen levels in the blood, thereby placing additional stress on the heart.
This can lead to right ventricle hypertrophy and potentially cor pulmonale
What 2 cardiac conditions can COPD lead to?
- Right ventricle hypertrophy
- Cor pulmonale
What is cor pulonale?
Cor pulmonale is a condition that causes the RIGHT side of the heart to fail.
Long-term high blood pressure in the arteries of the lung and right ventricle of the heart can lead to cor pulmonale
Which side of the heart fails in cor pulmonale?
Right
What may an FBC show in COPD?
Raised MCV - polycythaemia
What is MCV? What does it measure?
Mean corpuscular volume –> MCV blood test measures the average size of your red blood cells.
What is polycythaemia?
Increased number of RBCs
Cause of polycythaemia in COPD?
compensatory physiologic response to hypoxia.
What may an ABG show in COPD?
Low PaO2
Raised PaCO2 (type 2 respiratory failure)
What is the purpose of a sputum sample in COPD exacerbation?
Enables targeted antibiotic therapy
What may a CXR show in COPD
- Hyperinflated chest (>6 anterior ribs)
- Bullae
- Decreased peripheral vascular markings
- Flattened hemidiaphragms
How should oxygen be delivered to COPD patients during acute exacerbations?
Use a venturi mask and titrate appropriately
Sit them upright.
Give the pharmacological management of an acute COPD exacerbation
- Oxygen
- Nebulised salbutamol
- Nebulised ipratropium bromide
- Steroids
What steroids should be used in the management of a COPD exacerbation?
Oral prednisolone (IV hydrocortisone if needed)
Give the stepwise pharmacological management of chronic COPD
- Short acting B2-agonist (SABA) OR short acting muscarinic antagonist (SAMA)
- Add LABA and LAMA
- LAMA + LABA + ICS
Example of a short acting muscarinic antagonist (SAMA)?
Ipratropium bromide
What ECG changes may be seen in COPD?
- Right axis deviation
- Prominent p waves in inferior leads
- Inverted p waves in high lateral leads (I, aVL)
- Low voltage QRS
- P pulmonale
- RBBB
Looks these up
What may the presence of tall, peaked P waves in lead II indicate?
A sign of right atrial enlargement, usually due to pulmonary hypertension
Where is the apex beat located?
5th intercostal space, mid-clavicular line
What are Curschmann spirals? What conditon are they present in?
Can be seen on histology where shed epihetlium becomes whorled mucous plugs
Asthma
What % of lung cancers are thought to be preventable?
80%
Histologically, what are the 2 types of lung cancer?
1) Small-cell lung cancer (SCLC) (20%)
2) Non-small-cell lung cancer (NSCLC) (80%)
Are small cell or non small cell lung cancers more common?
Non-small cell (80%)
What is the most common type of NSCLC?
Adenocarcinoma (40%)
What is the 2nd most common type of NSCLC?
Squamous cell carcinoma (20%)
Give 3 main types of NSCLC
1) Adenocarcinoma (40%)
2) Squamous cell carcinoma (20%)
3) Large cell carcinoma (10%)
4) Other types (around 10%)
Give some red flag symptoms for lung cancer
- Cachexia
- Pain when breathing (dyspnoea)
- Haemoptysis
- Persistent dry cough
- N&V
- Chest pain
Lung cancer can present with Horner’s syndrome. Give the location of the tumour in this instance
Apical tumour (e.g. Pancoast) –> interrupted sympathetic supply to face
Which type of cancer is responsible for paraneoplastic syndromes? Why?
SCLC –> contain neurosecretory granules that release neuroendocrine hormones.