Respiratory Flashcards
What is pneumonia?
How does it present and what are common examination findings?
Pneumonia is a respiratory tract infection of the lung tissue, causing inflammation in the alveolar space.
Presenting symptoms:
Cough
Sputum production
Shortness of breath
Fever
Feeling generally unwell
Haemoptysis (coughing up blood)
Pleuritic chest pain (sharp chest pain, worse on inspiration)
Delirium (acute confusion)
Characteristic chest signs of pneumonia include:
Bronchial breath sounds (harsh inspiratory and expiratory breath sounds) due to consolidation around the airways
Focal coarse crackles caused by air passing through sputum in the airways
Dullness to percussion due to lung tissue filled with sputum or collapsed
What is the CURB-65 score?
The NICE guidelines on pneumonia (updated 2022) recommend using the CRB-65 scoring system out of hospital and CURB-65 in hospital. They suggest considering hospital assessment when the CRB-65 score is more than 0.
C – Confusion (new disorientation in person, place or time)
U – Urea > 7 mmol/L
R – Respiratory rate ≥ 30
B – Blood pressure < 90 systolic or ≤ 60 diastolic.]
65 – Age ≥ 65
The CURB-65 score predicts mortality. NICE state 0/1 is low risk (under 3%), 2 is intermediate risk (3-15%), and 3-5 is high risk (above 15%):
Score 0/1: Consider treatment at home
Score ≥ 2: Consider hospital admission
Score ≥ 3: Consider intensive care
What causes pneumonia?
What is atypical pneumonia?
The top causes of typical bacterial pneumonia are:
Streptococcus pneumoniae (most common)
Haemophilus influenzae
Atypical pneumonia is caused by organisms that cannot be cultured in the normal way or detected using a gram stain. Treatment with penicillin is ineffective. They are treated with macrolides (e.g., clarithromycin), fluoroquinolones (e.g., levofloxacin) and tetracyclines (e.g., doxycycline).
What is asthma?
Asthma is a chronic inflammatory airway disease leading to variable airway obstruction. The smooth muscle in the airways is hypersensitive and responds to stimuli by constricting and causing airflow obstruction. This bronchoconstriction is reversible with bronchodilators, such as inhaled salbutamol.
Asthma is one of several atopic conditions, including eczema, hay fever and food allergies. Patients with one of these conditions are more likely to have others. These conditions characteristically run in families.
Asthma typically presents in childhood. However, it can present at any age. Adult-onset asthma refers to asthma presenting in adulthood. Occupational asthma refers to asthma caused by environmental triggers in the workplace.
The severity of symptoms of asthma varies enormously between individuals. Acute asthma exacerbations involve rapidly worsening symptoms and can quickly become life-threatening.
How does asthma present and what are typical triggers?
Symptoms are episodic, meaning there are periods where the symptoms are worse and better. There is diurnal variability, meaning the symptoms fluctuate at different times of the day, typically worse at night.
Typical symptoms are:
Shortness of breath
Chest tightness
Dry cough
Wheeze
Symptoms should improve with bronchodilators. No response to bronchodilators reduces the likelihood of asthma.
Patients may have a history of other atopic conditions, such as eczema, hayfever and food allergies. They often have a family history of asthma or atopy.
Examination is generally normal when the patient is well. A key finding with asthma is a widespread “polyphonic” expiratory wheeze.
Certain environmental triggers can exacerbate the symptoms of asthma. These vary between individuals:
Infection
Night-time or early morning
Exercise
Animals
Cold, damp or dusty air
Strong emotions
What are investigations done for asthma?
Spirometry is the test used to establish objective measures of lung function. It involves different breathing exercises into a machine that measures volumes of air and flow rates and produces a report. A FEV1:FVC ratio of less than 70% suggests obstructive pathology (e.g., asthma or COPD).
Reversibility testing involves giving a bronchodilator (e.g., salbutamol) before repeating the spirometry to see if this impacts the results. NICE says a greater than 12% increase in FEV1 on reversibility testing supports a diagnosis of asthma.
Fractional exhaled nitric oxide (FeNO) measures the concentration of nitric oxide exhaled by the patient. Nitric oxide is a marker of airway inflammation. The test involves a steady exhale for around 10 seconds into a device that measures FeNO. NICE say a level above 40 ppb is a positive test result, supporting a diagnosis. Smoking can lower the FeNO, making the results unreliable.
Peak flow variability is measured by keeping a peak flow diary with readings at least twice daily over 2 to 4 weeks. NICE says a peak flow variability of more than 20% is a positive test result, supporting a diagnosis.
Direct bronchial challenge testing is the opposite of reversibility testing. Inhaled histamine or methacholine is used to stimulate bronchoconstriction, reducing the FEV1 in patients with asthma. NICE say a PC20 (provocation concentration of methacholine causing a 20% reduction in FEV1) of 8 mg/ml or less is a positive test result.
What is the long term management of asthma?
1) Short-acting beta-2 agonist inhaler (e.g. salbutamol) as required
2) Inhaled corticosteroid (low dose) taken regularly
3) Leukotriene receptor antagonist (e.g., montelukast) taken regularly
4) Long-acting beta-2 agonists (e.g., salmeterol) taken regularly
5) Consider changing to a maintenance and reliever therapy (MART) regime
6) Increase the inhaled corticosteroid to a moderate dose
7) Consider high-dose inhaled corticosteroid or additional drugs (e.g., LAMA or theophylline)
8) Specialist management (e.g., oral corticosteroids)
What is acute exacerbation of asthma?
acute exacerbation of asthma involves a rapid deterioration in symptoms. Any typical asthma triggers, such as infection, exercise or cold weather, could set off an acute exacerbation.
Presenting features of an acute exacerbation are:
Progressively shortness of breath
Use of accessory muscles
Raised respiratory rate (tachypnoea)
Symmetrical expiratory wheeze on auscultation
The chest can sound “tight” on auscultation, with reduced air entry throughout
On arterial blood gas analysis, patients initially have respiratory alkalosis, as a raised respiratory rate (tachypnoea) causes a drop in CO2. A normal pCO2 or low pO2 (hypoxia) is a concerning sign, as it means they are getting tired, indicating life-threatening asthma. Respiratory acidosis due to high pCO2 is a very bad sign.
Grading Acute Asthma
Moderate exacerbation features:
Peak flow 50 – 75% best or predicted
Severe exacerbation features:
Peak flow 33-50% best or predicted
Respiratory rate above 25
Heart rate above 110
Unable to complete sentences
Life-threatening exacerbation features:
Peak flow less than 33%
Oxygen saturations less than 92%
PaO2 less than 8 kPa
Becoming tired
Confusion or agitation
No wheeze or silent chest
Haemodynamic instability (shock)
What is the management for patients with acute exacerbations of asthma?
Patients with an acute exacerbation of asthma can deteriorate quickly. Acute asthma is potentially life-threatening. Treatment should be aggressive and they should be escalated early to seniors and intensive care. Treatment decisions, particularly intravenous aminophylline, salbutamol and magnesium, should involve experienced seniors.
Mild exacerbations may be treated with:
Inhaled beta-2 agonists (e.g., salbutamol) via a spacer
Quadrupled dose of their inhaled corticosteroid (for up to 2 weeks)
Oral steroids (prednisolone) if the higher ICS is inadequate
Antibiotics only if there is convincing evidence of bacterial infection
Follow-up within 48 hours
Moderate exacerbations may additionally be treated with:
Consider hospital admission
Nebulised beta-2 agonists (e.g., salbutamol)
Steroids (e.g., oral prednisolone or IV hydrocortisone)
Severe exacerbations may additionally be treated with:
Hospital admission
Oxygen to maintain sats 94-98%
Nebulised ipratropium bromide
IV magnesium sulphate
IV salbutamol
IV aminophylline
how are obstructive and restrictive lung diseases diagnosed?
Obstructive lung disease is diagnosed when the FEV1 is less than 70% of the FVC, meaning a FEV1:FVC ratio of less than 70%. This suggests that obstruction is slowing the air passage out of the lungs. The person may have a relatively good lung volume, but air can only move slowly in and out of the lungs due to obstruction.
In asthma, the obstruction is a narrowed airway due to bronchoconstriction. In COPD, there is chronic airway and lung damage, causing obstruction. You can test the reversibility of this obstruction by giving a bronchodilator (e.g., salbutamol). The obstructive picture is typically reversible in asthma but less so in COPD.
In restrictive lung disease:
FEV1 and FVC are equally reduced
FEV1:FVC ratio greater than 70%
Restrictive lung disease limits the ability of the lungs to expand and fill with air. The lungs are restricted from effectively expanding. This is different from obstructive lung disease, where there is obstructed airflow.
Restriction of lung expansion leads to inadequate ventilation of the alveoli and insufficient blood oxygenation.
The FEV1:FVC ratio is normal or raised in restrictive lung disease without obstructive pathology affecting airflow through the airways. The FVC is reduced due to the restriction of lung expansion and capacity.
Restrictive lung disease includes conditions that limit how well the chest wall and lungs can expand, for example:
Interstitial lung disease, such as idiopathic pulmonary fibrosis
Sarcoidosis
Obesity
Motor neurone disease
Scoliosis
What is COPD and how does it present?
Chronic obstructive pulmonary disease (COPD) involves a long-term, progressive condition involving airway obstruction, chronic bronchitis and emphysema. It is almost always the result of smoking and is largely preventable. While it is not reversible, it is treatable.
Damage to the lung tissues obstructs the flow of air through the airways. Chronic bronchitis refers to long-term symptoms of a cough and sputum production due to inflammation in the bronchi. Emphysema involves damage and dilatation of the alveolar sacs and alveoli, decreasing the surface area for gas exchange.
Unlike asthma, airway obstruction is minimally reversible with bronchodilators, such as salbutamol. Patients are susceptible to exacerbations, during which their lung function worsens. Exacerbations triggered by infection are called infective exacerbations of COPD.
Presentation
A typical presentation of COPD is a long-term smoker with persistent symptoms of:
Shortness of breath
Cough
Sputum production
Wheeze
Recurrent respiratory infections, particularly in winter
What is the long term management of COPD?
Continuing smoking will progressively worsen lung function and prognosis. Smoking cessation services are available.
Patients should have the pneumococcal and annual flu vaccine.
Pulmonary rehabilitation involves a multidisciplinary approach to help improve function and quality of life, including physical training and education.
Initial medical treatment recommended by the NICE guidelines (updated 2019) involves:
Short-acting beta-2 agonists (e.g., salbutamol)
Short-acting muscarinic antagonists (e.g., ipratropium bromide)
The second step, when symptoms or exacerbations are still a problem, is determined by whether there are asthmatic or steroid-responsive features, measured by:
Previous diagnosis of asthma or atopy
Variation in FEV1 of more than 400mls
Diurnal variability in peak flow of more than 20%
Raised blood eosinophil count
Where there are no asthmatic or steroid-responsive features, treatment is a combination of:
Long-acting beta agonist (LABA)
Long-acting muscarinic antagonist (LAMA)
Anoro Ellipta, Ultibro Breezhaler and DuaKlir Genuair are examples of LABA and LAMA combination inhalers.
Where there are asthmatic or steroid-responsive features, treatment is a combination of:
Long-acting beta agonist (LABA)
Inhaled corticosteroid (ICS)
Fostair, Symbicort and Seretide are examples of LABA and ICS combination inhalers.
The final inhaler step is a combination of a LABA, LAMA and ICS. Trimbow, Trelegy Ellipta and Trixeo Aerosphere are examples of LABA, LAMA and ICS combination inhalers.
In more severe cases, additional options (guided by a specialist) are:
Nebulisers (e.g., salbutamol or ipratropium)
Oral theophylline
Oral mucolytic therapy to break down sputum (e.g., carbocisteine)
Prophylactic antibiotics (e.g., azithromycin)
Oral corticosteroids (e.g., prednisolone)
Oral phosphodiesterase-4 inhibitors (e.g., roflumilast)
Long-term oxygen therapy at home
Lung volume reduction surgery (removing damaged lung tissue to improve the function of healthier tissue)
Palliative care (opiates and other drugs may be used to help breathlessness)
Patients taking azithromycin need ECG and liver function monitoring before and during treatment.
Long-term oxygen therapy (LTOT) is used for severe COPD with chronic hypoxia (sats < 92%), polycythaemia, cyanosis or cor pulmonale. Smoking is a contraindication due to the fire risk.
What is the management of an acute exacerbation of COPD?
First-line medical treatment of an acute exacerbation of COPD involves:
Regular inhalers or nebulisers (e.g., salbutamol and ipratropium)
Steroids (e.g., prednisolone 30 mg once daily for 5 days)
Antibiotics if there is evidence of infection
Respiratory physiotherapy can be used to help clear sputum.
Additional options in severe cases include:
IV aminophylline
Non-invasive ventilation (NIV)
Intubation and ventilation with admission to intensive care
Doxapram may be used as a respiratory stimulant where NIV or intubation is not appropriate.
What is bronchiectasis and what are the causes?
Bronchiectasis involves permanent dilation of the bronchi, the large airways that transport air to the lungs. Sputum collects and organisms grow in the wide tubes, resulting in a chronic cough, continuous sputum production and recurrent infections.
Bronchiectasis results from damage to the airways. Potential causes of this damage include:
Idiopathic (no apparent cause)
Pneumonia
Whooping cough (pertussis)
Tuberculosis
Alpha-1-antitrypsin deficiency
Connective tissue disorders (e.g., rheumatoid arthritis)
Cystic fibrosis
Yellow nail syndrome
What are symptoms and signs of bronchiectasis?
What investigations would you do?
Key presenting symptoms are:
Shortness of breath
Chronic productive cough
Recurrent chest infections
Weight loss
Signs of bronchiectasis on examination include:
Sputum pot by the bedside
Oxygen therapy (if needed)
Weight loss (cachexia)
Finger clubbing
Signs of cor pulmonale (e.g., raised JVP and peripheral oedema)
Scattered crackles throughout the chest that change or clear with coughing
Scattered wheezes and squeaks
Sputum culture is used to identify colonising and infective organisms. The most common infective organisms are:
Haemophilus influenza
Pseudomonas aeruginosa
Chest x-ray findings include:
Tram-track opacities (parallel markings of a side-view of the dilated airway)
Ring shadows (dilated airways seen end-on)
High-resolution CT (HRCT) is the test of choice for establishing the diagnosis.
