Respiratory Flashcards
Classify asthma into early and late onset and discuss the likely presenting characteristics of each
Early onset: Usually extrinsic (allergic) Younger patients Elevated IgE Eczema and rhinitis
Late onset: May be intrinsic >30yo No history of atopy May be caused by stress cold etc
Outline common precipitants of an asthma attack. 12
Allergens Stress Emotions Cold Exercise Smoking URTI Drugs (B-blocker, NSAIDs) Work (paint sprayers) GORD Food/drink Pollution
Describe the clinical features of an acute asthma attack 5
Reduced air entry Polyphonic wheeze Hyperresonance Hyperinflated chest Tachypnoea
Severe:
High pulse and resp rate
confused
Life threatening:
Silent chest
Bradycardia
Cyanosis
Describe the blood gas abnormalities associated with severe asthma and highlight other clinical indices of severity
In mild attacks pCO2 may be low
A normal pCO2 indicates deterioration
In life threatening conditions an high pCO2, severe hypoxia and a low pH.
Predicted PEF<50% indicates severe, and <33% life-threat.
Describe how to use inhaler devices and other aids appropriately
Shake the inhaler, take a normal breath out, place the inhaler in your mouth and simultaneously breathe in and press the button to release the aerosol. Hold the breath in for 10 seconds if possible. Important not to just spray the inhaler into the mouth! With the steroid inhaler, the patient should be counselled to rinse the mouth out after use.
Describe the morphology and pathological consequences of asthma
Type 1 hypersensitivity reaction: Th2 cells activate plasma cells to produce antibodies.
These cross-link antigens and stimulate mast cells to produce inflammatory mediators.
Eosinophils also produce inflammatory mediators.
Type 4 hypersensitivity may also occur where the smooth muscle becomes hypertrophied.
Smooth muscle constricts the bronchioles (may cause a chronic thickening of bronchiole walls) and a mucus plug may also form.
Describe the principles and elements of spirometry including measurements of FEV1 and FVC and the difference between obstructive and restrictive abnormalities
FEV1 is the maximum amount of air that can be expired in 1 second.
FVC is the difference between the maximum inspiratory volume and the minimum inspiratory volume.
In obstructive lung disease eg asthma FEV1/FVC can be <0.7
In restrictive both FEV and FVC may be reduced but ratio may be normal or slight increased
Define chronic obstructive pulmonary disease (COPD).
A chronic disease state causing a reduced airflow which is not fully reversible.
It is progressive and involves an inappropriate inflammatory response in the lungs to noxious substances and gases.
Encompasses bronchitis and emphysema
Describe the typical history of a patient with COPD 5 and 4 systemic effects
SOB Wheeze Clear/white sputum Cough Frequent chest infections Systemic effects: Hypertension depression, decrease in muscle mass osteoporosis
Describe the pathology features and complications of chronic bronchitis.
Caused by inflammation of bronchioles due to cigarette smoke.
Causes an increase in goblet cells, resulting in increased cough and sputum production.
This may result in airway narrowing du to scarring and thickening of walls.
Describe the pathology features and complications of emphysema
Caused by the destruction of alveoli in the lung.
Smoke inactivates alpha-1 antitrypsin which protects lungs against the actions of proteases such as neutrophil elastase, breaking down alveolar walls.
List recognised risk factors for the condition 4
Smoking (largest)
Pollution
Alpha-1 antitrypsin deficiency
Occupation (mining)
What are the signs of COPD? 7
Use of accessory muscles to breathe Pursed lips May have barrel chest May be tachypnoeic Flapping tremor Bounding pulse Reduced chest expansion
Describe features which are consistent with a pink puffer. 2
Increased respiratory rate
Weight loss and muscle wasting
Describe features which are consistent with a blue bloater. 6
Increased lung volume Polycythemia Cyanosis Regular/reduced resp rate Hypercapnia hypoxemia
Outline the investigation of a patient with suspected COPD.
Spirometry - reduced FEV/FVC ratio. Raised haematocrit, Hb, CRP CT may show bullae Echo/ECG if suspected heart involvement Alpha - 1 antitrypsin testing if non smoker and/or young
Interpret a CXR showing features of COPD/emphysema
Bullae may be present
Hyperexpansion of lungs may present via narrow heart shape and a flat diaphragm
Describe the typical history of a patient with bronchiectasis and differentiate it from COPD.
Cough
Purulent sputum production (often worse in the morning)
Haemoptosis
Halitosis
Systemic effects: Fever, malaise, weight loss
Outline the morphology and pathological consequences of Bronchiectasis.
Bronchioles become thickened, inflammed and dilated.
Mucus transport mechanisms fail, leading to mucostasis and recurrent infections.
Squamous metaplasia and loss of cilia also occurs.
List recognised risk factors for bronchiectasis 5
Congenital Post infection (TB, pneumonia) Mechanical obstruction (bronchial carcinoma) Mucocilliary defects - CF Immunocompromised patients
What are the physical signs of bronchiectasis?
Clubbing
Halitosis
Course inspiratory crackles over affected area
Production of thick khaki coloured sputum
Patient may be febrile
Outline the investigations of a patient with suspected bronchiectasis
CXR may be clear or show bronchiole dilation
CT may show bronchiole wall thickening with cyst formation at the terminal end.
Sputum culture may show organisms responsible for infection if present.
How would one differentiate bronchiectasis from COPD?
Clubbing is common, unlike in COPD.
Sputum in COPD is not of the same quantity.
Unlike in COPD, there is no wheeze.
Describe the typical presentation of a patient with a community acquired pneumonia.
Often preceded by a viral infection.
Patient becomes more ill, develops a temperature.
Dry cough at first with pleuritic CP.
Then cough starts to produce rusty sputum.
