What are the some of the respiratory causes of breathlessness upon exertion?
- Asthma
- COPD
- Pulmonary fibrosis
- Lung cancer
- Pulmonary embolism
- Pneumothorax
- Lower respiratory tract infection
- Allergies
What are some of the cardiovascular causes of dyspnoea?
- Congestive heart failure
- Pulmonary oedema
- Valvular defects
- Acute coronary syndrome
- Anaemia
- Renal/liver failure
- Deconditioning
What is the physiological mechanism behind dyspnoea?
The body needs more O2 than it is getting so the respiratory nuclei in the brainstem increase breathing rate to increase flow of air into the lungs.
What is the MRC breathlessness scale?
1: Not troubled by breathlessness except on strenuous exercise
2: Troubled by shortness of breath when hurrying/ walking up hill
3: Walks slower than people or has to stop for breath when walking at own pace
4: Stops for breath after walking about 90m or after a fews mins on flat
5: Too breathless to leave the house/ breathless when dressing
What clinical examinations are taken when someone complains of breathlessness?
- Spirometer
- Measure Respiratory rate
- Monitor vitals (HR, BP, Temp)
- Check for swollen lymph nodes (infection0
- Check O2 saturation
- Auscultate heart + lungs
What investigations take place when someone complains of breathlessness?
- Chest X-ray
- ECG ( to check for arrythmias)
- Full blood count
- Thyroid function test
- Urine + electrolytes test
- Blood glucose
What is FEV1?
A volume of air exhaled forcefully in 1 second, after taking a deep exhalation.
What is FVC?
Forced vital capacity: the volume of air expired upon deep inhalation.
What would the FEV1/FVC ratio be for a normal person?
~70-80%
What are obstructive diseases? Describe the FVC + FEV1 of this type of disorder.
- Diseases where exhalation cannot occur due to airway resistance -> their lungs can’t empty as quickly.
- Reductions in both FVC and FEV1
Give some examples of obstructive conditions.
- COPD
- Asthma
- Cystic fibrosis
What are restrictive diseases? Describe the FVC + FEV1 of this type of disorder.
HINT: think of bear hugs
- Diseases where inhalation/filling up the lungs is difficult
- Proportional reduction in both FEV1 and FVC
Give some examples of restrictive conditions
- Pulmonary fibrosis
- Obesity
- Congestive heart failure
- Neuromuscular disorders
Describe the FEV1/FVC ratios of obstructive disorders.
<70%
Describe the FEV1/FVC ratios of restrictive disorders.
~100%
What are the 2 (or 3) conditions that make up COPD?
- Emphysema
- Chronic bronchitis
(- Small airways disease)
What is emphysema?
Damage to alveoli through the destruction of their walls.
This reduces…
- their SA
- their elasticity (abnormal enlargement because they remain stretched even during deflation ).
Less ventilation as there’s more dead space.
What is chronic bronchitis?
- Inflammation of the bronchi
- Increased mucosal secretion
- Loss of cilia
- Collapsing of airways on exhalation (gas trapping)
How does smoking cause chronic bronchitis?
- > mutagens cause hypertrophy and hyperplasia of goblet cells.
- > cilia becomes shorter and less mobile so mucus can’t be moved out as quickly.
How is asthma different to COPD?
- COPD affects both the airways and the parenchyma. The inflammation is run by CD8 and neutrophils
- Asthma only affects the airways. This inflammation is run by eosinphils and CD4 cells.
How would COPD look in a Chest X-ray?
- Hyperinflated lungs (very uncomfortable for the patient because it takes more effort/ more energy to inflate lungs). The signs are:
- > More than 7 anterior ribs are visible
- > Flattening of the diaphragm
- > Heart may appear small and narrow
- Gas trappings
- Build up of air near the apex of the lungs
- Bullae (pockets of air as a result of emphysema)
What are the non-medical ways to treat COPD?
- Smoking cessation
- Nutrition
- Avoiding lower respiratory tract infections
What are the different smoking cessation treatments?
- Nicotine replacement therapy (Varenicline; Bupropion)
- Counselling/support groups
- Set a quit date
- Transdermal patch
How can you avoid lower respiratory tract infections?
- Isolation
- Getting vaccinated against the flu/ pneumonia
- Stay out of the cold
