copd revised Flashcards
What is COPD?
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.
How does chronic bronchitis cause this lung damage that obstructs air flow?
Chronic bronchitis refers to long-term symptoms of a cough and sputum production due to inflammation in the bronchi.
How does Emphysema cause this lung damage that obstructs air flow?
Emphysema involves damage and dilatation of the alveolar sacs and alveoli, decreasing the surface area for gas exchange.
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
less common symptoms: weight loss, fatigue, swollen ankles
how can we asses breathlessness?
The MRC (Medical Research Council) Dyspnoea Scale is a 5-point scale for assessing breathlessness:
Grade 1: Breathless on strenuous exercise
Grade 2: Breathless on walking uphill
Grade 3: Breathlessness that slows walking on the flat
Grade 4: Breathlessness stops them from walking more than 100 meters on the flat
Grade 5: Unable to leave the house due to breathlessness
what is Alpha-1 Antitrypsin Deficiency?
Rare, inherited disease, can cause early onset COPD <45yrs
Alpha-1 antitrypsin (AAT) is a protease inhibitor made in the liver. It limits damage caused by activated neutrophils releasing elastase in response to infection/cigarette smoke
signs of Alpha-1 Antitrypsin Deficiency
Basal predominance to emphysema
Liver fibrosis or cirrhosis
effect of smoking on lung health
More respiratory symptoms and lung function abnormalities
Greater annual rate of decline in FEV1 (Fletcher-Peto Curve)
Greater COPD mortality rate than non-smokers
how is copd diagnosed?
based on clinical presentation and spirometry results.
Diagnose COPD if meets all following criteria:
Typical symptoms
>35 years
Presence of risk factor (smoking or occupational exposure)
Absence of clinical features of asthma
Airflow obstruction confirmed by post-bronchodilator spirometry
what will spirometry test show
Spirometry will show an obstructive picture with a FEV1:FVC ratio of less than 70%.
There is little or no response to reversibility testing with beta-2 agonists (e.g., salbutamol). Reversible obstruction is more suggestive of asthma.
how is the severity of COPD measured?
The severity can be graded using the forced expiratory volume in 1 second (FEV1):
Stage 1 (mild): FEV1 more than 80% of predicted
Stage 2 (moderate): FEV1 50-79% of predicted
Stage 3 (severe): FEV1 30-49% of predicted
Stage 4 (very severe): FEV1 less than 30% of predicted
what other investigations are done when copd is suspected?
Body mass index at baseline (weight loss occurs in severe disease)
Chest x-ray to exclude other pathology, such as lung cancer
Full blood count for polycythaemia (raised haemoglobin due to chronic hypoxia), anaemia and infection
Sputum culture to assess for chronic infections, such as pseudomonas
ECG and echocardiogram to assess for heart failure and cor pulmonale
CT thorax for alternative diagnoses such as fibrosis, cancer or bronchiectasis
Serum alpha-1 antitrypsin to look for alpha-1 antitrypsin deficiency
Transfer factor for carbon monoxide (TLCO) tests the diffusion of inhaled gas into the blood (reduced in COPD)
non-pharmacological management of COPD?
smoking cessation
vaccinations (pneumococcal and annual flu)
pulmonary rehabilitation
nutritional assessment
psychological support
pharmacological management of copd
mainly inhaled therapy
what are the groups of inhalers?
short acting bronchodilators
long acting bronchodilators
high dose inhaled corticosteroids
