Clinical Features of COPD Flashcards
What is the definition of COPD?
Chronic, slowly progressive disorder characterised by airflow obstruction that does not change markedly over several months. Most of the the lung function impairment is fixed, although some reversibility can be produced by bronchodilator (or other) therapy.
What does the definition of COPD not mention?
NO mention of symptoms NO mention of bronchitis or emphysema NO mention of smoking
Why does obstruction of the airways occur?
Small-airway narrowing - and can be worsened by inflammation and mucus, leading to progressive breathlessness on exertion, along with coughing and wheezing.
What causes luminal occlusion?
Secretion of mucus and inflammatory exudate. Thickening of airway wall
What happens to the airway wall?
Thickens
ACOS?
Asthma, COPD, overlap syndrome
What happens to elasticity and alveolar attachments?
Loss of elasticity and disrupted alveolar attachments
What causes COPD (apart from smoking?)
Passive smoking Maternal smoking (Reduces FEV1 and increases respiratory illness) Air pollution Occupation (jobs exposing to dusts, vapours, fumes)
What are the two genotypes for alpha 1 antitrypsin deficiency? (75 variants)
Normal (86% UK) - PiMM Troublesome genotype (PiZZ)
What is the effect of alpha 1 antitrypsin ?
Neutralises enzymes released by neutrophils.
What percentage of smokers develop clinically significant COPD?
20%
What is a normal pack year?
Over 20
What is a pack year?
1 pack year = 1 pack a day for a year
What is the rate of decline of FEV1?
Non-smoker - 30 ml/yr SMOKER - 50 ml/yr
What is your typical COPD patient?
Patient 40+ years, smoker/ex-smoker, breathless on exertion, cough
What are the differential diagnosis for COPD?
COPD Asthma Lung cancer Left ventricular failure Fibrosing alveolitis Bronchiectasis Rarities: TB, recurrent pulmonary emboli
What separates COPD from asthma?
Asthma has variable airflow obstruction COPD, gradually worsens over the years
What are the symptoms of COPD?
Breathlessness Cough and Sputum Wheeze Weight loss Peripheral oedema
What is sputum like?
Clear or mucoid sputum
What does haemoptysis suggest rather than COPD?
Lung cancer/TB/bronchiectasis
What does weight loss indicate?
Severe disease, TNF alpha
What does peipheral oedema
Cor pulmonale (right heart failure secondary to lung disease), severe disease, respiratory failure
What is typical past medical history?
Asthma as a child, adolescence Respiratory diseases Ischaemic heart disease
What are the signs of COPD?
Breathless walking in to clinic, undressing
Pursed lip breathing, accessory muscles
Cyanosis CO2 flap, Tremor (beta-agonists), Effects of steroids: tissue skin, bruising, Cushingoid
Hyperexpanded chest
Laryngeal descent
Paradoxical movement of ribs and abdomen
Decrease cardiac dullness to percussion
Decreases in breath sounds (no crackles) Prolonged expiration with wheeze
Palpable liver
Cor pulmonale: increased jugular venous pressure, hepatomegaly, ascites, oedema
What is the interpretation of FEV1 of
What is the purpose of full pulmonary function testing?
Loking for emphysema
What is the effect of Gas trapping on lung volumes?
Increase in residual volume
Increase in total lung capacity
RV/TLC is greater than 30%
What are the findings in carbon monoxide gas transfer?
Decreased gas transfer
(decreased TLCO which is the diffusing capacity for carbon monoxide)
Decreased KCO (KCO measures the integrity of the blood–gas barrier)
What are the tests involved in the full pulmonary funciton testing?
Lung volumes
Carbon monoxide gas transfer
What is the response to oral corticosteroids and bronchodilators?
Minimal
What does significant bronchodilator/steroid response suggest?
asthma
What will a chest radiograph indicate?
Hyperinflated lung fields
Flattened diaphragms
Lucent lung fields
Bullae
(Can rule out bronchogenic carcinoma, interstitial disease, left ventricular failure)
What are the different type of blood gas measurements likely to be found?
What can a full blood count be indicative of?
Secondary polycthaemia
What does an ECG tell you?
Right axis deviation
P pulmonale (right atrial enlargement)
T wave inversion
What does sputum analysis indicate?
MC and S (Mucous culture and sensitivites) - S pneumoniae, H influenzae, M catarrahlis
What can be the cause of an acute exacerbation?
Usually precipitated by viral and bacterial infection
But consider sedative drugs, pneumothorax, trauma
What are the symptoms of an acute exacerbations?
Increase cough, sputum, sputum purulence, shortness of breath, wheeze, unable to sleep, increase oedema, confusion, drowsiness, cyanosis, breathless, flapping tremor, pyrexial
What is the management for Acute exacerbations?
Nebulised bronchodilator beta 2 and anti-muscarinic, O2, Oral/iv corticosteroid, antibiotic, diuretic, iv aminophyline, respiratory stimulant, NIV
