COPD Flashcards
State the symptoms of COPD.
Breathlessness Cough (with sputum) Wheeze on exertion Chest tightness Weight loss / loss of muscle mass Recurrent winter bronchitis Peripheral oedema (cor pulmonale) Symptoms are gradually progressive and worsening No variability in symptoms
what are risk factors for COPD?
Smoking Chronic asthma passive or maternal smoking Air pollution Occupation (dust in coal mines) alpha 1 anti trypsin deficiency
what are the differentials of COPD?
asthma
bronchiectasis
When diagnosing COPD, what is needed in the history?
Symptoms, age, smoking (if they do smoke, have ever smoked and for how long), recurrent chest infection / winter bronchitis, asthma as a child, if symptoms are worsening.
Describe the essential investigations that are used to diagnose COPD.
spirometry - FEV1/FVC < 7.0 or < 80% predicted pulmonary function tests ABG CXR FBC reversibility to bronchodilators ECG (if suspect cor pulmonale)
When trialling a potential patient with COPD on bronchodilator and corticosteroid therapy, what are the doses / length of time prescribed?
And also how are these results interpreted?
(Baseline)
10 mins post neb 2.5-5mg salbutamol
30 mins post neb 2.5-5mg salbutamol + 500ug ipratropium
(Baseline)
30-40 mg prednisone needed daily for 2 weeks (0.6mg/kg)
Measure baseline and final FEV1
Significant reversibility = FEV1 > 200ml / > 15% baseline
Significant reversibility suggests asthma / asthmatic component
COPD = insignificant bronchodilator/steroid response
Describe the useful investigations that can be carried out to help diagnose COPD.
Bedside: FBC, ECG, ABG, ESR.CRP
Sputum culture (if evidence of exacerbation)
Chest X-ray: hyperinflated lung fields, flattened diaphragm, bullae
Spirometry: FEV1/FVC < 0.7
What signs should you look for in patients who may have COPD.
hyper resonant lungs on percussion decreased cardiac dullness to percussion decreased breath sounds prolonged expiration with wheeze use of accessory muscles for breathing pursed lip breathing barrel chest / hyper expanded chest laryngeal descent loss of muscle mass / weight loss peripheral oedema , hepatomegaly, elevated JVP, loss of P2 (cor pulmonale)
Describe the inhaled drug therapy which may relieve some symptoms of COPD.
Short acting Bronchodilators:
SABA- salbutamol
SAMA - ipratropium
Long acting bronchodilators
LAMA - long acting anti-muscarinic agents
LABA - long acting B2 agonists
High dose inhaled corticosteroids (ICS) and LABA
Relvar
Fostair MDI
What are the differential diagnoses of COPD.
Lung cancer Asthma Left ventricular failure Fibrosing alveolitis Bronchiectasis Rarities - TB and recurrent pulmonary emboli
describe the pathophysiology in COPD.
increased airway resistance
enlargement of mucous secreting glands
remodelling of the airways
- alveolar walls are damaged resulting in fewer, larger alveoli
- bronchioles become narrowed and clogged with mucous
hypoxia and vascular bed changes resulting in pulmonary hypertension
Pathophysiologically, what are the 3 main causes of airway limitation in COPD?
- Loss of alveolar attachment of airways and loss of elasticity (due to emphysema) - This reduces elastic recoil so small airways collapse on expiration
- Inflammation and scarring - causes small airways to narrow
- Mucous secreting cells hyperplasia - blocks airways.
describe some clinical differences between COPD and asthma.
COPD > 35yr olds where asthma occurs in any age
symptoms in COPD are persistent and progressive whereas in asthma they are intermittent and variable.
COPD there is no family history - Asthma there is usually history in the family
nocturnal symptoms are uncommon in COPD but common in asthma
cough in COPD is persistent and productive whereas in asthma it is intermittent and non productive
how is the severity of COPD categorised?
Gold criteria - FEV1; < 80% predicted = mild < 50-79% predicted = moderate < 30-49% predicted = severe < 30% = very severe
what is the criteria for putting a COPD on long term oxygen?
Pa02 < 7.3 Pka
or Pa02 7.3-8 Pka if there is polycythaemia, for pulmonate, nocturnal hypoxia or pulmonary hypertension.
what do you assess in a patient for acute exacerbation COPD (AECOPD) ?
Increasing breathlessness cough sputum volume sputum purulence wheeze chest tightness
when would you consider hospital admission in a patient with AECOPD?
tachypneoic
hypotensive
low oxygen saturation (< 90-92%)
describe the ward assessments that have to be carried out if a patient is admitted with AECOPD.
Oxygen saturation 88-92%
Medication i.e. nebulised bronchodilators (if they cannot take inhalers) and corticosteroids
Antibiotics if there is infection (oral or IV)
Assess for respiratory failure (test arterial blood gas ABG) If in respiratory failure ventilation will be required.
what does spirometry measurement of lung function involve?
FEV1 / FVC
what is the normal FEV1 and FVC values?
FEV1 = 3.5- 4 litres
FVC = 5 litres
therefore FEV1/FVC should be 70-80% (> 0.7 - 0.8)
what is obstructed lung disease defined as on spirometry?
FEV1/FVC < 70%
what is the pathophysiology of chronic bronchitis causing obstruction in the large and small airways?
large airways:
- goblet cell and mucous gland hyperplasia.
- inflammation and fibrosis
small airways:
- goblet cells appearing
- inflammation and fibrosis sin long standing disease
what are the 3 different pathological forms of emphysema?
centriacinar
panacinar
periacinar
describe what periacinar emphysema is.
periacinar emphysema also known as bullous/bleb emphysema
lungs contain emphysematous bullae which are airfilled bullae >1cm.
the bullae are like the blebs which can develop just under the pleurae
in emphysema (and therefore COPD), what does it show on CXR?
hyperinflated lung fields
what is the definition of chronic bronchitis?
chronic sputum production for at least 3 consecutive months for 2 years
why does cor pulmonale cause pulmonary hypertension?
hypoxia caused by cor pulmonale results in pulmonary vasoconstriction as well as;
pulmonary arteriole hypertrophy and intimal fibrosis
loss of capillary bed
secondary polycythaemia
why does cor pulmonale result in shunt?
cor pulmonale results in hypoxaemia therefore shunt occurs due to pulmonary arteriole constriction to prevent blood flow to alveoli that don’t have oxygen
what is FL02?
fraction of inspired air which is oxygen
what is complicated chronic bronchcitis?
when the sputum becomes mucopurulent and is infected
