Resp - COPD Flashcards
what is COPD?
Persisting respiratory symptoms due to airflow obstruction - usually progressive and not fully reversible. Encompasses:
- chronic bronchitis - chronic inflammation and fibrosis of small airways in response to noxious particles or gases, esp. smoking
- emphysema - alveolar wall destruction causing irreversible enlargement of air spaces distal to terminal bronchioles
- mucous gland hyperplasia
- loss of cilial function
name 3 possible causes of COPD
- smoking
- inherited a1-antitrypsin deficiency
- industrial exposure, e.g. soot
describe the possible symptoms and signs of COPD
Symptoms:
- exertional SOB
- chronic cough + regular sputum production
- wheeze
- frequent winter ‘bronchitis’
Signs (may be absent):
- hyperinflated chest
- pursed lip breathing and use of accessory muscles
- wheeze or quiet breath shounds
- reduced cardiac dullness on percussion
- peripheral oedema, raised JVP
- cyanosis
- cachexia
which classification system is used to assess impact of COPD on QoL?
MRC dyspnoea scale
I - not troubled by SOB except on strenuous exercise
II - SOB when hurrying or walking up a slight hill
III - walks slower than contemporaries on level ground due to SOB or has to stop for breath when walking at own pace
IV - stops for breath after walking about 100 m or after a few minutes on level ground
V - too breathless to leave house, or breathless when dressing or undressing
how would you diagnose a pt with COPD?
1) Spirometry - post-bronchodilator measurements:
- FEV1/FVC <0.7
- FEV1 >80% predicted
2) Further investigations - all pts should have at time of initial Dx:
- CXR (to exclude other pathologies)
- FBC (to ID anaemia or polycythaemia)
- BMI calculated
- pack-yrs calculated
how do you calculate pack-yrs?
(no. cigarettes per day / 20) x no. of yrs smoked
how does NICE classify severity of COPD?
Stage I: mild - FEV1 >80% predicted
Stage II: moderate - FEV1 50 -79% predicted
Stage III: severe - FEV1 30-49% predicted
Stage IV: very severe - FEV1 <30% predicted (or FEV1 <50% but with resp. failure)
describe your management of a pt with COPD
- Conservative Mx
- smoking cessation, inc. NRT, varenicline or bupropion
- offer vaccination for pneumonia and influenza
- offer pulmonary rehabilitation where indicated
- offer physiotherapy, inc. positive expiratory pressure (PEP) masks and active cycle of breathing techniques
- create COPD care bundle - Pharmacological Mx - start when all the above have been offered where relevant and Tx still needed to relieve symptoms.
- inhalers
- mucolytic therapy - consider in pts with chronic cough
- prophylactic antibiotics - in selected pts only
- long-term oxygen therapy - Surgical Mx
- bullectomy - for pts who are breathless and CT scan shows bulla occupying at least 1/3 of hemithorax
- lung volume reduction surgery - for pts with severe COPD who remain breathless with marked restrictions of activities of daily living, despite optimal medical therapy and if : FEV1 <50%, do not smoke, can complete 6 min walk distance of at least 140 m
when are different inhalers recommended in COPD?
- 1st line: SABA or SAMA as required to reduce SOB and improve exercise tolerance
- 2nd line:
- no asthmatic features suggesting steroid responsiveness: combined LABA + LAMA
- asthmatic features: LABA + ICS - 3rd line: triple inhaled therapy - LABA + LAMA + ICS for pts with asthmatic features/features suggesting steroid responsiveness
suggest possible complications of COPD
- chronic hypoxaemia causes slowly progressive pulmonary HTN with development of RV hypertrophy and possible cor pulmonale
- pneumothorax
- respiratory failure
- arrythmias, inc. AF
- infection
- secondary polycythaemia
- depression
what is a COPD exacerbation?
Acute, sustained worsening of a pt’s symptoms from usual stable state. Usually triggered by a viral infection; other causes inc. bacterial infections, air pollutants and ambient temp.
describe the symptoms of COPD exacerbation
- increased dyspnoea and cough (may develop resp. failure)
- increased wheeze and chest tightness
- if infective: change in sputum colour/volume, fever
- malaise, increased fatigue, reduced exercise tolerance, fluid retention
how would you manage a COPD exacerbation?
1/ A-E approach
2/ O2: aim for SaO2 88-92%
3/ salbutamol + ipratropium bromide nebulisers
4/ prednisolone 30 mg stat. and OD for 7 days
5/ antibiotics if raised CRP/WCC or purulent sputum
6/ consider:
- IV aminophylline
- NIV if T2RF and pH 7.25-7.35
- ITU referral if pH <7.25
