Obstructive diseases: Asthma, COPD, emphysema, bronchiectasis, chronic bronchitis Flashcards
Pathophysiology of Asthma
(1.) Chronic conditions characterised by airways obstruction that is reversible. Acute exacerbation can occur in response to triggers.
(2. ) Three factors contribute to airway narrowing:
- Bronchial hyperresponsiveness/contraction = triggers by a variety of stimuli can narrow airways more
- Mucosal swelling/inflammation caused by mast cell and basophil degranulation
- Increased mucus production further narrows airways
(3. ) This leads to recurrent episodes of wheezing, dyspnoea, cough.
(4. ) Episodes are often reversible either spontaneously or with treatment
RF for asthma
(1. ) Hx of atopy (tendency to develop allergic disease such as eczema, hayfever)
(2. ) Fx of asthma, atopy
(3. ) Precipitating factors: weather, allergen, smoking, infection, stress etc
(4. ) Is it occupational, exercise or seasonal induced?
Clinical features of asthma
(1. ) Breathlessness
(2. ) Cough
(3. ) Wheezing
(4. ) Diurnal variation = worse in the morning than in the evening
(5. ) Look for precipitating factors
How do you assess severity of asthma? (3)
Can be achieved with ‘RCP3’ questions:
- Recent nocturnal waking
- Usual asthma Sx in day
- Interference with ADLs? (activity of daily living)
- > if one of these are positive, it indicates poorly controlled asthma
Ix and Dx of asthma (6)
DX = requires an obstructive pattern and reversibility. Spirometry is 1st line
(1. ) PFT = will show airway obstruction: reduced FEV1 or FEV1/FVC ratio
(2. ) 2w PEFR diary = >20% variation on >3/7d for 2w
(3. ) Bronchial challenge test (mannitol, methacholine) or exercise test, show FEV1 >15% decrease
(4. ) Reversibility testing: FEV1 = >12% increase (improved) after beta-agonist-bronchodilator/glucocorticoid
(5. ) Exhaled FeNO = marker of eosinophilic inflammation
(6. ) Skin prick test may be done to identify allergen (atopic IgE asthma)
what would indicate controlled asthma (7)
(1. ) No daytime symptoms
(2. ) No night-time walking
(3. ) No need for rescue medication
(4. ) No asthma attacks
(5. ) No limitations on activity including exercise
(6. ) Normal lung function (FEV1 and/or PEF >80% predicted or best)
(7. ) Minimal side effects from medication
If medication fails what must you consider
If medication doesn’t work before moving up in step-wise mx:
(1. ) Check adherence and inhaler technique
(2. ) Advising correct use of a spacer with ICS therapy (including mouth rinsing after)
(3. ) Are they using NSAIDs, b-blocker? this will provoke asthma
Conservative Mx of asthma?
- Management of triggers
- Smoking Cessation
- Inhaler technique
Stepwise approach of asthma mx
- Stepwise treatment based on symptoms, guided by pt’s preference and competence.
- Move up or move down if control is good for >3months.
(1. ) SABA
(2. ) low-dose 200mg ICS
(3.) recheck technique + adherence
LTRA + low dose ICS
- If uncontrolled: LABA + ICS +/- LTRA
- If uncontrolled again: change to MART + ICS +/- LTRA
- MART contains ICS + fast-acting LABA
- If uncontrolled: inc MART ICS to 200-400mg and again to 800mg if fail -OR-
(4. ) High dose 2000mg ICS +/or trial fourth drug
- Fourth drug: muscarinic receptor antagonist (LAMA), SR theophylline or beta2agonist tablet
When would you offer an ICS for an asthmatic who’s currently using SABA only
Step-up in management is indicated if:
- Experienced an exacerbation in the last two years
- Used beta2-agonist inhaler more than three times per week.
- Symptoms of asthma for more than three times per week
- Waking due to asthma more than once per week
Management of acute asthma
- determine severity*
(1. ) Controlled oxygen
(2. ) Nebulised/inhaler SABA
(3. ) 30-40mg PO prednisolone
(4. ) Monitor oxygen saturation, heart rate, respiratory rate
How would you classify asthma attacks
(1.) Determine the severity based on consciousness, signs of exhaustion, resp rate, pulse rate, chest, BP, PEFR, oxygen saturation
(2. ) Moderate
- PEFR >50%, RR <25, <110bpm
- normal speech
(3. ) Severe
- PEFR 33-50%, RR >25, HR >110bpm
- inability to complete sentences
(4. ) Life-threatening
- PEFR <33%, SpO2 <92%
- altered consciouness, cyanosis, hypotension, silent chest
Preventer therapies in asthma
(1. ) ICS e.g. beclometasone
(2. ) Leukotriene receptor agonists
What is COPD?
(1. ) Chronic obstructive airway condition (or airway limitation) with acute exacerbations
(2. ) It is progressive with little/no reversibility
(3. ) It includes: emphysema, chronic bronchitis, small airway fibrosis
What is Acute COPD?
(1.) Usually occur due to a trigger (e.g., bacterial or viral pneumonia, environmental irritants) or in winter (cold air, virus).
(2. ) Sudden worsening of COPD Sx
- Wheezing with cough and breathlessness may become worse and may have more sputum
(3.) Change of Tx may be needed or hospitalisation.