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.
Rf for COPD
(1. ) Male
(2. ) >35y
(3. ) Smoking
(4. ) Second-hand smoking (occupational, exposure)
(5. ) Genetic = AATD
(6. ) Low socioeconomic background
Clinical Features of COPD (8)
(1. ) Chronic + productive cough
(2. ) Progressive dyspnoea
(3. ) Wheeze
(4. ) Cachexia (wt loss, muscle wasting)
(5. ) Hyper-inflated chest
(6. ) Pursed lip breathing, use of accessory muscles
(7. ) Cor pulmonale Sx
(8. ) Cyanosis
Describe the progression of dyspnoea in COPD (MRC scale)
Grade 1 - breathless during exercise/exertion
Grade 2 - SoB when walking up hill
Grade 3 - SoB on walking
Grade 4 - SoB and pausing during walks
Grade 5 - SoB is distressing, housebound
Dx of COPD
(1.) Based on typical clinical features supported by spirometry (post bronchodilator: FEV1/FVC <0.7).
(2. ) Suspect COPD in >35y with risk factors (smoking, occupational or environmental exposure) and one or more of the following symptoms:
- Breathlessness
- Chronic/recurrent cough
- Regular sputum production
- Frequent LRTI
- Wheeze
- Other Sx = wt loss, anorexia, fatigue, waking at night with breathlessness, etc
Ix for COPD
(1. ) Spirometry and SABA/SAMA
- FEV1 = <80%
- FEV1/FVC = <0.7
- Severity assessed with FEV1
Extra tests:
(2. ) CXR
- hyperinflation, flattened diaphragm
- may see bullae if emphysema
(3. ) ECG
- Cor Pulmonale = peaked p wave, right axis deviation
(4. ) ABGs
- if very low FEV1 and dyspnoea
How is severity of COPD assessed?
- Severity of airflow limitation can be assessed with FEV1
- Stage 1 Mild = >80%
- Stage 2 Moderate = 50-79%
- Stage 3 severe = 30-49%
- Stage 4 Very severe = <30%
What are the aims of Tx in COPD
Reduce Sx
- Relieve Sx
- Improve exercise intolerance
- Improve health status
- Improve QoL
- Reduce exacerbations
Reduce risk
- Prevent/slow down disease progression
- Prevent and treat exacerbations
- Reduce mortality
How is acute COPD managed?
(1. ) Emergency Admission: Severe breathlessness, Rapid onset of Sx, Confusion, impaired consciousness etc
(2. ) Inc inhaled SABA/SAMA dose (short-acting bronchodilators)
(3. ) Consider Oral corticosteroids
(4. ) PO Abx (amoxicillin, doxycycline, clarithromycin) if infection present:
- Change in sputum: colour, thickness, volume
- Previous sputum culture and susceptibility results.
(5. ) Identify triggers
(6. ) Non-invasive ventilation (NIV): Improves resp acidosis, dec RR, severity of dyspnoea
Mx of COPD
Non-pharmacological
(1. ) Smoking cessation
(2. ) Pulmonary rehabilitation
(3. ) Flu and pneumococcal vaccines
(4. ) Optimise tx for comorbidities
Pharmacological, if above fails
(1. ) Offer SABA or SAMA
(2. ) If still limited by Sx or has exacerbations:
(a. ) Offer LABA + LAMA (if FEV >50%, no asthmatic features)
(b. ) Offer LABA + ICS (if <50%, asthmatic features)
(3. ) Consider 3-month ICS if
- still no response to above
- day-to-day sx that impact QoL
- 1 severe or 2 moderate exacerbations within a year
When is long-term oxygen therapy indicated in COPD pts?
(1. ) Pts with chronic resp failure, failure of tx, pulmonary HTN, oedema, polycythaemia
(2. ) SATS <93%, PaO2 <7.3, FEV1 <30%
(3. ) CI = smokers
What differences are there between asthma and COPD?
(1. ) Age
- COPD >35y, Asthma: <35y
(2. ) RF
- COPD = smoking, second hand smoking, Fx AATD
- Asthma = pollen, exercise, smoke, stress etc, Fx asthma, atopy
(3. ) Clinical features
- COPD = productive cough, progressive breathlessness, minimal variation
- Asthma = non-productive cough, intermittent breathlessness, diurnal variation
(4. ) Spirometry post bronchodilator
- COPD: FEV1/FVC <0.7
- Asthma: FEV1 improves (reversibility)
What would you see on a spirometry for restrictive and obstructive lung disease?
(1. ) Both present with low FEV1 <80%
(2. ) FVC = reduced (restrictive), close to normal (obstructive)
(3. ) FEV1/FVC = >0.8 (restrictive), <0.7 (obstructive)
(4. ) Examples = Restrictive - IPF, Obstructive - asthma, COPD
Bronchiectasis: patho, Sx, complications
(1. ) Dilation of bronchi due to inflammation
(2. ) Inflammation, secretion, infections causes obstruction
(3. ) Lung tissue can’t absorb as much oxygen due to this damage
(4. ) Sx = chronic cough, large quantities of foul smelling sputum +/- blood
(5. ) Complications = recurrent pneumonia, fungal infection, metastatic abscess e.g. brain, heart, cor pulmonale
Chronic Bronchitis: patho, Sx, complications
(1. ) Chronic inflammation and mucus hypersecretion with bronchial mucous gland hypertrophy leading to squamous metaplasia.
(2. ) Productive cough (cough and sputum) for 3m in 2 consecutive years. Other Sx = hypercapnia, hypoxia, cyanosis, RHSF +/- resp failure etc
(3. ) RF = smoking-induce (tobacco or environment), middle aged
(4. ) These individuals are prone to recurrent bronchial infections
Emphysema: patho, Sx, aetiology, complications
(1. ) Enlargement of alveolar airspaces with destruction of elastin -> bullae
(2. ) This has a ‘gas trapping’ effect i.e. prevent full exhalation of air [obstructive disease], leading to progressive loss of lung functionality
(3. ) Aetiology: cigarette smoke, coal dust exposure, cadium toxicity, alpha-1-antitrypsin deficiency
(4. ) Complications: NO inc cancer risk, but instead pulmonary HTN, poor oxygen delivery to tissues
