Obstructive airway diseases Flashcards
(30 cards)
Define COPD
Chronic, progressive lung disease characterised by irreversible airway obstruction
Formally divided into emphysema and chronic bronchitis
Define emphysema
Irreversible enlargement of the airways distal to the terminal bronchioles
Define chronic bronchitis
Persistent cough present for at least 3 months of the year, for at least 2 years
Describe the epidemiology of COPD
Common lung disease worldwide
3rd most common cause of death
Affects older adults (65+)
Describe the aetiology of COPD
RFs: smoking, indoor burning of fuel (eg fires), occupational exposure to gases/particles
- Chronic airway inflammation
- > airway remodelling (increased goblet cells, SM hypertrophy, alveolar loss) -> sputum, airway resistance - Cilia dysfunction
Describe the presentation of COPD
65+ ex-smoker with
- Chronic productive cough
- SOB, esp on exertion
- Wheeze
- Weight loss
Describe the signs of COPD on examination
General: tachypnoeic, flushing/cyanosis
Hands: palmar erythema, asterixis, cyanosis
Chest: barrel chest, hyper-resonance on percussion, polyphonic wheeze/inspiratory crackles
Describe the investigations for COPD
History and examination
Spirometry
Bloods for young patients eg. LFTs
CXR
Exacerbation:
- Sputum sample
- ECG
- Bloods: FBC, CRP, U+Es, ABG, culture
- CXR
Describe the spirometry results in COPD
Reduced FEV1/FVC (<0.70) Reduced FEV1 (used to stratify severity)
Describe the long term management of COPD
Conservative:
- Exercise, smoking cessation
- Vaccination
- Pulmonary rehab
Medical:
- Inhaler therapy:
- 1st line: salbutamol rescue inhaler
- 2nd line: LABA+LAMA (non-asthmatic features) or LABA+ICS (asthmatic features)
- 3rd line: triple therapy LABA+LAMA+ICS
- Prophylactic ABx- frequent exacerbations. Azithro.
- Additional oral meds: Roflumilast, theophylline
- Oxygen therapy
Describe the indications for home oxygen therapy
Assess ABG on 2 occasions, 3 weeks apart
Suitable for LTOT if: NON smoker +
-PaO2 <7.3 when stable
-PaO2 7.3-8 when stable if also: polycythaemia, pulmonary HTN, RHF
Describe the management of COPD exacerbations
- Bronchodilators: nebulised/inhaled (specify gas)
- Oral corticosteroids: 30mg for 5 days
- Antibiotics if indicated. 5 days Amox/doxy/clari. Send sputum culture also
- Oxygen therapy (specify sats goal)/ NIV/ invasive ventilation
Define asthma + describe pathophysiology
Chronic inflammatory airway disease characterised by
1) intermittent reversible airway obstruction
2) airway hyperresponsiveness
3) airway inflammation
Over time, remodelling occurs w SM hypertrophy, etc
Describe the epidemiology of asthma
Very common
Affects developed countries > developing, hygiene hypothesis
Genetic predisposition
Describe the presentation of asthma
Episodes of:
-Dry cough, worse at night. Diurnal variation
-Wheeze
-SOB
-Chest tightness
Various triggers: exertion, cold weather, allergens, viral infection
Between episodes, symptom free
Describe the signs of acute + chronic asthma on examination
General: tachypnoea, tachycardia, increased work of breathing + use of accessory muscles, cyanosis, difficulty speaking, drowsiness, etc
Chest: widespread polyphonic wheeze -> quiet chest, hyperinflated chest + Harrison’s sulci (chronic)
Describe the different severity of asthma attacks (criteria)
Mod:
- Normal sats
- PEFR >50% expected
Severe:
- PEFR 33-50% expected
- RR >25, HR >110
- Unable to complete full sentences
Life-threatening:
- PEFR <33% expected
- Silent chest
- Drowsy/exhausted
- Cyanotic
- Sats <92%
- Rising PaCO2
Describe the investigations for chronic asthma
History + examination suggestive ->
- Offer FeNO test (>40 is positive)
- Offer spirometry (<0.70 is Dx of obstructive disease) + reversibility test (^ of 12% is significant)
1. Dx uncertainty: monitor PEF variability for 2-4 weeks (>20% is positive)
2. Dx clear: start treatment
Describe the management of chronic asthma
Conservative:
- Education, avoid triggers
- Smoking cessation
- Vaccinations
Medical:
All patients: SABA- salbutamol PRN
-1st step: SABA + low dose ICS BD
-2nd step: SABA + ICS + LABA (BTS) or LTRA (NICE)
-3rd step: increase dose of ICS to medium. Stop LABA if not effective. Add LTRA/LABA
-4th step: refer.
Describe the management of acute asthma
History + exam / A to E approach
- Measure sats + give high flow O2 if required
- Gain IV access, take bloods and ABG if needed
Mx:
- Mod attack: inhaled SABA
- Sev/life-threatening:
1. Nebulised SABA (5mg every 20-30mins)
2. Nebulised ipratropium (0.5mg 4-6hourly)
3. Oral steroids (PO pred 40-50mg)
4. IV Mg sulphate (1.2-2g infusion over 20mins)
5. IV SABA
6. IV aminophylline
Monitoring:
- Cont sats monitoring
- PEFR after 15-30 mins, repeat as needed
When should inhaled steroids be considered?
In anyone who has:
- Had an asthma attack
- Using SABA >3x/week
- Symptomatic 3x/week or more
- Waking during the night (1+/week)
Describe the important parts of an asthma review
-Current medication
-Symptom control: frequency per week, asthma control score etc
-Bronchodilator use frequency
-Asthma attacks/ED visits/hospitalisations
-ICE
If poor control: medication adherence, inhaler technique
Describe the side effects of beta 2 agonists
Tachycardia, palpitations Sweating Tremor Anxiety **Increased risk of death with LABA alone (without ICS) Caution in CVD
What is the typical dose of salbutamol?
100-200mcg, up to 4x daily
