Chronic asthma Flashcards
Describe the pathophysiology of asthma
- Chronic bronchial inflammation:
- T lymphocytes, mast cells, eosinophils
- Smooth muscle hypertrophy
- Epithelial damage
- Mucus plugging
- Reversible variable airway obstruction
- Airway hyper-responsiveness
Name three asthma phenotypes
- Allergic: eg. dust mites, pollens, animal
- Non-allergic: chemical and biological products
- Respiratory infection: often starts in middle age
- Exercise-induced
- Brittle asthma: recurrent severe attacks
- Steroid-resistant asthma
Define atopy
Genetic tendency to develop allergic IgE-mediated diseases
Includes asthma, allergic rhinitis, and dermatitis/eczema
Name four characteristic clinical features of asthma
Episodic or daily/seasonal variation of: worse at night and morning
- Expiratory polyphonic wheeze; respiratory distress
- Cough: often nocturnal
- Chest tightness
- Dyspnoea
- Variable expiratory airflow limitation
Symptoms can be triggered by factors
May resolve spontaneously or with medication
Suggest two questions to check for possible occupational asthma
- Are symptoms better on days off work?
- Are symptoms better when on holiday?
Outline the diagnostic criteria of chronic asthma in adults
Asthma symptoms plus +ve objective tests
- FeNO: (aged 17+) ≥40 parts per billion (ppb)
- Spirometry: FEV1/FVC <70%
- Bronchodilator reversibility (BDR): ≥12% improvement in FEV1
Consider
- Peak expiratory flow variability over 2-4wks: >20% variability
- Direct bronchial challenge test: PC20 <8 mg/ml
Outline the diagnostic criteria of chronic asthma in children
Asthma symptoms plus +ve objective tests
-
FeNO: (aged 5-16) ≥35 ppb
- Children if diagnosis uncertain with normal spirometry/-ve BDR test
- Spirometry: FEV1/FVC <70%
Consider
- Bronchodilator reversibility (BDR): ≥12% improvement in FEV1
- Peak expiratory flow variability over 2-4wks: >20% variability
Outline the diagnostic criteria for asthma in young children <5yr
- Asthma symptoms on observation and clinical judgement
- Not indicated for objective tests till aged 5
Name five possible reasons for uncontrolled asthma
- Alternative diagnoses
- Lack of adherence
- Suboptimal inhaler technique
- Smoking
- Seasonal or environmental factors
- Occupational exposures
- Psychosocial factors
List 5 differentials of eosinophilia
- Airway inflammation: asthma or COPD
- Allergic rhinitis
- Allergic bronchopulmonary aspergillosis
- Drugs
- Eosinophilic granulomatosis with polyangiitis
- Eosinophilic pneumonia
- Lymphoma
- SLE
- Hypereosinophilic syndrome
Provide instructions for how to use a metered-dose inhaler
- Shake canister
- Exhale fully
- Placed aerosol nozzle in mouth - tight seal
- Rapid inhalation whilst pressing the aerosol
- Inhalation complete
- Hold breath for 10s if possible
Good technique still only inhales 15%. Spacer is useful for children and elderly.
Outline the initial management for chronic asthma in adults
- SABA reliever therapy
- Low dose ICS maintenance therapy
Outline the initial add-on therapy for chronic asthma after SABA + ICS
Offer leukotriene receptor antagonist (LTRA)
Review response to treatment in 4-8 weeks
What is offered for asthma in adults uncontrolled by ICS + LABA?
- Offer LABA in combination with ICS
- Review continuation of LTRA
How should asthma therapy in adults be altered if uncontrolled with low dose ICS + LABA?
Change LABA + ICS to a MART (combined LABA + low dose ICS) regimen
How is adult asthma therapy changed if uncontrolled by MART regimen?
Either
- Adjust MART to include moderate dose ICS
- Fixed dose regimem moderate dose ICS + LABA, with SABA reliever
What changes are made to adult asthma management if uncontrolled by MART with moderate dose ICS or fixed-dose regiment?
Either:
- Fixed dose regimen: high dose ICS, with SABA reliever
- Trial of additional drug eg. LAMA or theophylline
- Seek expertise from asthma specialist
Outline the initial management of asthma in children
- SABA reliever therapy
- Paediatric low dose ICS
What is the next step in childhood asthma management if uncontrolled by SABA + low dose ICS?
Add-on LTRA
Review treatment response in 4-8 weeks
How is childhood asthma therapy changed if uncontrolled by LTRA + ICS?
- Consider stopping LTRA
- LABA + paediatric low dose ICS
Outline the next step in childhood asthma medication if uncontrolled by LABA + paediatric low dose ICS
Change ICS + LABA to a MART regimen (combined low dose ICS + LABA)
How is childhood asthma treatment changed is uncontrolled by MART (combined low dose ICS + LABA)?
Either
- Adjust MART to contain paediatric moderate dose ICS
- Fixed-dose regimen of moderate dose ICS + LABA, with SABA reliever
What is the next step if childhood asthma is uncontrolled with MART (combined moderate dose ICS + LABA) or fixed-dose regimen?
Either:
- Seek expert advise from asthma specialist
- Fixed-dose regiment of paediatric high dose ICS with SABA reliever
- Trial additional drug eg. theophylline
Give three self-management steps for asthma management
- Asthma self-management programme
- Personalised action plan
- Education
- Increased dose of ICS (adults) for 7d if asthma deteriorates
- Weight loss
- Smoking cessation
- Breathing exercise programmes
Outline the management for asthma in young children <5yrs
SABA reliever ± maintanence therapy:
- 8/52 trial of paediatric moderate dose ICS
- Not resolved: likely alternative diagnosis
- Recurred within 4/52 after trial: paediatric low dose ICS
- Recurred beyond 4/52 after trial: repeat trial of ICS
- Consider additional LTRA
- Stop LTRA and refer to asthma specialist
