Asthma Flashcards
List 4 characteristic clinical features of asthma
- cough
- Dyspnoea
- Wheeze
- Chest tightness
List the features that characterise a moderate asthma attack
- Worsening symptoms
- No features of acute severe asthma
- PEFR >50% of best/predicted
List the features that characterise an acute severe asthma attack
- Inability to complete sentences in a single breath
- PEFR <50% of best/predicted
- RR ≥ 25
- HR ≥ 110
List the features that characterise a life-threatening asthma attack
- Poor respiratory effort
- Cyanosis
- Silent chest
- Hypotension
- Arrhythmia
- Exhaustion
- Reduced conscious level
- PEFR < 33% of best/predicted
- SpO2 < 8KPa
- Normal PaCO2 = 4.6 - 6.0 kPa
What is the initial treatment for acute asthma?
- Sit upright
* Salbutamol 5mg and ipratropium bromide 0.5 mg via oxygen-driven nebuliser
Should patients display an inadequate response to initial therapy, what further treatments can be given?
- Repeat salbutamol 5mg via oxygen-driven nebuliser if inadequate response and give prednisolone 40mg orally (PO) or hydrocortisone 100mg IV if unable to swallow.
- Consider “back-to-back” salbutamol nebulisers or continuous salbutamol nebuliser 5-10 mg/h if inadequate response.
- Consider magnesium sulphate 1.2-2.0g IV over 20 minutes in life threatening or near-fatal asthma or in acute severe asthma with an inadequate response to initial therapy
- consider aminophylline 5 mg.kg IV loading dose over 20 minutes followed by 0.5 mg/kg/h IV maintenance dose in life-threatening or near-fatal asthma with an inadequate response to initial therapy.
What features would concern you on an ABG in acute asthma?
- Low pH
- PaCO2 >4.6kPa
- PaO2 < 8kPa
What are the indications for requesting a CXR in acute asthma?
- suspected pneumothorax or consolidation
- life threatening asthma
- Failure to respond to initial therapy
- Requirement for ventilation
What criteria would mandate admission for acute asthma?
- Life-threatening asthma
- Near-fatal asthma
- Acute severe asthma persisting despite initial therapy
What criteria must be achieved to consider discharge following acute asthma?
- PEFR > 75% of best/predicted 1 hour after initial therapy
What would you check before discharge?
- Give prednisolone 40 mg once daily for 5 days
- Check inhaler technique and ensure sufficient, in-date inhaled bronchodilator
- Arrange follow up with GP in two days
What is the definition of asthma and what are the 3 main components?
- Chronic inflammatory disease of the airways.
- 3 components:
1. Reversible and variable airflow obstruction
2. Airway hyper-responsiveness to stimuli
3. inflammation of the bronchi
What is the Epidemiology of Asthma?
- Increasing prevalence - estimates of prevalence range from 3-5.4 million
- Approximately 235 million people worldwide affected
- Approximately 250,000 people die per year form the disease
What is the aetiology of asthma?
- Atopy and allergy - pets, pollen
- cold air
- Exercise
- Pollution
- Occupational
- e.g. isocyanates (paint sprayers), latex, flour, and grain dust
- Viral infections
- Drugs
- E.g. NSAIDs, Beta Blockers
- Emotion
What are the main presentations of asthma?
- Cough
- Wheeze
- Breathlessness
- Chest tightness
Which features increase the probability of asthma?
- Diurnal variation (worse at night and early morning)
- Triggered by or made worse by aetiologies e.g. cold air
- Recurrent and frequent symptoms
- Family history of atopy or asthma
What are the differential diagnosis of asthma
- Respiratory
- Churg-Strauss: Look for high eosinophils
- Allergic bronchopulmonary aspergillosis: Allergy testing for common moulds
- COPD (exacerbation)
- Chronic cough syndromes
- Rhinitis
- Bronchiectasis
- Sarcoidosis
- Lung cancer - In children
- Croup and epiglottitis
- Obliterative bronchitis
- Cystic fibrosis/Ciliary dyskinesia - GORD
- Heart failure
- Tracheomalacia: Narrow trachea on bronchoscopy, obstructive picture on spirometry
- Vocal cord dysfunction
What is used to investigate Asthma?
- Peak flow charts
- Lung function tests
- FEV1/FVC < 0.7
- Reversibility/ improvement after trial treatment
- CXR
- In patients presenting atypically or with additional symptoms or signs
- Tests of atopy
- Skin prick testing
- Blood eosinophilia
- Raised specific IgE
What further investigations for asthma can be carried out?
- Methacoline PC20 - the provocative concentration of methacholine required tor cause a 20% fall in FEV1…
- FEno - Exhaled NO concentration
- Indirect challenges - e.g. exercise challenge
- Sputum eosinophil count
What investigations are carried out in acute asthma?
- CXR
- Recommended in the presence of suspected pneumothorax, consolidation, life threatening asthma, requirement for ventilation, failure to respond to treatment - Pulse oximetry
- ABG.
What are the different stages of acute asthma?
- Moderate asthma
- Acute severe asthma
- Life-threatening asthma
- Near-fatal asthma
What are the features of moderate asthma?
- Increasing symptoms
- PEF > 50-75% best or predicted
- No features of acute severe asthma
What are the features of acute severe asthma?
Any one of:
- PEF 33-50% best or predicted
- Respiratory rate ≥ 25/min
- Heart rate >110 min
- Inability to complete sentences in one breath
What are the features of life threatening asthma?
Any one of the following in a patient with severe asthma:
- Clinical signs:
- Altered conscious level
- Exhaustion
- Arrhythmia
- Hypotension
- Cyanosis
- Silent chest
- Poor respiratory effort - Measurements
- PEF < 33% best or predicted
- SpO2 < 92%
- PaO2 < 8 kPa
- “normal” PaCO2 (4.6-6.0 kPa)
What is the main feature of near-fatal asthma?
Raised PaCO2 and/or requiring mechanical ventilation with raised inflation pressures.
What is the initial management of acute asthma?
- Oxygen: aim sats 94-98%
- Inhaled/Nebulised high dose beta 2 agonists - e.g. 2.5-5mg nebulised salbutamol at 15-30min intervals
- steroid therapy
- 40mg prednisolone po daily for 5 days. if oral route not possible - IV hydrocortisone 400mg daily or IM methylprednisolone 160mg daily
O - SHIT.
What is the management for patients who are failing to respond to initial treatment or with acute severe or life threatening asthma?
- Nebulised ipratropium bromide - 0.5mg 4-6 hourly
- Magnesium sulphate - 1.2-2g IV infusion over 20 minutes
- IV aminophylline - 5mg/kg loading dose IV over 20 minutes (unless already on oral therapy), then infusion of 0.5-0.7mg/kg/hr - if on oral maintenance therapy, check level on admission. - monitor levels whilst on infusion (aim 10-20mg/l)
- Early referral to ITU indications include:
- Deteriorating PEF
- Persisting or worsening hypoxia
- Hypercapnia
- Fall in pH in ABG
- Exhaustion
- Reduced GCS
How is chronic asthma managed non-pharmacologically?
- Self-management plan
- Allergen avoidance
- Smoking cessation
- Immunisations
- Immunotherapy
How is chronic asthma managed pharmacologically?
Using a step wise approach, which you can move up or down..
What are the steps involved in the pharmacological management of chronic asthma?
Step 1: Reliever therapy Step 2: Regular preventer therapy Step 3: Add- on therapy Step 4: Addition of a 4th drug Step 5: Oral steroids
What is step 1 of chronic asthma management?
Step 1: Reliever therapy
- Short acting beta-2 agonist as required: Salbutamol 100-200mcg
What is step 2 of chronic asthma management?
Step 2: Regular preventer therapy
- Introduce inhaled steroid if: exacerbations in last 2 years; using salbutamol 3x/wk; symptomatic 3x/week; waking one night/wk
- Usual starting dose 200mcg bd (Budesonide – alternatives include beclomethasone and fluticasone)
What is step 3 of chronic asthma management?
Step 3: Add-on therapy
- Trial long acting beta 2 agonist (LABA): Salmeterol 50mcg/12h
- If no response to LABA: stop LABA and increase inhaled steroid dose to 800mcg/day
- If some, but inadequate, response to LABA: increase inhaled steroid dose to 800mcg/day. And if still inadequate response consider alternative add-on therapy:
1. Leukotriene receptor antagonist (first choice add-on therapy in children)
2. Theophyllines
3. Slow release beta 2 agonist tablets
What is step 4 of chronic asthma management?
Step 4: Additon of a 4th drug
- If control remains inadequate, consider the following interventions:
- Increasing inhaled steroids to 2000 micrograms/day
- Adding 4th drug e.g. leukotriene receptor antagonist; theophylline; slow release β2 agonist tablets (caution in patients already on long-acting β2 agonists
What is step 5 of chronic asthma management?
Step 5: Oral steroids
- Add regular oral prednisolone (at lowest dose for symptom control)
- Monitor for systemic side effects: BP, blood glucose, bone mineral density, cholesterol
- Continue high dose inhaled steroid
- Refer to specialist asthma clinic
What can good asthma control be defined as:
- No daytime symptoms
- No night-time awakening due to asthma
- No need for rescue medication
- No exacerbations
- No limitations on activity including exercise
- Normal lung function (in practical terms FEV1 and/or PEF > 80% predicted or best)
- Minimal side effects from medication
What are the complications of asthma?
- Pneumonia
- Lobar collapse
- Pneumothorax
- Respiratory failure
- Side effects from treatment - Hypokalaemia, arrhythmias
- Fatigue
- Psychosocial problems: depression, difficulties at work
What are markers of poorer prognosis in asthma?
- Poor adherence
- Previous acute admissions and/or intubation
- 3+ different classes of asthma medication
- psychosocial dysfunction
- Inadequately treated disease
- Smoking
What are the NICE guidelines for the management of asthma?
- Add short-acting beta 2 agonist inhaler (e.g. salbutamol) as required for infrequent wheezy episodes.
- Add a regular low dose inhaled corticosteroid.
- Add an oral leukotriene receptor antagonist (i.e. montelukast).
- Add LABA inhaler (e.g. salmeterol). Continue the LABA only if the patient has a good response.
- . Consider changing to a maintenance and reliever therapy (MART) regime.
- Increase the inhaled corticosteroid to a “moderate dose”.
- Consider increasing the inhaled corticosteroid dose to “high dose” or oral theophylline or an inhaled LAMA (e.g. tiotropium).
- Refer to a specialist.
What are the BTS/SIGN guidelines for the management of asthma?
- Add short-acting beta 2 agonist inhaler (e.g. salbutamol) as required for infrequent wheezy episodes.
- Add a regular low dose corticosteroid inhaler.
- Add LABA inhaler (e.g. salmeterol). Continue the LABA only if the patient has a good response.
- Consider a trial of an oral leukotriene receptor antagonist (i.e. montelukast), oral beta 2 agonist (i.e. oral salbutamol), oral theophylline or an inhaled LAMA (i.e. tiotropium).
- Titrate inhaled corticosteroid up to “high dose”. Combine additional treatments from step 4. Refer to specialist.
- Add oral steroids at the lowest dose possible to achieve good control.