Asthma Flashcards
Asthma is the leading chronic condition in children in developed countries. It is characterised by reversible airway obstruction. What is the presentation of asthma in children?
- Cough
- Dyspnoea
- Widespread wheeze
- Chest tightness
What are the risk factors for asthma?
- Frequent wheeze during the first 3 years of life
- Family hx of asthma
- Hx of atopy (allergy, eczema)
- Exposure to tobacco smoke
- Exposure to pollution
- Obesity
- Reduced birth weight
- Bottle fed
What are the triggers for asthma?
- Pollen
- House dust mite
- Feathers / fur
- Exercise
- Viruses
- Chemicals
- Smoke
- Traffic
How is asthma diagnosed?
Through serial peak flow readings, both when symptomatic and asymptomatic because the airflow obstruction is reversible.
Treatment for children & young people aged 5-16 with asthma
- Newly diagnosed asthma:
=> Short-acting beta agonist i.e. salbutamol - Not controlled on previous step or newly diagnosed asthma with >3 symptom/ week or night-time waking:
=> SABA + paediatric low dose inhaled corticosteroids - SABA + paediatric low dose inhaled corticosteroids + leukotriene receptor antagonist (LTRA)
- SABA + paediatric low dose inhaled corticosteroids + LABA
* stop LRTA - SABA + switch ICS/LABA for a maintenance and reliever therapy (MART) that includes a paediatric low-dose ICS
- SABA + paediatric moderate-dose ICS MART
OR consider changing back to a fixed dose of a moderate-dose ICS and a separate LABA
- SABA + one of the options:
=> increase ICS to paediatric high dose, either as part of a fixed dose regime or as MART
=> a trial of additional drug e.g. theophylline
=> seeking advice from asthma specialist
Asthma management in children under 5 years of age
- Newly diagnosed asthma: SABA
- Not controlled on previous step OR newly diagnosed asthma with symptoms >3/week or night time waking:
- SABA + 8 week trial of paediatric MODERATE-dose inhaled corticosteroids (ICS)
After 8 weeks stop ICS and monitor symptoms:
=> if symptoms don’t resolve, review for alternative diagnosis
=> if symptoms resolved then reoccured within 4 weeks of stopping ICS , restart ICS at a paediatric LOW dose as first line maintenance therapy
=> if symptoms resolved but reoccured beyond 4 weeks after stopping ICS treatment, repeat the 8 week trial of a paediatric MODERATE dose of ICS
- SABA + paediatric low dose ICS + leukotriene receptor antagonist (LTRA)
- Stop LTRA and refer to paeds asthma specialist
What is a maintenance and reliever therapy (MART)?
MART = combined ICS and fast acting LABA treatment in a single inhaler, which is used for both daily maintenance therapy and the relief of symptoms as required
*MART is only available for ICS and LABA in which LABA has a fast-acting component i.e. formoterol, not salmeterol
What is the general management of asthma?
- Annual review of symptoms
- Exacerbations
- Oral steroid use
- Time off school
- Check inhaler technique
- Medication adherence
- Make a personalised self-management action plan
- Advice regarding tobacco smoke exposure
- Record height and weight on centile chart
What are the differentials for asthma in children?
- Croup
- Foreign body
- Pertussis
- Pneumonia / TB (do CXR!!)
- Hyperventilation
- Aspiration
- Cystic fibrosis (wet cough, starting at birth, failure to thrive)
Severity of acute asthma exacerbation definitions:
- Near-fatal / life-threatening:
=> Respiratory acidosis and/or requiring mechanical ventilation with increased ventilation pressures
=> Any of the following: PEFR <33% predicated, sats <92%, silent chest, cyanosis, feeble respiratory effort, bradycardia, dysrhythmia, hypotension, exhaustion, confusion, coma
- Acute severe:
=> PEFR 33-50% predicated
=> Respiratory rate:
2-5 years >40/min
5-12 years >30/min
>12 years >25/min
=> Pulse:
2-5 years >140bpm
5-12 years >125bpm
>12 years >110bpm
=> Inability to complete sentences; use of accessory muscles
- Moderate exacerbations:
=> Increasing symptoms
=> PEFR 50-70% best or predicted
=> No features of severe asthma - Brittle asthma:
=> Type 1: wide variability in PEFR despite intensive therapy
=> Type 2: sudden severe attacks despite apparently well controlled asthma
What causes acute exacerbations of asthma in children?
Triggered by exposure to allergens i.e. dust, pollution, animal hair or smoke causing IgE type 1 hypersensitivity reaction, leading to smooth muscle contraction, bronchial oedema and mucus plugging.
How does acute severe asthma attack present?
Fast onset breathlessness, widespread wheeze and chest tightness - exacerbations developing over minutes to hours. => confirmed by reduced peak expiratory flow rate and FEV1 which improves with treatment
Wheeze may be audible at bedside or heard bilaterally on auscultation
*refer back to signs on acute severe episode and life threatening episode covered in different flashcard
What are the differentials for acute asthma attack in children?
1. Pneumothorax => Very sudden onset => Assoc. chest pain => Possible trachea deviation => unilateral chest signs
- Anaphylaxis:
=> Very sudden onset
=> Assoc. with antigen exposure - Inhalation of foreign body:
=> unilateral chest signs - Cardiac arrhythmia:
=> chest pain / palpitations
=> tachycardia
=> changes in blood pressure
How is acute asthma managed in children in hospital?
- Inhaled salbutamol
- Nebulised salbutamol
- Add nebuliser ipratropium bromide
- If sats <92%, add magnesium sulphate
- Oral or IV steroids
- Add IV salbutamol if no response to inhaled therapy
- If severe or life threatening acute asthma not responsive to inhaled therapy, add Aminiphylline
O2 sats maintained between 94-98% with high flow oxygen if necessary.
How do you treat severe asthma with life threatening signs or if no improvement after 15-30 mins treatment initiation?
- Sit up, high flow 100% O2
- Salbutamol: 5mg O2 nebulised in 4mL saline (2.5mg if <5yrs) with ipratropium bromide 0.25mg
- Hydrocortisone 100mg IV or prednisolone soluble tablets 1-2mg/kg to max 40mg (60mg if already on steroids and under 12yrs), 50mg >12yr
- Consider one IV dose of magnesium sulphate 40mg/kg over 20 mins (<2g)
- Aminophylline: 5mg/kg IV over 20 min (give with ondansetron - prevents vomiting)
- Nebulisers continuously until improving, then at 30 mins interval reducing frequency once improving. Give ipratropium 8-hrly if need
- Consider starting CPAP in ED. Take to ITU if exhausted, confused, coma or refractory to treatment and needing IVI salbutamol.
