Acute Wheeze or Asthma in Paediatrics
Introduction
Assessment and management should begin at referral to ensure safe transfer to DGRI especially if referred by a rural GP (and consideration given to an ambulance transfer).
Categorisation of children with asthma can help optimise their treatment and they should be assessed on their most severe symptom. Children should receive adequate assessment and treatment in A&E to ensure they are safely transported to the Children’s ward. Any child whose observations categorise their exacerbation as severe should be discussed with the on call paediatric registrar for consideration of review and initiation of treatment in the emergency department.
Children < 2 years old – assessment of severity
MODERATE SpO2 ≥ 92% Still feeding Using Accessory Muscles Audible wheezing | SEVERE SpO2 <92% Too breathless to feed Marked respiratory Distress | LIFE THREATENING SpO2 ≤ 92% plus any of: – Apnoea – Cyanosis – Poor respiratory effort – Bradycardia |
- Under 1 year of age consider alternate diagnosis such as Bronchiolitis where bronchodilators may not be indicated. (see Bronchiolitis Guideline)
- Most infants have recession with audible wheeze but are not distressed
- MDI + facemask / spacer is as effective as, if not better than, nebulisers for treating mild to moderate asthma in children < 2 years old
Wheeze flow chart – Children Aged <2
Assessment and management >2yrs of age.
- Yellow zone on PEWs = score of 1
- Red zone on PEWs = score of 3
Medication for acute wheeze
Nebulised medication for Severe Wheeze
2 – 4 years Salbutamol 2.5mg
Ipratropium bromide 250micrograms
Magnesium sulphate 150mg (50% ampoule for nebulisation =0.3ml)
>5 years Salbutamol 5mg
Ipratropium bromide 250micrograms (>12 years 500micrograms)
Magnesium sulphate 150mg (50% ampoule for nebulisation = 0.3ml)
To populate via HEPMA select Add Drug > Protocol>Acute Wheeze
Prednisolone
< 2 years old 10mg OD
2 – 4 years old 20mg OD
> 5 years old 40mg OD
If a child is already on daily steroids increase the dose to 2mg/kg (maximum 60mg).
Prescribing Prednisolone for patients being admitted to the wards:
- If 1st dose given between 8am and midnight, prescribe the 2nd dose for 8am the following morning
- If 1st dose given between midnight and 8am, the next dose should be prescribed at 2pm the same day, to ensure that the second dose is given within 24 hours of the first dose.
IV Hydrocortisone
Given if oral steroids not indicated
2 – 5 years 50mg QDS
5 – 16 years 100mg QDS
Escalation to IV therapy
- Have they failed to show any improvement or deteriorated since their presentation (considering severity at presentation)?
- Do they have a significant or increasing oxygen requirement?
A small decrease in oxygen saturation is common after initial bronchodilator therapy and should be taken in the context of clinical condition and response to treatment - Do they have increased work of breathing (severe or life threatening?)
- Do they have significantly reduced air entry or silent chest?
- Are there clinical signs of exhaustion?
- IV Magnesium sulphate (1st or 2nd line)
- 40mg/kg or 0.16 mmol/kg (max. 2 grams)
- Draw up 0.08ml/kg 50% Magnesium sulphate (40mg/kg) and dilute to 50ml with 0.9% NaCl. Run over 20-30 minutes.
- Assess response: If response to IV magnesium sulphate is felt to be poor or moderate, then progress to 2nd line – Aminophylline. Ensure that clinical parameters and relevant examination findings are documented.
- 40mg/kg or 0.16 mmol/kg (max. 2 grams)
- IV Aminophylline Loading dose (do not give if on long term theophylline)(1st or 2nd line)
- 5mg/kg (5ml/kg of 1mg/ml solution)
- Add 20ml of aminophylline 25mg/ml to 480ml of 0.9% sodium chloride to give a concentration of 1mg/ml. Run over 20 minutes.
- 5mg/kg (5ml/kg of 1mg/ml solution)
- IV Aminophylline maintenance dose (1st or 2nd line)
- Age 2 – < 12 years: 1mg/kg/hr = 1ml/kg/hr
- Age 12 years or above: 0.5mg/kg/hr = 0.5mls/kg/hr
- IV Salbutamol (3rd line AND Only used after discussion with PICU)
- Loading dose:
- 2 years: 15 micrograms/kg (maximum 250 micrograms) slow injection over 5 – 10 minutes.
- < 2 years: 5 micrograms/kg
- Infusion dose: 1 – 5 micrograms/kg/min.
- Loading dose:
Monitoring requirements
- Continuous ECG and saturation monitoring is necessary for patients on aminophylline and/or salbutamol infusions
- CBG / VBG repeated as clinically indicated
- Check aminophylline levels 1 hour after starting the maintenance infusion in all patients.
- All patients on long term Theophylline treatment should have levels checked prior to starting Aminophylline infusion as toxic levels can occur. Decisions on treatment can be made when levels are available.
Aminophylline Dose Adjustment Guidance
Poor response but no concern about toxicity:
Concern patient demonstrating signs of TOXICITY including:
- Muscle tremors
- Tachycardia and palpitations
- Nausea and vomiting
- Agitation
- High doses can cause peripheral vasodilatation which can result in hypotension.
Further Management
- If requiring IV fluids: 0.9% sodium chloride 5% dextrose with 10mmol KCL per 500mg bag
- Most exacerbations are viral and therefore do not require antibiotics or a CXR. These should only be considered if there are unilateral signs or a poor response to management. Viral throat swabs may be considered.
- A 3 day course of oral steroids is sufficient in most cases
- IV medication should be weaned before nebulisers or MDIs
- When de-escalating IV therapy, initially half the aminophylline infusion and review after 6 hours as rebound symptoms can occur
- Patients should be observed in hospital for at least 24 hours following de-escalation of therapy
- Consider switching from nebulisers to MDIs if not requiring oxygen
Discharge
- If comfortable on 3-4 hourly MDIs and not requiring oxygen for 12-24 hours the child can be considered for discharge
- Children should all receive a written asthma or wheeze plan to take home
- Inhaler technique should be checked in all children prior to discharge
- Patients should all be advised to see their GP in 1 week for review
- General paediatric or respiratory follow up should be considered in all children requiring IV therapy, and in those who have had 2 or more hospital admissions with wheeze
- Consider prescribing preventor therapy in patients who experience interval symptoms
- Follow up plans should be documented in the medical notes prior to discharge