Asthma – Emergency management in children

Purpose

This document provides clinical guidance for all staff involved in the care and management of a child presenting to an Emergency Department (ED) with asthma symptoms in Queensland. The management of children aged one to five years who present with a wheezing illness is outlined in the Pre-school wheeze – Emergency management in children guideline.

This guideline has been developed by senior ED clinicians across Queensland, with input from Paediatric Respiratory specialists, Queensland Children’s Hospital, Brisbane. It has been endorsed for use across Queensland by the Queensland Emergency Care of Children Working Group in partnership with the Queensland Emergency Department Strategic Advisory Panel and the Healthcare Improvement Unit, Clinical Excellence Queensland.

Introduction

Asthma is a chronic inflammatory disorder of the airways involving reversible airway obstruction. It is estimated to affect one in six Australian children.¹ Asthma is one of the most common paediatric ED presentations.

Children with asthma have sensitive airways which react to triggers (such as viral illnesses) causing - airway inflammation, thickened mucous and bronchospasm leading to a narrowing of the airways, reduced airflow and air trapping.³ Children with acute asthma usually present with cough, wheeze and/or difficulty breathing. In an acute asthma episode, a wheeze may not always be heard but a prolonged respiratory phase of expiration may be present. Acute bronchospasm may lead to respiratory failure and life-threatening acute asthma if not identified and treated promptly.^3,4 The diagnosis of asthma is confirmed by demonstrating reversible airway obstruction. Other diagnoses can also cause recurrent respiratory symptoms.

Assessment

Children with asthma may present with a range of symptoms and varying levels of severity. Initial assessment should be within the time frame recommended by the patient’s triage (ATS) category. The child’s general appearance or mental state and level of respiratory distress are the most important markers of severity.

The aim of the initial assessment is to:

• confirm an asthma episode
• identify symptom pattern, severity and possible trigger factors
• look for features suggestive of an alternative diagnosis or associated condition

History

History taking should include specific information on:

• signs and symptoms (including wheeze, cough and respiratory distress) and management to date for the current episode
• history of previous wheezing episodes (including severity, previous management and hospitalisations, including PICU admission) and previous asthma diagnosis
• symptoms present between episodes including inability to keep up with other children
• regular asthma management plan (if any)
• personal history of hayfever and management
• family history (including mother and sibling/s) of asthma and atopy
• smoking history of household members

All health professionals have a role in advocating for their patients by advising parents about the increased risk of wheezing associated with parental smoking.

Examination

The clinical assessment of an asthmatic child should include:

• respiratory rate and phases of respiration
• work of breathing and use of accessory muscles (nasal flaring, tracheal tug, intercostal or substernal recession)
• oxygen saturation (in room air or with supplemental oxygen)
• heart rate
• skin colour (pallor or cyanosis)
• blood pressure and pulse volume
• level of consciousness (irritability or drowsiness)

The modified version of the National Asthma Council Australia severity assessment criteria and the Australasian Triage Scale (ATS) is displayed in the table below.

Seek senior emergency/paediatric assistance as per local escalation practices for a child with severe or life-threatening asthma. Consider contacting paediatric critical care specialists (onsite or via Retrieval Services Queensland (RSQ)) for life-threatening cases.

Initial assessment of acute asthma in children

Adapted from: National Asthma Council Australia¹ and Department of Health and Ageing, Australian Government ⁵

Differential diagnosis

Alternative conditions which can present with clinical features similar to acute asthma include:

• anaphylaxis - can masquerade as a severe asthma presentation
• inhaled foreign body
• gastro-oesophageal reflux
• diabetic ketoacidosis
• pneumonia
• croup

Investigations

Investigations are not routinely recommended in the initial management of acute asthma.⁵ They may be considered in a child with life-threatening asthma or severe asthma who is not responding to treatment, or where alternate or concurrent diagnoses are being considered.⁵

Venous blood gas will allow monitoring of venous carbon dioxide, and serum potassium, lactate and glucose as markers of potential Salbutamol toxicity. CXR may assist if considering either alternate diagnosis or to exclude complications of acute asthma such as collapse or pneumothorax.

Management

For the management of wheeze symptoms in pre-school children refer to the Pre-school wheeze guideline.

Refer to the flowchart [PDF 530.46 KB] for a summary of the recommended emergency management of children with asthma.

The initial management of acute asthma in children comprises of inhaled beta2-agonists (Salbutamol) inhaled anticholinergics (Ipratropium Bromide) - and steroids while maintaining adequate oxygenation.^3,6 Other useful adjuncts for more severe episodes or escalation of treatment may include Magnesium sulphate IV, Salbutamol IV, Aminophylline IV and Adrenaline IM.^3,6

Inhaled salbutamol

Salbutamol may be effectively administered by metered dose inhaler (MDI) with a spacer device or nebuliser.

*Use mask also if unable to form a reliable seal on spacer

MDI and spacer vs nebuliser

• MDI is preferred as faster (nebulisation requires a child to sit still for at least 10 minutes) and more efficient.
• Delivery of salbutamol by nebuliser results in greater facial and oropharyngeal deposition of medication delivering at best 10% of the prescribed drug to the lungs, with consequent systemic absorption and side effects such as tachycardia and tremor.
• Children who are struggling with their breathing and who are not able to co-ordinate taking a deep breath through the spacer should be given nebulised medication.

How to use a spacer

• Some spacers require priming, see packaging details. Prime spacer before use to negate electrostatic charge (and optimise drug delivery) with 10 puffs of Salbutamol.
• Shake MDI before each puff.
• Administer one puff at a time into the spacer.
• The medication is cleared from the spacer by the child taking four tidal breaths following each puff of medication or taking one large breath and holding. If the child is unable to form a reliable seal around the spacer, a mask should be used.

Ipratropium bromide (Atrovent)

Ipratropium bromide may be useful in combination with Salbutamol in the early management of children presenting with moderate to severe acute asthma.^1,5 The mechanism of action of anticholinergic bronchodilators remains unclear. However, it is thought that cholinergic pathways play an important role in the pathogenesis of asthma exacerbations.¹¹

There is good evidence to suggest that combined Ipratropium bromide and Salbutamol therapy is superior to Salbutamol therapy alone.^12-15 It has been demonstrated that combined therapy given in the first two hours (ideally combining Ipratropium bromide with the first three Salbutamol doses) is safe and results in  a significant improvement in the peak expiratory flow rate, ultimately decreasing hospitalisation rates.¹⁶ Ipratropium bromide has been shown to be of benefit in children that have not responded to inhaled Salbutamol alone.⁵

Steroids

Corticosteroids are recommended to treat the airway oedema and increased mucous production in a child with a moderate-to-severe acute asthma episode, or with persistent symptoms following Salbutamol.^7,8 A Cochrane review reported that hospital admission rates for children with acute asthma were significantly reduced for those who received corticosteroids within one hour of ED presentation.⁹ Oral corticosteroid treatment is particularly effective in children and has minimal side effects.⁹ Maximum benefit occurs within four to six hours after administration. Dexamethasone is non inferior to prednisolone³⁸ has the advantage of being a single dosage eliminating the need for scripts and steroids on discharge.

For pre-school children, particularly those with intermittent viral induced wheezing, corticosteroids should be limited to those with at least moderate but generally severe acute wheeze requiring hospital admission (see Pre-school wheeze guideline).

While there is some evidence for the benefit of inhaled corticosteroids and leukotriene receptor antagonists in acute asthma, oral or intravenous corticosteroids remain the current treatment of choice.¹⁰

Magnesium sulphate

Seek senior emergency/paediatric advice as per local practices for a child requiring Magnesium sulphate. Consider seeking paediatric critical care input (onsite or via RSQ).

Consider magnesium sulphate IV for children with severe acute asthma who are not responding to conventional bronchodilators used in the first hour.¹⁷ A meta-analysis on the use of magnesium sulphate IV in acute to moderate to severe asthma in ED found benefits in pulmonary function tests and hospitalisation rates.¹⁸

The action of Magnesium sulphate remains unclear. It is thought that magnesium ions decrease the uptake of calcium by bronchial smooth muscle cells, which leads to bronchodilation.^18,19 It may also have a role in inhibiting mast cell degranulation, which reduces inflammatory mediators.^18,19

Administer magnesium sulphate using safety software syringe drivers with a standard concentration of 0.5 mmol/ml. e.g. if patient weighs 10 kg, the magnesium sulphate dose is 0.2 mmol/kg = 2 mmol. This translates to 4 mL of 0.5 mmol/mL solution and must be administered through a safety software syringe driver over 20 minutes to minimise the risk of too rapid administration and dosing errors.

Currently, there is no good evidence to support using inhaled Magnesium sulphate as an alternative to inhaled beta2-agonists.^17,20 A preservative free preparation of magnesium sulphate suitable for nebuliser therapy is currently unavailable in Queensland.

Intramuscular Adrenaline

Contact paediatric critical care specialists (onsite or via RSQ) for children requiring Adrenaline IM

In life threatening asthma, consideration should be given for the role of intramuscular adrenaline especially if there is a history of anaphylaxis. Severe bronchoconstriction will limit Salbutamol efficacy via the inhalation route.

Intravenous salbutamol

Contact paediatric critical care specialists (onsite or via RSQ) for children requiring salbutamol IV.

Salbutamol IV should be considered for children who present with severe or life-threatening acute asthma and who do not respond appropriately to initial continuous doses of inhaled beta2-agonists. The near or complete airway obstruction that can occur in life-threatening asthma can prevent effective aerosolised bronchodilator therapy.²¹

A single bolus dose of salbutamol IV can be given as a standalone dose or can be given prior to commencing an infusion. A single bolus of salbutamol IV administered over 10-20 minutes has been shown to shorten the duration of severe asthma attacks, improve recovery time and reduce the overall requirements for inhaled salbutamol.^21-23

The approach to salbutamol IV dose can vary between starting at the lower or higher end and adjusting according to response. Concerns have been expressed that the current recommendations for children may be excessive and may unnecessarily raise the potential for adverse reactions such as lactic acidosis and tachycardia, and through increasing respiratory workload, exacerbate respiratory fatigue.²⁴

The current recommended dosing practice is to use a higher rate initially and reduce thereafter.^25-27

Aminophylline

Contact paediatric critical care specialists (onsite or via RSQ) prior to administering aminophylline IV.

Traditionally, Aminophylline IV has been used in children with severe asthma who are unresponsive to maximum doses of bronchodilators and steroids in the critical care setting. Aminophylline improves lung function within six hours of treatment, however there is limited improvement in symptoms, and no reduction in duration of hospital admission.²⁸ It is also associated with numerous side effects including vomiting.⁵ Aminophylline should not be given as an intravenous infusion in the patient already taking oral Theophylline. Please see CREDD for dosing.

High flow nasal cannula (HFNC) therapy and non-invasive ventilation (NIV)

Seek urgent paediatric critical care advice (onsite or via RSQ) if commencing HFNC therapy or NIV.

NIV and HFNC therapy are usually well tolerated in children with acute respiratory insufficiency due to asthma who have not responded to standard medical therapies. Early use may prevent the requirement for intubation and mechanical ventilation.^29,30

Consider HFNC therapy, CPAP or BiPAP for a child who:

• is unable to maintain SpO2 greater than 90% despite high flow oxygen via a non-rebreather mask
• has deteriorating work of breathing with increasing fatigue, tachycardia, and tachypnoea
• Nebulised salbutamol can be delivered through some circuits (900PT562)

NIV requires 1:1 nursing in a child with an altered level of consciousness. HFNC therapy may be valuable to provide pre-oxygenation while preparation for intubation is underway in children with a deteriorating level of consciouness.²⁵

Potential concerns (PDF) (access via QH intranet) have been raised regarding the use of HFNC therapy.

Follow local policies and procedures for nursing ratios and ward location. View CHQ Nasal high flow therapy guideline [PDF 583.46 KB].

Contact paediatric critical care specialists (onsite or via RSQ) if considering intubation and ventilation.

Escalation and advice outside of ED

Clinicians can contact the services below if escalation of care outside of senior clinicians within the ED is needed, as per local practices. Transfer is recommended if the child requires a higher level of care.

Critically unwell or rapidly deteriorating child

Non-critical child

Inter-hospital transfers

Disposition

When to consider discharge from ED

Consider discharge for a child who has ALL of the following:

• maintain SpO2 ≥ 90% in room air
• not tachypnoeic
• no/mild work of breathing
• good air entry with minimal wheeze
• clinically stable not requiring bronchodilator therapy more frequently than every three hours
• has a parent/caregiver who can safely manage the child at home, return in event of deterioration and access further medication

Consider a longer period of observation despite meeting the clinical discharge criteria for the following children:

• previous critical care admission or previous sudden deterioration
• unable to get to a hospital within 30 minutes
• social factors impacting upon ability to monitor and supervise child at home

An assessment of the family’s ability to safely manage the child at home should be done as per the Asthma Disease Education Checklist [PDF] for all children with asthma prior to discharge.

Preventer Inhalers

Patients presenting to emergency with asthma flares may benefit from 4-6 week trial of a preventer if they have had several acute wheezy episodes in the previous 12 months. Consider introducing a preventer inhaler, such as Fluticasone, if any of the following criteria are met:

• More than one exacerbation requiring admission (including STTA) every 6 weeks or more than 6 exacerbations per year
• Symptoms which occur once per week and disrupt child’s sleeping or play
• Asthma exacerbation requiring medical or ICU admission
• Chronic cough thought to be related to asthma

On discharge a child should be provided with:

• Discharge letter
• Asthma Action Plan – copies for family, general practitioner, and medical record
• Asthma Factsheet
• Puffers and Spacers Factsheet
• Link to Asthma Educational Video

Follow-up

• With GP or Paediatrician within a week, if the illness was severe
• With GP or Paediatrician to review outcome of trial of preventer inhaler at 4-6 weeks.

When to consider admission

Facilities without a Short Stay Unit/ED Short Term Treatment Area (EDSTTA)

Consider admission for the following children:

• severe illness (defined as ongoing respiratory distress, failure to respond to initial treatment or requiring oxygen)
• unable to stretch bronchodilators within four hours of ED presentation

Consider a longer period of observation despite meeting the clinical discharge criteria for the following children:

• previous critical care admission or previous sudden deterioration
• unable to get to a hospital within 30 minutes
• social factors impacting upon ability to monitor and supervise child at home

Facilities with a Short Stay Unit (EDSTTA)

Consider admission to an EDSTTA if:

• symptoms occur within one to two hours of initial treatment with bronchodilator/steroids AND
• no further investigations are required

Children who require bronchodilator therapy more frequently than one hourly require vigilant monitoring and regular review by medical staff.²³ Unless specifically discussed with EDSTTA medical and nursing staff, the child should remain in the acute assessment area of the ED.

During admission to EDSTTA:

• vital signs and respiratory assessment should be recorded in line with bronchodilator frequency or hourly if requiring oxygen supplementation
• Salbutamol frequency can be weaned (“stretched”) by appropriately trained nursing or medical staff, depending on local practices

When to consider admission to inpatient ward from EDSTTA

Local practices will dictate criteria for admission from EDSTTA to an inpatient ward. Some general criteria to consider include:

• clinical deterioration with a need to escalate treatment
• failure to progress and wean bronchodilators to every three hours in 12 – 24 hours (consider poor bronchodilator response, suboptimal administration or alternative diagnosis)
• persisting supplemental oxygen requirement.

Related documents

Guideline

• Pre-school wheeze
• Management of Severe Acute and Life-Threatening Asthma in PICU (PDF) (QH only)

Forms and factsheets

• Asthma Disease Education Checklist (PDF) (QH only)
• Wheeze Action Plan
• Asthma Factsheet
• Puffers and Spacers Factsheet

Educational videos

• Asthma video series