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.
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.
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:
History taking should include specific information on:
All health professionals have a role in advocating for their patients by advising parents about the increased risk of wheezing associated with parental smoking.
Wheeze may be absent in severe cases due to severe airway obstruction or extreme fatigue. A “silent chest” (chest with little or no breath sounds) is a warning sign of life-threatening respiratory failure and/or respiratory arrest.
The clinical assessment of an asthmatic child should include:
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.
| Mild | Moderate | Severe | Life-threatening |
|---|---|---|---|
| Normal conscious state | Normal conscious state | Agitated Restlessness Distressed | Exhaustion Confused Altered level of consciousness |
| No accessory muscle use | Minimal accessory muscle use | Moderate muscle use Nasal flaring Tracheal tug Hyperinflated chest | Excessive muscle use Nasal flaring Tracheal tug Hyperinflated chest |
| Normal to a mild increase in respiratory rate | Tachypnoea | Tachypnoea Dyspnoea Prolonged expiration | Decreasing respiratory rate May only gasp occasionally |
| Normal pulse | Tachycardia | Tachycardia | Decreasing heart rate Pulse may be hard to feel |
| Talks in sentences | Talks in phrases | Talks in 1 – 2-word gasps | Unable to talk |
| No central cyanosis | No central cyanosis | Cyanosis likely | Cyanosis |
| SpO2 more than 94% | SpO2 90 – 94% | SpO2 less than 90% | SpO2 less than 90% |
| Pulsus paradoxus not present | Pulsus paradoxus may be palpable | Pulsus paradoxus palpable | Pulsus paradoxus palpable |
Adapted from: National Asthma Council Australia1 and Department of Health and Ageing, Australian Government 5
Alternative conditions which can present with clinical features similar to acute asthma include:
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.
For the management of wheeze symptoms in pre-school children refer to the Pre-school wheeze guideline.
Refer to the flowchart [PDF 534.88 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
Frequent repeated clinical assessment is the best indicator to guide management.
Salbutamol may be effectively administered by metered dose inhaler (MDI) with a spacer device or nebuliser.
| Inhaled salbutamol dosing for the treatment of asthma in children | |
|---|---|
| Metered dose inhaler (MDI)* 100 micrograms (spacer recommended) | Age 5 years: 6 puffs Age 6 years or more: 12 puffs |
| Nebulised | Age 5 years: 2.5 mg Age 6 years or more: 5 mg |
| Salbutamol burst | Administer three doses as above at twenty-minute intervals |
| Continuous nebulised salbutamol |
Neat salbutamol nebuliser solution (5 mg/mL), replenish where reservoir empty. Use 5 mg/1 mL nebules or 30 mL multi-use bottle. |
*Use mask also if unable to form a reliable seal on spacer
Stretching the time between salbutamol doses should be based on an assessment of the child. This should be done in collaboration with the child and caregiver and include:
Cumulative doses of Salbutamol can cause agitation, tremor, tachycardia, tachypnoea and rarely, hypertension. Raised lactate, hypokalaemia and raised glucose on VBG are markers of Salbutamol toxicity. Employ Salbutamol sparing measures of other listed medications/adjuncts to assist reducing salbutamol dosing.
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
| Ipratropium dosing for the treatment of asthma in children | |
|---|---|
| 5 years | 4 puffs (84 micrograms) via spacer OR 250 micrograms nebulised every twenty minutes for three doses. Can be mixed in nebuliser with Salbutamol. Followed by 2 puffs (42 micrograms) every six hours |
| Greater than 6 years | 8 puffs (168 micrograms) via spacer OR 500 micrograms nebulized every twenty minutes for three doses. Can be mixed in nebuliser with Salbutamol. Followed by 4 puffs (84 micrograms) every six hours |
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).
| Steroid dosing for the treatment of asthma in children | |
|---|---|
| Dexamethasone (oral/IM/IV) | Single dose on day 1 of 0.6mg/kg (maximum 16mg)1 Dexamethasone 0.5mg and 4mg tablets are available but they are not easily dispersed in water to give in a partial dose. Doses that can be rounded to full tablet size can however be crushed and dispersed in water.28 Dexamethasone injection can be given orally and is tasteless. If IV stock is in shortage, please give liquid suspension. |
| Prednisolone (oral) | Day 1: 2 mg/kg (maximum 50 mg) Day 2 and 3: 1 mg/kg Can extend course to five days if still symptomatic after three-day course |
| Hydrocortisone (IV) | 4 mg/kg (maximum 100 mg) then every six hours on day one |
| OR Methylprednisolone (IV) | 1 mg/kg (maximum 60 mg) then every six hours on day one |
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
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
| Magnesium sulphate (IV) dosing for the treatment of asthma in children | |
|---|---|
| Bolus dose | 0.2 mmol/kg (equivalent to 50 mg/kg) infused intravenously over twenty minutes (maximum 10 mmol = equivalent to 2,500 mg). Doses up to 0.4 mmol/kg (maximum of 10 mmol) have been used. Must be administered in syringe driver using safety software. |
| Side effects | Usually minor, including epigastric or facial warmth and flushing, pain and/or numbness at infusion site and dry mouth. Severe reactions include allergy, hypotension, respiratory depression and circulatory collapse. Their incidence increases with infusions <20 minutes. |
| Monitoring | Full cardiac monitoring with blood pressure every five minutes. Cease infusion if hypotension persists. Monitor knee reflexes if repeating dose to assess for magnesium toxicity which can result in respiratory failure. Cease magnesium if reflexes absent. |
Magnesium sulphate should always be prescribed in mmols and administered using safety software syringe drivers to avoid medication errors.
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.
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.
| Adrenaline dosing for the treatment of asthma in children | |
|---|---|
| Adrenaline (IM) | 0.01 mg/kg (max. 0.5 mg) ~ 0.01 mL/kg of 1:1000 solution (undiluted) Repeat as necessary every 5 minutes |
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
| Salbutamol (IV) dosing for the treatment of asthma in children28-36 | |
|---|---|
| Bolus dose | 15 microg/kg infused over ten minutes (maximum 300 micrograms) |
| Infusion | 0.5 – 1 microgram/kg/min (maximum 40 micrograms a min). Higher dosages may be required under the direction of the PMC or Intensivist. |
| Side effects | Cumulative doses of salbutamol can cause agitation, tremor, tachycardia, tachypnoea and rarely, hypertension. Raised lactate, hypokalaemia and raised glucose on VBG are markers of salbutamol toxicity. |
| Monitoring |
Full cardiac monitoring. Monitor venous potassium levels. |
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.
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:
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 739.94 KB].
Contact paediatric critical care specialists (onsite or via RSQ) if considering intubation and ventilation.
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.
| Includes children with the following (as a guide): | |
|---|---|
| |
| 5-11 years | Over 12 years |
|
|
| Reason for contact | Who to contact |
|---|---|
| For immediate onsite assistance including airway management | The most senior resources available onsite at the time as per local practices. Options may include:
|
| Paediatric critical care advice and assistance | Onsite or via Retrieval Services Queensland (RSQ). If no onsite paediatric critical care service contact RSQ on 1300 799 127:
RSQ (access via QH intranet) Notify early of child potentially requiring transfer. Consider early involvement of local paediatric/critical care service. In the event of retrieval, inform your local paediatric service. |
| May include children with: |
|---|
|
| Reason for contact | Who to contact |
|---|---|
| Advice (including management, disposition or follow-up) | Follow local practices. Options:
|
| Referral | First point of call is the onsite/local paediatric service |
| Do I need a critical transfer? |
|
| Request a non-critical inter-hospital transfer |
|
| Non-critical transfer forms |
|
Consider discharge for a child who has ALL of the following:
Consider a longer period of observation despite meeting the clinical discharge criteria for the following children:
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.
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:
On discharge a child should be provided with:
Consider admission for the following children:
Consider a longer period of observation despite meeting the clinical discharge criteria for the following children:
Consider admission to an EDSTTA if:
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:
Local practices will dictate criteria for admission from EDSTTA to an inpatient ward. Some general criteria to consider include: