This document provides clinical guidance for all staff involved in the care and management of children aged 1 to 5 years presenting to an Emergency Department (ED) in Queensland with a wheezing illness.
It has been developed by senior ED clinicians and Paediatricians across Queensland, with specialist input from Paediatric Respiratory staff, Lady Cilento Children’s Hospital, Brisbane. It has been endorsed for use across Queensland by the Statewide Emergency Care of Children Working Group in partnership with the Queensland Emergency Department Strategic Advisory Panel and the Healthcare Improvement Unit, Clinical Excellence Division.
Guidance for wheezing children aged less than 1 year can be found in the Bronchiolitis – Emergency management in children Guideline and Australasian Bronchiolitis Guideline. For wheezing children over 5 years refer to the Asthma – Emergency Management in Children Guideline.
Wheeze is a very common emergency department presentation in children that is usually caused by intercurrent viral infection or other environmental triggers.
Wheeze is a continuous high-pitched sound with musical quality emitting from the chest during expiration,1 with increased work of breathing.2 Pre-school wheeze is also commonly referred to as reactive airways disease.
Evidence suggests that up to 30% of children will have at least 1 episode of wheezing prior to their 3rd birthday,3,4 over half will have >1 episode 5 and 60% will stop wheezing by 6 years of age.
The pathology and natural progression of wheezing illnesses in pre-schoolers is variable and not fully understood. The clinical definitions for the temporal pattern of preschool wheeze that have been proposed by the 2008 European Respiratory Task Force (ERS) 1 to guide treatment are outlined in the table below.
|Episodic viral wheeze (EVW)
||Wheeze during discrete time periods, often in association with clinical evidence of a viral infection, with absence of wheeze between episodes
||Most common in preschool children
Usually associated with a viral respiratory tract infection e.g. rhinovirus, RSV, coronavirus, human metapneumovirus, parainfluenza virus and adenovirus.
Repeated episodes tend to occur seasonally
Usually declines over time disappearing by 6 years but can continue to school age and change into MTW or disappear
|Multi-trigger wheeze (MTW)
||Wheezing that shows discrete exacerbations but also symptoms between episodes
- viral infection (most common)
- tobacco smoke
- allergen exposure
Though it is thought that MTW reflects chronic allergic airway inflammation there is little evidence to support this. Pre-school wheeze should be described in terms of the temporal patterns (EVW and MTW), frequency, severity, age of onset and relevant associated clinical parameters such as atopy and eczema.6 Note that children may change between categories over time and in that event pharmacological treatment should also change.2
The term asthma is not used to describe pre-school wheezing illness as there is insufficient evidence that the pathophysiology of pre-school wheezing illness is similar to that of asthma in older children and adults.1
Risk factors for a future diagnosis of asthma include:
- onset of wheezing over the age of 18 months
- personal history of atopy e.g. eczema
- maternal asthma
Several clinical predictive indices for future risk of asthma have been developed based on combinations of the presence of atopic manifestations, indirect evidence of airway inflammation such as peripheral blood eosinophil count, and severity of pre-school wheeze.2 The clinical utility of such predictive indices is limited due to a poor ability to correctly identify those who will develop asthma (positive predictive value (PPV) ranging from 44 to 54%). However, the absence of known risk factors can be useful to reassure parents of a lower risk of future asthma.
The purpose of assessment (history taking and physical examination) is to:
- confirm a wheezing disorder
- identify symptom pattern, severity and possible trigger factors
- look for features suggestive of an alternative diagnosis or associated condition1
Studies have shown while physicians can accurately identify wheeze, parents may not be able to do so.2 Ideally, the presence of a wheeze should be confirmed by a clinician.
History should include specific information on:
- the wheeze, other noises and other signs (including respiratory distress)
- family history (including mother and sibling/s) of asthma and atopy
- smoking status 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.
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.7
|Can walk or move around
Speak in phrases
Sp02* >90% in room air (RA)
Mild respiratory distress#
|Unable to complete sentences in one breath due to dyspnoea
Sp02 <90% (RA)
Significant respiratory distress +/- grunting
|Altered conscious level/exhaustion
Poor respiratory effort/agonal breathing
Sp02 <90% (RA) +/- cyanosis
Soft or absent breath sounds
*Oxygen saturations using pulse oximetry (commonly referred to as “sats”.)
#Signs of respiratory distress include accessory muscle use, abdominal breathing, intercostal recession, subcoastal recession and tracheal tug
ALL the following
ANY of the following
ANY of the following
||Agitated, restless, distressed
||Drowsy or unconscious
|Can talk or vocalise
||Speech may be limited
||Unable to vocalise due to dyspnoea
|Can walk or crawl
||Collapsed or exhausted
|Mild-moderate respiratory distress
||Severe respiratory distress
||Severe respiratory distress or poor respiratory effort
|Normal skin colour
||Not applicable [NB2]
|Normal respiratory rate [NB3]
|Normal heart rate [NB4]
||Cardiac arrhythmia or bradycardia (preterminal sign, may occur just before respiratory arrest)
|Wheeze or normal lung sounds
||Not applicable [NB2]
||‘Silent chest’ or reduced air entry
||Sp02 <90% or clinical cyanosis
NB2: May be the same as mild–moderate and does not determine severity level.
NB3: Normal respiratory rate (breaths/min): younger than 1 year, 30 to 40; 1 to 2 years, 25 to 35; 2 to 5 years, 25 to 30.
NB4: Normal heart rate (beats/min): younger than 1 year, 110 to 160; 1 to 2 years, 100 to 150; 2 to 5 years, 95 to 140.
Source: Adapted from Therapeutic Guidelines and Asthma Handbook
Oxygenation (Sp02) is effectively measured in using pulse oximetry. Poor gas exchange and decreased saturations may be a result of severe airway obstruction due to bronchoconstriction, airway oedema and/or mucous plugging.8
Wheeze is due to narrowing of intrathoracic airways and expiratory flow, irrespective of the underlying mechanism. However, there are alternative and less common reasons for a child to wheeze. Consider further investigation if assessment (history and examination) identifies as any unusual features which may allude to the differential diagnoses outlined in the following Table.
||Anatomical abnormalities of the airway. e.g. tracheomalacia, bronchomalacia
Chronic suppurative lung disease/bronchiectasis including cystic fibrosis
||Inhaled foreign body
Refer to the flowchart for a summary of the recommended emergency management of pre-school wheeze.
The management of pre-school wheeze comprises of medications targeted at relieving acute bronchospasm, alleviating lower airways inflammation, and providing respiratory support in the form of oxygen and non-invasive ventilation. Medications to treat wheeze when associated with mild respiratory distress may not be necessary e.g. steroids, inhaled ipratropium bromide.2
There is a spectrum of clinical presentations of wheeze in young children, and patients may transition from one phenotype to another or have a mixed picture.1 Repeated clinical assessment is recommended following each treatment to objectively determine the change in clinical symptoms (improvement/no change/deterioration). This should be well documented in the patient clinical notes. Medications should be discontinued if there is no objective change.
A trial of short acting inhaled beta2 agonists (salbutamol, Ventolin) is recommended for all wheezing children between the ages of 12 months and 5 years.9 Continuous oximetry should be performed for children on salbutamol with a frequency < 2nd hourly. Bronchodilators may produce a paradoxical effect in children with underlying structural abnormalities such as bronchomalacia or tracheomalacia.10
|Inhaled salbutamol dosing for the treatment of wheeze in pre-school children
|MDI * 100mcg
||< 20 kg: 6 puffs
||> 20kg: 12 puffs
||< 20 kg: 2.5mg
||> 20kg: 5mg
||Administer 3 doses as above at 20-minute intervals
|Continuous nebulised salbutamol
||Neat salbutamol nebuliser solution (5mg/mL), replenish where reservoir empty
*Metered Dose Inhaler. Always use via spacer. Use mask also if unable to form a reliable seal on spacer
ALERT – 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.
MDI and spacer vs nebuliser
- Both modes of administration are equally effective for relieving bronchoconstriction.
- MDI is faster (nebulisation requires a child to sit still for at least 10 minutes).
- 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 not able to co-ordinate taking a deep breath through the spacer should be given nebulised medication.
How to use a spacer
- Prime spacer before use to negate electrostatic charge (and optimise drug delivery) with 10 puffs of salbutamol.
- Shake MDI before each puff.
- Administer 1 puff at a time into the spacer (with a face mask attached if required).
- The medication is cleared from the spacer by the child taking 5 breaths following each puff of medication.
Stretching the time between salbutamol doses should be based on an assessment on the child. This should be done in collaboration with the child and caregiver30 and include:
- respiratory distress: decreased work of breathing (subcostal & intercostal recession/ tracheal tug /nasal flaring)
- activity level: decreasing lethargy, increasing alertness
- respiratory rate: decreasing to within normal limits for age
- heart rate: decreasing to within normal limits for age. Note bronchodilator therapy increases heart rate.
- speech: able to talk in sentences
- auscultation: air entry improved, wheeze reduced or appearance of wheeze in previously quiet chest (note wheeze alone is not an indication for giving salbutamol)
- cough: reduction or change in cough i.e. becomes looser
- oxygen saturations: increasing oxygen saturations and decreasing oxygen requirement
Inhaled anticholinergic agents
There is insufficient evidence to support the routine use of anti-cholinergic therapy (ipratropium bromide) for children with pre-school wheeze.11 However, the ready availability of MDIs often prompts the use of ipratropium, and therefore doses have been included for reference.
Children with severe symptoms should be considered for up to 3 doses of ipratropium bromide. This should be given following salbutamol MDI or in combination with salbutamol in nebuliser reservoir.12
|Inhaled ipratropium dosing for the treatment of wheeze in pre-school children
|MDI * 20mcg
||< 20 kg: 4 puffs
||>20kg: 8 puffs
||< 20 kg: 250mcg
||Maximum of 3 doses in 24 hours
*Metered Dose Inhaler. Always use via spacer. Use mask also if unable to form a reliable seal on spacer.
Steroids are not recommended for pre-school aged children who present for the first time or infrequently with a mild to moderate wheeze however, the literature is constantly evolving. Some studies suggest that steroids do not reduce symptom severity or the need for hospital treatment in pre-school children with mild to moderate wheeze.8 A large randomised, double-blind, placebo-controlled trial found no significant difference in the duration of hospitalisation in children with mild to moderate wheezing associated with viral infection in those given oral steroids compared to placebo.13 However, a recent Australian study concluded that prednisone reduced the length of stay in children with mild-moderate viral associated wheeze.14
Steroids should still be used for patients with pre-school wheeze who have:
- frequent episodes
- ongoing frequent bronchodilator use (<2 hourly)
- severe or life-threatening symptoms
- a requirement for intensive care unit admission
Consider steroids for pre-school children with a history suggestive of an asthma phenotype e.g. atopy and maternal family history of asthma.
The systemic steroid of choice is oral prednisone/prednisolone.
Studies have shown that an alternative steroid, dexamethasone, with benefits of a longer half-life, may also be a suitable treatment for children with wheeze. In a recent paediatric study, dexamethasone was found to have a similar efficacy as prednisone when comparing respiratory scores, with a single dose of 0.3mg/kg dexamethasone having the same efficacy as a course of prednisone to prednisone 0.1mg/kg for 3 days.16 However, dexamethasone suspension is not readily available in the community or non-tertiary hospitals.
|Prednisolone (PO) dosing for the treatment of wheeze in pre-school children
||2mg/kg (max 50mg)
|Day 2 and 3
Can extend course to 5 days if still symptomatic after 3-day course
Target oxygen saturations (SpO2) and the use of low and high flow oxygen therapy is highly variable depending upon local practice and resource availability.
The following section should be used as a guide, with local policies followed at all times.
There is no evidence to clearly define an optimal oxygen saturation (SpO2) target for young children with respiratory illnesses and therefore threshold for supplemental oxygen administration. Consensus opinion supports a target of SpO2 ≥94%. Lower saturations may be tolerated depending upon institutional practice. A study in children with bronchiolitis aged <12 months showed that a target SpO2 >90% was as safe and clinically effective as 94%.25 This study may influence future consensus opinion in other respiratory tract illnesses in children. A current randomised controlled trial studying high flow oxygen therapy for children with acute hypoxemic respiratory failure uses a cut off of ≤92% for the commencement of oxygen supplementation.26
Low flow oxygen should not be given to children for work of breathing in isolation, and the practice of “fly-by” oxygen (ie. leaving a mask adjacent the patient’s face) is discouraged. Transient (< 5 mins) desaturations below the local limit during sleep with rapid self-correction does not mandate increasing or commencing supplemental oxygen. Nurse-initiated commencement of supplemental oxygen is suitable however, a review by a medical officer should be requested at the time for cause of deterioration and, where applicable (per institutional recommendations), should be prescribed on an oxygen order form.8
Continuous oximetry should be performed in children requiring oxygen.
|Low flow oxygen for pre-school children with wheeze
|Method of delivery
*N.B. There is no role for 2-4L/min via mask.
Children with severe/life threatening respiratory distress who are not responding to inhaled bronchodilators may benefit from intravenous medications to treat bronchospasm.
Seek senior emergency/paediatric input as per local escalation protocols for children requiring magnesium sulphate. Consider seeking paediatric critical care input
Magnesium sulphate is thought to act by decreasing the uptake of calcium by bronchial smooth muscle cells, which leads to bronchodilation. In addition, magnesium may have a role in inhibiting mast cell degranulation, which reduces inflammatory mediators.17, 18 Whilst there is no clear evidence for magnesium sulphate in the treatment of pre-school wheeze it can be considered for children who are not responding to inhaled therapies.11
Magnesium sulphate should be administered using safety software syringe drivers with a standard concentration of 0.5 mmol/ml. e.g. for a patient who weighs 10kg, the magnesium sulphate dose is 0.2mmol/kg = 2 mmol. This translates to 4ml of 0.5 mmol/ml solution, and must be administered through a safety software syringe driver over 10 to 20 minutes to minimise the risk of too rapid administration and dosing errors.
|Magnesium sulphate (IV) dosing for the treatment of wheeze in pre-school children
||0.2 mmol/kg (equivalent to 50 mg/kg) infused over 20 minutes
(max 8 mmol = equivalent to 2,000mg)
||Usually minor, including:
- epigastric or facial warmth and flushing
- pain and/or numbness at infusion site
- dry mouth
Severe reactions include allergy, hypotension, respiratory depression and circulatory collapse.
||Full cardiac monitoring with blood pressure every 5 minutes.
Cease infusion if hypotension persists.
Monitor knee reflexes if repeating doses to assess for magnesium toxicity which can result in respiratory failure. Magnesium should be ceased/no further doses given if reflexes are absent.
Contact paediatric critical care specialists (onsite or via RSQ)
for children requiring salbutamol IV.
Salbutamol IV should only be used in young children with a very severe acute wheeze.24 The dosing recommendation is an initial bolus dose 100mcg/kg (max 5g) given over 20 mins of which is equivalent to 5mcg/kg/min for 20 mins. The child should be closely observed and monitored for signs of salbutamol toxicity (extreme tachycardia, lactic acidosis, and hypertension). If there are significant concerns regarding toxicity, the infusion should be slowed down or ceased. Evaluate the clinical response to this initial dose and consider progression to a salbutamol IV infusion at a rate of 1-10mcg/kg/min. The Asthma Guideline recommends starting at a higher rate initially and reducing thereafter e.g. 5 micrograms/kg/minute for the first hour, then 1–2 micrograms/kg/minute until symptoms improve.
|Salbutamol (IV) dosing for treatment of wheeze in pre-school children
||100mcg/kg infused over 20 minutes
(max 5 grams)
||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.
||Full cardiac monitoring.
Monitor venous potassium levels.
Seek senior emergency/paediatric input as per local escalation protocols for children requiring steroids IV. Consider seeking paediatric critical care input (onsite or via RSQ
Whilst oral and parenteral corticosteroids appear to have similar efficacy, intravenous steroids may be considered in child with a severe wheeze who cannot tolerate oral medication or has a decreased conscious level.
|Steroid (IV) dosing for the treatment of wheeze in pre-school children
||4mg/kg (max 200mg), 6 hourly
|Initial loading dose: 2mg/kg (max 60mg)
Day 1: 1mg/kg 6 hourly
Day 2: 1mg/kg 12 hourly
Day 3 onwards: 1mg/kg daily
Facilities with High Flow Nasal Cannula Oxygen (HFNC) Therapy and Non-Invasive Ventilation (NIV)
Contact paediatric critical care specialists (onsite or via RSQ
) for children requiring HFNC therapy. A randomised controlled study assessing the efficacy of HFNC therapy for children with acute hypoxemic respiratory failure including patients with pre-school wheeze is currently being conducted. The findings will improve our understanding of the role of HFNC therapy for pre-school wheeze.26
HFNC therapy may help avoid intubation but can also provide pre-oxygenation whilst preparation for inevitable intubation is underway.
ALERT – HFNC therapy and ongoing bronchodilator therapy. Providing bronchodilator therapy at the same time as HFNC therapy is challenging. A transient decrease to low flow oxygen or use of a specific circuit (where available) is required. Where a circuit is not available, a bolus or infusion of salbutamol IV should be given to children who are too unwell to come off HFNC therapy.
NIV including continuous positive airways pressure (CPAP) or bi-level positive airways pressure (Bi-PAP) can also be considered to help avoid intubation or pre-oxygenate for inevitable intubation e.g. child with a normal level of consciousness who is unable to maintain SpO2 at target level (≥ 94%) despite oxygen via a Hudson mask with reservoir, or has deteriorating work of breathing with increasing fatigue, tachycardia, and tachypnoea.
Requirements for HFNC
Potential concerns (QH staff only) have been raised regarding the use of HFNC therapy. Please follow local policies and procedures.
For CHQ staff, in accordance with CHQ HFNC therapy protocols (QH staff only), the child:
- should be nursed at an appropriate (1:1 or 1:2) nurse to patient ratio
- should be in an acute area such as a resuscitation room with continuous oximetry and ECG monitoring
- must have vascular access secured
- must remain nil by mouth with consideration given to the placement of a nasogastric tube to prevent gastric insufflation
Medications not routinely recommended
Routine use of the following medications is not recommended in the acute management of wheeze in a pre-school child:
- hypertonic saline
- oral beta2 agonists (e.g. salbutamol syrup) due to systemic side effects17
- inhaled corticosteroids1
- intermittent montelukast17
Preventer medication may be considered for children with recurrent episodes of wheeze (multi-trigger wheeze). Medication should be prescribed by the child’s general practitioner or paediatrician.
|Preventative medications for children with recurrent wheeze episodes (multi-trigger wheeze)
||3-month trial may be considered
RCT of long term inhaled corticosteroid demonstrated improvement (smaller effect than school-aged-children and adults) in symptoms, exacerbation rates, lung function, and airway hyper-responsiveness.19,20
||Daily montelukast may be considered as an alternative to inhaled corticosteroids for toddlers with MTW who are at high risk for asthma.21
Parents should be counselled on side effects including headaches and mood disturbance/depression.
When to consider discharge
A pre-school child with a wheezing illness may be safely discharged home providing they meet the following criteria:
- well, active child requiring salbutamol no more frequently than 3rd hourly
- Sp02 ≥ 94%
- normal hydration and toleration of diet and fluids
- parent/caregiver can safely manage the child at home, return in event of deterioration and access further medication.
Patients who are at high risk for deterioration with more severe disease or inadequate management in the community should be considered for a period of longer short stay or inpatient observation despite looking well. This includes:
- those with previous PICU admission
- non-English-speaking background
- families living > 30 minutes from a local hospital
- other 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 Pre-school Wheeze Education Checklist (QH staff only) for all children with pre-school wheeze prior to discharge.
On discharge a child should be provided with:
- with GP or paediatrician within a week, depending upon the course of the illness
When to consider admission
Facilities without a Short Stay Unit (SSU)
Consider admission if:
- severe illness – defined as respiratory distress, failure to respond to initial burst of bronchodilator or requiring oxygen
- unable to stretch bronchodilators and discharge by 4 hours
Despite meeting the clinical discharge criteria admission may be considered for the following patients:
- high risk including those with past PICU admission or previous sudden deterioration
- social issues including those who are geographically isolated from a hospital or have family issues affecting the ability to provide care at home
Facilities with a Short Stay Unit (SSU)
Considering admission to a SSU if:
- symptoms occur within 1-2 hours of initial treatment with bronchodilator AND
- no further investigations are required
Children who require bronchodilator therapy more frequently than 1 hourly require vigilant monitoring and regular review by medical staff.30 Unless specifically discussed with SSU medical and nursing staff, the child should remain in the acute assessment area of the ED.
During admission to SSU:
- salbutamol must be prescribed on a “Variable Frequency” order (for paper based charting), or as per local electronic medical record capabilities
- vital signs and respiratory assessment should be recorded in line with bronchodilator frequency or hourly if requiring oxygen supplementation30
- salbutamol frequency can be weaned (“stretched”) by appropriately trained nursing or medical staff
When to consider admission to inpatient ward from SSU
There is little evidence to support specific requirements however, consider admission for a child with:
- severe illness i.e. respiratory distress or continued need for frequent bronchodilators (every 1 to 2 hours)8 at 24 hours post presentation
- failure to progress – after 12hrs of care patient has not improved – consider poor bronchodilator responder, suboptimal frequency of administration, or alternate diagnoses
- supplemental oxygen is required