Pre-school wheeze – Emergency management in children

Purpose

This document provides clinical guidance for all staff involved in the care and management of children aged one to five years presenting to an Emergency Department (ED) in Queensland with a wheezing illness.

This guideline has been developed by senior ED clinicians and Paediatricians across Queensland, with specialist input from Paediatric Respiratory staff, 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.

Guidance for wheezing children aged less than one year can be found in the Bronchiolitis – Emergency management in children Guideline. For wheezing children over five years refer to the Asthma – Emergency management in children Guideline.

Introduction

Wheeze is a continuous high-pitched sound with musical quality emitting from the chest during expiration¹ often associated with increased work of breathing². Pre-school wheeze is also referred to as reactive airways disease. Wheeze is a very common ED presentation in children that is usually caused by intercurrent viral infection or other environmental triggers. Evidence suggests that up to 30% of children will have at least one episode of wheezing prior to their third birthday,³ over half will have more than one episode⁴ and 60% will stop wheezing by six years of age.

Pre-school wheeze vs asthma

The term asthma is not commonly used to describe a wheezing illness in pre-schoolers, as this cohort is heterogeneous and includes a spectrum of children from those with an episode of viral-induced wheeze to those with asthma¹. Pre-schoolers commonly experience wheeze during discrete time periods, often in association with clinical evidence of viral infection, with symptoms absent between episodes. Repeated episodes tend to occur seasonally and it usually declines over time, improving by six years of age.

Viral infection is a common trigger but other triggers include tobacco smoke, allergen exposure, mist, crying, laughter and exercise.

Risk factors for a future diagnosis of asthma include:

• early onset of wheeze
• personal history of atopy e.g. eczema
• maternal asthma

Several clinical prediction models for future risk of asthma have been developed based on family history, presence of atopy, indirect evidence of airway inflammation (such as peripheral blood eosinophil count) and severity of pre-school wheeze. Further work in this area is needed before any conclusions can be drawn⁵.

Assessment

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

History should include specific information on:

• the wheeze, other noises and features of respiratory distress
• pre-hospital salbutamol use (dose and frequency)
• family history (including mother and sibling/s) of asthma and atopy
• smoking status of household members
• risk of foreign body inhalation
• severity and frequency of previous episodes (eg. PICU admission)
• comorbidities (eg neuromuscular disorders)

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 child should be assessed within the time frame recommended by the triage category. General appearance, mental state and level of respiratory distress are the most important markers of illness severity.⁷ Signs of respiratory distress in pre-school children include accessory muscle use, abdominal breathing, intercostal recession, subcoastal recession and tracheal tug.

Adapted from National Asthma Council Australia and Department of Health and Ageing, Australian Government⁶.

Differential diagnosis

Wheeze is due to narrowing of intrathoracic airways and expiratory flow, irrespective of the underlying cause. Consider further investigation if assessment (history and examination) identifies any unusual features which suggest a non-viral cause.

Investigations

Investigations are not routinely recommended for a pre-school wheeze diagnosis². They may be considered in a child with a severe or life-threatening exacerbation who is not responding to treatment, or an alternative diagnosis is being considered.

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

Viral PCR testing is not routinely recommended unless the result will alter management, for example some vulnerable children may require Influenza or Covid specific treatment.

Management

Acute management

Refer to the flowchart [PDF 656.48 KB] for a summary of the recommended emergency management and medications for a pre-school child with a wheezing illness:

Management is comprised of medications targeted at relieving acute bronchospasm, alleviating lower airway inflammation, and providing respiratory support in the form of oxygen and non-invasive ventilation. Corticosteroids may not be indicated in children with pre-school wheeze, especially those who present for the first time or with mild to moderate wheeze.

Bronchodilators

Salbutamol (short acting inhaled beta2 agonist) is recommended for all pre-schoolers with wheeze⁷. Clinical review of the child post salbutamol is essential to determine treatment response. Wheeze alone, without increased work of beathing, is not necessarily an indication for salbutamol. The patient should be medically assessed no later than one hour after salbutamol administration to ensure the patient has responded to salbutamol. Providing hourly observation allows for review of the respiratory parameters (see table above) and if a further dose of salbutamol is needed. Parental concern or desaturation may prompt a review prior to this and salbutamol may be required prior to the 1 hour reassessment. Thus a patient may stretch with hourly increments after their initial dosing or they may be able to go straight to 3 hourly salbutamol.

Monitor oxygen saturations continuously if administering Salbutamol more often than every two hours. Bronchodilators may produce a paradoxical effect in children with underlying structural abnormalities such as bronchomalacia or tracheomalacia⁷.

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

MDI and spacer vs nebuliser

• MDI (with spacer +/- mask) is preferred as:
  • faster (nebuliser requires a child to sit still for at least 10 minutes).
  • less facial and oropharyngeal deposition of medication
• Nebuliser is recommended for children with
  • oxygen requirement
  • severe or life-threatening exacerbation
  • children who are not able to co-ordinate taking a deep breath through the spacer should be given nebulised medication⁸

How to use a spacer

• Most new spacers require priming to negate electrostatic charge (and optimise drug delivery). Prime spacer with 10 Salbutamol puffs.
• Shake MDI before each puff. Administer one puff at a time into the spacer (+/- face mask).
• The child clears the medication from the spacer by taking four breaths following each puff.

Ipratropium bromide

A Cochrane review of the effect of adding an anticholinergic bronchodilator (Ipratroprium bromide) to salbutamol, shows reduced rate of hospital admission and improved side effect profile⁹. While there is no conclusive evidence for anticholinergics in children with mild exacerbations, it should be considered for children with moderate to severe symptoms in conjunction with Salbutamol MDI or combined with Salbutamol in nebuliser reservoir⁸.

Steroids

Steroids are recommended for pre-school children with wheeze with:

• frequent episodes
• ongoing bronchodilator use more frequently than every two hours
• severe or life-threatening symptoms¹⁰

Consider steroids for pre-school children with a history suggestive of an asthma phenotype e.g. atopy¹⁰.

While the evidence is still evolving, steroids are not currently recommended for initial therapy of pre-school children who present for the first time or infrequently with mild to moderate wheeze. A recent UK metanalysis concluded that Prednisone had a clear benefit at reduced length of hospital stay in children with viral associated wheeze¹¹.

The traditional oral corticosteroid of choice is oral Prednisone/Prednisolone. However, dexamethasone has been shown to be non-inferior to prednisone and has the advantage of being a single dose, eliminating the need for steroids on discharge^12,13.

Intravenous medications

Steroids

Seek senior emergency/paediatric input as per local practice for children requiring steroids IV. Consider seeking paediatric critical care input (onsite or via RSQ).

Consider in a child with severe or life-threatening wheeze who cannot tolerate oral medication or is not responding to inhaled bronchodilators and oral corticosteroids.

Magnesium sulphate

Seek senior emergency/paediatric input as per local practice for child requiring magnesium sulphate. Consider contacting paediatric critical care.

Consider in child with severe/life-threatening respiratory distress who is not responding to inhaled bronchodilators and corticosteroids.

Magnesium sulphate is thought to act by decreasing the uptake of calcium by bronchial smooth muscle cells, which leads to bronchodilation. In addition, it may have a role in inhibiting mast cell degranulation, which reduces inflammatory mediators¹⁴. There is no clear evidence to support use for the treatment of pre-school wheeze¹⁵.

Administer Magnesium sulphate using safety software syringe drivers with a standard concentration of 0.5 mmol/ml. Each Magnesium sulphate 50% vial has a strength of 2 mmol/ml. Once the dose is drawn up, the dose should be diluted to a standard concentration of 0.5 mmol/ml e.g. a 10 kg child, the Magnesium sulphate dose is 0.2mmol/kg = 2 mmol. Draw up 1mL from the 2 mmol/ml vial and then dilute the dose to 4ml with a compatible fluid to give a standard concentration of 0.5 mmol/ml. Administer through a safety software syringe driver over 20 minutes.

Intravenous Salbutamol

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

Salbutamol IV is only recommended for children with a very severe acute wheeze.¹⁶

Administer an initial bolus dose and monitor closely for signs of Salbutamol toxicity. Slow or cease infusion if significant concerns. Evaluate the clinical response to this initial dose and consider progression to a Salbutamol IV infusion.

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 wheeze 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 admission¹⁷. It is also associated with numerous side effects including vomiting⁴. Aminophylline should not be given as an intravenous infusion in the patient already taking oral Theophylline. Please see CREDD for dosing.

Intramuscular Adrenaline

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

Consideration should be given for the role of intramuscular adrenaline, especially if there is a known history of anaphylaxis or new allergen exposure. Severe bronchoconstriction will limit Salbutamol efficacy via the inhalation route.

Oxygen therapy

Oxygen should be initiated for children who are hypoxic (saturations < 90%) once initial therapy has been delivered¹⁸. It is not uncommon for children to desaturate related to an initial V/Q mismatch during initiation of therapy or while asleep due to reduced respiratory effort. It is important to promptly review children who are desaturating to formulate an opinion of cause and therefore management. If considered due to respiratory failure, adjunct respiratory therapy should be considered such as HFNC.

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

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

While early use of HFNC has not been shown to reduce length of hospital stay compared to standard oxygen therapy in infants with bronchiolitis¹⁹, HFNC therapy and NIV can be considered in patients with acute respiratory insufficiency who have not responded to standard therapies.

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

• is unable to maintain SpO2 greater than 90% despite oxygen via a mask
• has deteriorating work of breathing (increasing fatigue, tachycardia, and tachypnoea)
• needs pre-oxygenation while preparation for intubation is underway in a child with deteriorating level of consciousness

Nebulised salbutamol can be delivered through specific HFNC circuits (900PT562) although delivery through the circuit may be inferior. Follow local policies and procedures for delivery and ongoing management of HFNC²⁰. View View CHQ Nasal High Flow Therapy Guideline and Management of Severe Acute and Life-threatening Asthma in PICU.

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

Medications not routinely recommended

The following medications are not routinely recommended in the acute management of pre-school wheeze⁸:

• hypertonic saline
• oral beta2 agonists (e.g. Salbutamol syrup) due to systemic side effects
• intermittent montelukast

Ongoing management

Patients presenting to Emergency with recurrent flares of pre-school wheeze may benefit from a 3 month trial of a preventer if they have had several acute episodes in the previous 12 months. Consider introducing a preventer inhaler, such as Fluticasone, if any of the following criteria are met²¹.

• More than one exacerbation requiring admission, including Short Term Treatment Area (STTA) every 6 weeks or more than 6 exacerbations per year
• Symptoms which occur once per week and disrupt child’s sleeping or play
• Pre-school wheeze exacerbation requiring medical or ICU admission
• Chronic cough thought to be related to pre-school wheeze

Follow up should occur with the GP to determine efficacy of the trial at the end of 3 months.

On discharge a child should be provided with:

• Discharge letter
• Wheeze Action Plan – copies for family, general practitioner, and medical record
• Pre-school wheeze - Children's Health Queensland
• Puffers and Spacers factsheet
• Asthma educational video
• 1800 ASTHMA | Book a Call

Follow-up

• Reflect initiation of inhaled corticosteroids on Wheeze Action Plan (WAP)
• With GP or Paediatrician to review outcome of trial of preventer inhaler at 4-6 weeks.

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 children who meet ALL of the following:

• well, active child requiring Salbutamol no more frequently than every three hours
• Sp02 greater than or equal to 90%
• normal hydration and toleration of diet and fluids
• parent/caregiver can safely manage the child at home, return in the event of deterioration and access further medication.

Consider a longer period observation in STTA or inpatient service for the despite looking well for a child with a history of sudden deterioration or admission to critical care despite looking well.

An assessment of the family’s ability to safely manage the child at home should be done as per the Pre-school Wheeze Disease Education Checklist [DOCM] (QH staff only) prior to discharge.

On discharge a child should be provided with:

• Discharge letter
• Wheeze Action Plan – copies for family, general practitioner, and medical record
• Pre-school Wheeze factsheet and Puffers and Spacers factsheet

Follow-up

• with GP or Paediatrician within a week, or earlier depending upon the course of illness

When to consider admission

Facilities without a Short Term Treatment Area (STTA)

Consider admission for child with:

• severe illness i.e. ongoing respiratory distress and failure to respond to initial burst of bronchodilator or requiring oxygen
• unable to stretch bronchodilators within four hours of ED presentation

Despite meeting the clinical discharge criteria admission may be considered for the following patients:

• 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 Term Treatment Area (STTA)

Considering admission to a STTA if:

• symptoms occur within one to two hours of initial treatment with bronchodilator 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. Unless specifically discussed with STTA medical and nursing staff, the child should remain in the acute assessment area of the ED.

During admission to STTA:

• record vital signs and respiratory assessment 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 STTA

There is little evidence to support specific requirements and local practices will dictate criteria for admission from STTA to an inpatient ward. Consider admission for the following:

• severe illness i.e. respiratory distress or continued need for frequent bronchodilators (every one to two hours) at 24 hours post-presentation
• clinical deterioration with a need to escalate treatment
• failure to improve after 12 hours of care (at which point consider poor bronchodilator responder, suboptimal frequency of administration, or alternate diagnoses)
• ongoing or increasing requirement for supplemental oxygen

Related documents

Guideline

• Asthma - Emergency management in children
• Management of Severe Acute and Life-threatening Asthma in PICU

Forms and factsheets

• Pre-school Wheeze Disease Education Checklist [DOCM] (QH staff only)
• Wheeze Action Plan
• Pre-school Wheeze factsheet
• Puffers and Spacers factsheet

Educational videos

• Asthma video series