Asthma

Disclaimer

These guidelines have been produced to guide clinical decision making for the medical, nursing and allied health staff of Perth Children’s Hospital. They are not strict protocols, and they do not replace the judgement of a senior clinician. Clinical common-sense should be applied at all times. These clinical guidelines should never be relied on as a substitute for proper assessment with respect to the particular circumstances of each case and the needs of each patient. Clinicians should also consider the local skill level available and their local area policies before following any guideline. 

Read the full PCH Emergency Department disclaimer.

Aim

To guide staff with the assessment and management of acute asthma.

Definition

Asthma is a chronic inflammatory disease of the lower respiratory tract that leads to acute episodes of bronchospasm leading to cough and wheezing.

Background

General

  • Around 14-16% of Australian children are currently living with asthma.
  • This guideline applies to children 12 months of age and over and addresses the Emergency Department Management of acute asthma in the first hour of presentation.
  • Potential triggers for an acute asthma exacerbation can include:
    • Allergy (there is a strong link between asthma and atopy).
    • Viral upper and lower respiratory tract infections
    • Environmental: cigarette smoke including passive smoking, air pollution, cold air
    • Drugs
    • Exercise

Recent changes in practice

  • In the treatment of asthma / wheezing, the use of pressurised metered dose inhalers (pMDIs) with spacer devices has to a large extent superseded the use of nebulisers as the preferred means of delivery of inhaled aerosol solutions.
  • Perth Children's Hospital uses the small volume spacer for all ages.

Assessment

  • Continue reassessing the patient’s condition and their response to treatment.
  • A deteriorating patient needs to be identified early and treated more aggressively.
  • It is not necessary for all clinical criteria to be met for a patient to be considered ‘severe’ or ‘critical’.
  • Wheeze is not an indicator of severity.

History

  • Asthma classification: infrequent or frequent intermittent, persistent.
  • Potential triggers.
  • Previous Paediatric Intensive Care Unit admissions.
  • Medications recently used: reliever, preventer, steroids.
  • Symptoms of a viral upper respiratory tract infection.
  • Symptoms such as wheezing, cough, chest tightness, dyspnoea.
  • Personal or family history or atopy or eczema.

Examination

  • Observations: pulse rate, respiratory rate, temperature, oxygen saturations.
  • Mental status: lethargic, drowsy.
  • Ability to talk in sentences, phrases or single words.
  • Evidence of a viral upper or lower respiratory tract infection.
  • Chest hyperinflation.
  • Work of breathing: degree and type of recession (eg: mild, moderate, severe; subcostal, intercostal, sternal, tracheal tug), and use of accessory muscles, head bobbing, nasal flaring.
  • Chest auscultation: air entry (normal, reduced, equal on both sides), wheeze, crackles. Beware the SILENT CHEST.
  • Unequal air entry is often due to mucus plugging.

Investigations

  • Peak expiratory flow rate (PEFR) measurements are not routinely performed for children who are acutely unwell or unfamiliar with having their PEFR measured (usually older than 7 years).
  • Chest X-rays are not routinely required in children with acute wheeze.
  • Indications for a chest X-ray may include:
    • deteriorating clinical state
    • poor response to treatment.
  • Blood gases are not routinely done unless patients are critical and going to a Paediatric Intensive Care Unit – in this case consider a venous blood gas.

Differential diagnoses

  • Viral induced wheeze, viral pneumonitis.
  • Inhaled foreign body.
  • Recurrent cough (post viral, non-specific). 

Management

Initial management

  • pMDIs are used to deliver medication with a spacer
  • It is reasonable to change to a nebuliser if the patient is unable to cooperate with a spacer or the patient is deteriorating clinically.

Further management

  • Reassess the patient’s condition within 20 minutes following salbutamol to assess for responsiveness. 
  • If responding observe for 1-1.5 hours post salbutamol and then review to determine need for admission to either ESSU or inpatient ward 
  • Patients who are not responding to treatment, or who are deteriorating, need to be identified early and treated more aggressively.
  • ESSU admission criteria includes: 
    • Frequency of salbutamol administration via puffer and spacer >45 minutely.
    • Receiving no more than 2L of oxygen via nasal prongs.
    • Likely to be discharged within 24 hours (Note: Seek early senior medical help with decision to admit).
  • An admission to the medical ward at PCH or a peripheral hospital under the General Paediatric Team, for more prolonged treatment for patients not meeting ESSU criteria.

Medications

Acute dosing

pMDI’s:

Salbutamol = 100 micrograms per actuation. pMDIs are used via spacer with 1 actuation at a time, with 3 normal tidal breaths between each actuation. Protocol for salbutamol in acute asthma is:

  • Children < 6 years: 6 puffs
  • Children > 6 years: 12 puffs
  • For moderate to severe asthma, pMDIs are given 20 minutely over 40 minutes (3 times). Then the patient should be reassessed to decide the timing for the next dose.
Ipratropium is no longer used for mild and moderate asthma.

Spacers

pMDIs must be used with a small volume spacer and mask for all children.

Nebulisers

Nebulisers are driven with oxygen at 8L/min Salbutamol:
  • Ventolin nebules (given neat, not diluted with saline).
  • Children < 5 years: 2.5 mg/2.5mL.
  • Children > 5 years: 5mg/ 2.5 mL.

Ipratropium

  • Children < 5 years: 125 micrograms.
  • Children > 5 years: 250 micrograms.

Steroids

  • Oral prednisolone is given 1mg/kg (max 50 mg) orally each morning for three mornings.
  • Alternatively a one off dose of dexamethasone 0.3mg/kg may be used.
  • More severe patients may require intravenous hydrocortisone 4mg/kg (maximum 100mg) 6 hourly during admission.

Other medications

Aminophylline, Magnesium Sulphate, Salbutamol Nebulised, Salbutamol Intravenous.

Discharge medication

  • Oral steroids (complete a 3 day course).
  • Bronchodilator as per Asthma Action Plan.
  • Prophylaxis – usually organised by General Practitioner or General Paediatric Team at follow up appointment.

Discharge criteria

Patients can be discharged when:
  • Demonstrated clinical improvement 1 hour following initial therapy. If necessary, reassess again after 30 minutes 
  • Discharge from ESSU should occur when condition has stabilised and parents are confident in the ongoing management. In general discharge from ESSU after midnight should not occur until daylight.
  • Parents are able to administer salbutamol at home (asthma education may be required).
  • Oxygenation saturations of < 92% does not  preclude discharge if the patient is responding and clinically well

Discharge medications

  • Complete the oral steroid course (3 days) - if commenced - if ongoing regular salbutamol required.
  • Salbutamol (or other bronchodilator) as required.
  • Prophylaxis if required (as per the National Asthma Campaign Guidelines).

Referrals and follow-up

  • ED medical and nursing staff can provide asthma / wheeze education
  • Follow up can be with:
    • General Practitioner.
    • Private Paediatrician (General or Respiratory).
    • PCH Outpatient Clinic (General Paediatrics, Respiratory).
    • Patients can be offered follow up with the Asthma Foundation (external site)
  • A range of services are offered at the Foundation including:
    • Group Education sessions.
    • Over-the-phone Education sessions.
    • Individual Education sessions at the Asthma Foundation Centre or in certain metropolitan clinics.

Health information (for carers)

Contributing factors – identify and discuss relevant environmental and allergy factors with the family:
  • Tobacco smoke
  • Viral infections
  • Exercise
  • Allergens – inhaled or ingested.
Where possible give appropriate education and advice to the patient and family regarding allergen avoidance if warranted.

Management paperwork

  • Asthma Action Plan – to be completed and explained by the Emergency Doctor for all patients with asthma prior to discharge – either the generic PCH Action Plan or a hand-written Action Plan can be used. Generic Action Plans are available in the Asthma Education Pack given to patients.
  • Discharge letter for the General Practitioner.

Bibliography

  1. AMH Children's Dosing Companion (online). Adelaide: Australian Medicines Handbook Pty Ltd; 2014 July. Available from: https://childrens.amh.net.au
  2. National Asthma Campaign Guidelines https://www.asthmahandbook.org.au/download-order/guide accessed Feb 2017
  3. Can Fam Physician. 2011 Oct; 57(10):1134-6. Single-dose dexamethasone for mild-to-moderate asthma exacerbations: effective, easy, and acceptable. Cross KP1, Paul RI, Goldman RD.
  4. Cochrane Database Syst Rev. 2016 May 13;(5):CD011801. doi: 10.1002/14651858.CD011801.pub2. Different oral corticosteroid regimens for acute asthma. Normansell R1, Kew KM, Mansour G
  5. Ann Emerg Med. 2016 May;67(5):593-601.e3. doi: 10.1016/j.annemergmed.2015.08.001. Epub 2015 Oct 14. A Randomized Trial of Single-Dose Oral Dexamethasone Versus Multidose Prednisolone for Acute Exacerbations of Asthma in Children Who Attend the Emergency Department. Cronin JJ1, McCoy S1, Kennedy U2, An Fhailí SN3, Wakai A4, Hayden J3, Crispino G5, Barrett MJ6, Walsh S1, O'Sullivan R7

Endorsed by:  Director, Emergency Department  Date:  Feb 2017


 Review date:   Jan 2021


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Last reviewed: 01-02-2017
Last updated: 07-06-2019