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Acute Asthma in Children

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Overview

Asthma is a chronic respiratory condition associated with airway inflammation and hyperresponsiveness leading to bronchoconstriction and wheezing. An acute asthma exacerbation describes the onset of severe asthma symptoms which may be life-threatening.

Epidemiology

  • The incidence of asthma is higher in children
  • During childhood, the prevalence of asthma is higher in boys than in girls
  • During adolescence, the prevalence of asthma is around the same in boys and girls
  • In adulthood, the prevalence of asthma is higher in girls than in boys

Risk Factors

Presentation

  • Shortness of breath over hours-days
  • Tachypnoea
  • Increased use of reliever inhalers
  • Auscultation may show:
    • Diffuse expiratory wheezing – focal wheezing suggests a foreign body
    • Reduced air entry
    • Silent chest – life-threatening as it suggests severe bronchoconstriction and very little air entry

Assessment of Severity

British Thoracic Society (BTS)/Scottish Intercollegiate Guidelines Network (SIGN) guideline

A category is met if any of the following apply:

  • Moderate asthma:
    • Oxygen saturations (SpO2) on room air ≥92%
    • No clinical features of severe asthma
  • Acute severe asthma:
    • SpO2 <92%
    • Too breathless to talk
    • Heart rate:
      • >125 /min if >5 years 
      • >140 /min if 1-5 years
    • Respiratory rate:
      • >30 /min if >5 years
      •  >40 /min if 1-5 years
    • Use of accessory neck muscles
  • Life-threatening asthma
    • SpO2 <92% and any of:
      • Silent chest
      • Poor respiratory effort
      • Agitation
      • Confusion
      • Cyanosis

Management

All patients

  • Any child with severe or life-threatening asthma should immediately be referred to hospital.
  • Oral prednisolone should be given for 3-5 days in all children with an asthma exacerbation

Mild-moderate acute asthma

  • 1st-line: 1 puff of a short-acting beta-2 agonist (SABA) via a spacer every 30-60 seconds up to 10 puffs
  • If symptoms are not relieved, continue SABA and refer to hospital

Moderate-severe acute asthma 

  • Oxygen if SpO2 <94% or working hard to breathe
  • SABA
  • Nebulisers with SABA or a short-acting muscarinic antagonist (ipratropium)
  • Oral prednisolone or IV hydrocortisone if unable to retain oral medication (e.g. vomiting)
  • If control is not attained by this point, seek senior help and consider transferral to a paediatric intensive care unit (PICU):
    • IV magnesium sulphate may be considered
    • IV salbutamol may be considered
    • IV aminophylline may be considered
    • Intensive care admission, intubation, and ventilation

Follow Up

  • Acute asthma should always be followed up with:
    • A careful history to identify any triggers
    • Checking inhaler technique and current treatment
    • A written asthma action plan aimed to prevent relapse, optimise treatment, and prevent seeking help
  • The patient’s GP should be notified within 24 hours of discharge and the patient should be seen within 2 working days.
  • Patients with a near-fatal asthma attack should be followed up by a specialist indefinitely.

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