management of acute severe asthma in children 1 year and over

Last edited 11/2019

MANAGEMENT OF ACUTE ASTHMA IN CHILDREN AGED 1 YEAR AND OVER (management of acute asthma in children under 1 year should be under the direction of a respiratory paediatrician)

Asthma severity should be assessed and if a patient has signs and symptoms across categories, always treat according to their most severe features (1).

Acute severe:

• SpO2 <92%
• PEF 33-50% best or predicted
• Can't complete sentences in one breath or too breathless to talk or feed
• Heart rate
  • >125 (>5 years) or
  • >140 (1-5 years)
• Respiratory rate
  • >30 breaths/min (>5 years, or >40 (1-5 years)

Life threatening

• SpO2 <92%
• PEF <33% best or predicted
• Silent chest
• Cyanosis
• Poor respiratory effort
• Hypotension
• Exhaustion
• Confusion

Criteria for Admission:

• increase beta2 agonist dose by giving one puff every 30-60 seconds, according to response, up to a maximum of ten puffs
  
  
• parents/carers of children with an acute asthma attack at home and symptoms not controlled by up to 10 puffs of salbutamol via a pMDI and spacer, should seek urgent medical attention
  
  
• if symptoms are severe additional doses of bronchodilator should be given as needed whilst awaiting medical attention
  
  
• paramedics attending to children with an acute asthma attack should administer nebulised salbutamol, using a nebuliser driven by oxygen if symptoms are severe, whilst transferring the child to the emergency department
  
  
• children with severe or life-threatening asthma should be transferred to hospital urgently
  
  
• consider intensive inpatient treatment of children with SpO2 <92% in air after initial bronchodilator treatment

The following clinical signs should be recorded:

• pulse rate - increasing tachycardia generally denotes worsening asthma; a fall in heart rate in lifethreatening asthma is a pre-terminal event
  
  
• respiratory rate and degree of breathlessness - ie too breathless to complete sentences in one breath or to feed
  
  
• use of accessory muscles of respiration - best noted by palpation of neck muscles
  
  
• amount of wheezing - which might become biphasic or less apparent with increasing airways obstruction
  
  
• degree of agitation and conscious level - always give calm reassurance

NB Clinical signs correlate poorly with the severity of airways obstruction. Some children with acute severe asthma do not appear distressed.

Initial management - acute asthma

• Oxygen
  • children with life-threatening asthma or SpO2 <94% should receive high-flow oxygen via a tight fitting face mask or nasal cannula at sufficient flow rates to achieve normal saturations of 94-98%.

Bronchodilators:

• inhaled beta2 agonists are the first-line treatment for acute asthma in children
  
  
• a pMDI + spacer is the preferred option in children with mild to moderate asthma
  
  
• individualise drug dosing according to severity and adjust according to the patient’s response
  
  
• if symptoms are refractory to initial beta2 agonist treatment, add ipratropium bromide (250 micrograms/ dose mixed with the nebulised beta 2 agonist solution)
  
  
• repeated doses of ipratropiumbromide should be given early to treat children who are poorly responsive to beta2 agonists
  
  
• consider adding 150 mg magnesium sulphate to each nebulised salbutamol and ipratropium in the first hour in children with a short duration of acute severe asthma symptoms presenting with an SpO2 <92%
  
  
• discontinue long-acting beta 2 agonists when short-acting beta2 agonists are required more often than four hourly

Steroid Therapy:

Give oral steroids early in the treatment of acute asthma attacks in children

• use a dose of 10 mg prednisolone for children under 2 years of age, 20 mg for children aged 2-5 years and 30-40 mg for children >5 years
  • those already receiving maintenance steroid tablets should receive 2 mg/kg prednisolone up to a maximum dose of 60 mg
    
    
• repeat the dose of prednisolone in children who vomit and consider intravenous steroids in those who are unable to retain orally ingested medication
  
  
• treatment for up to three days is usually sufficient, but the length of course should be tailored to the number of days necessary to bring about recovery. Tapering is unnecessary unless the course of steroids exceeds 14 days

Second line treatment for acute asthma:

• consider early addition of a single bolus dose of intravenous salbutamol (15 micrograms/kg over 10 minutes) in a severe asthma attack where the patient has not responded to initial inhaled therapy
  
  
• aminophylline is not recommended in children with mild to moderate acute asthma
  
  
• consider aminophylline for children with severe or life-threatening asthma unresponsive to maximal doses of bronchodilators and steroids
  
  
• in children who respond poorly to first-line treatments, consider the addition of intravenous magnesium sulphate as first-line intravenous treatment (40 mg/kg/day)

DISCHARGE PLANNING AND FOLLOW UP

• Children can be discharged when stable on 3-4 hourly inhaled bronchodilators that can by continued at home. PEF and/or FEV1 should be >75% of best or predicted and SpO2 >94%.
  • Arrange follow up by primary care services within two working days
  • Arrange follow up in a paediatric asthma clinic within one to two months
  • Arrange referral to a paediatric respiratory specialist if there have been life-threatening features

Management of acute asthma in children under 1 year should be under the direction of a respiratory paediatrician

Reference:

• (1) British Thoracic Society (BTS)/Scottish Intercollegiate Guidelines Network (SIGN) 2019. British Guideline on the Management of Asthma. A national clinical guideline.