2.3 Acute Asthma

Question 1

Presentation of acute asthma?

Answer 1

• Signs of respiratory distress
• SOB and tachypnoea
• Expiratory wheeze on auscultation heard throughout the chest
• The chest can sound “tight” on auscultation, with reduced air entry
• SILENT chest is life threatening

Triggers eg infection, exercise or cold weather.

Question 2

Features of moderate, severe and life threatening asthma?

Answer 2

MODERATE:
peak flow >50% predicted
normal speech

SEVERE:
peak flow <50% predicted
sats <92%
unable to complete full sentences
signs of resp distress 
resp rate >40 in 1-5yo or >30 in >5yo
heart rate >140 in 1-5yo or >124 in >5yo

LIFE-THREATENING:
peak flow <33% predicted 
sats <92%
exhausted, poor resp effort
hypotension
silent chest
cyanosis
altered consciousness

Question 3

Management of acute asthma?

Answer 3

• OXYGEN if sats <94% or working hard
• BRONCHDILATORS (salbutamol B2 agonist, ipratropium anti-musc, IV magnesium sulphate, IV aminophylline)
• STEROIDS, pred PO or hydrocortisone IV
• ABX only if a bacterial cause is suspected (amoxicillin or erythromycin)

(mild cases can manage as outpatient with regular inhaler via a spacer, 4-6puffs every 4 hours)

Monitor serum potassium when on high doses of salbutamol as it is absorbed into cells, also causes tachycardia.

Question 4

When can you discharge an acute asthma?

Answer 4

Discharge when child is well on 6puffs 4 hourly.

Salmbutamol reducing regime in hosp: 10 puffs 2 hourly, then 10 puffs 4 hourly, then 6 puffs 4 hourly then 4 puffs 6 hourly.

Then at home: 6 puffs 4 hourly for 48 hours then 4 puffs 6 hourly for 48 hours then 2-4 puffs as required.

• Finish the course of steroids if these were started (typically 3 days total)
• Provide safety-net information about when to return to hospital or seek help
• Provide an individualised written asthma action plan