Overview

• Viral-Induced Wheeze

  • Acute wheezy illness caused by viral infection (typically RSV or Rhinovirus).
  • Features suggesting Viral-Induced Wheeze rather than Asthma → presenting <3 years of age, no atopic history, only occuring during viral infections.

  <aside> 💡 Wheeze → <1yo: bronchiolitis, 1-5yo: viral-induced wheeze, >5yo: asthma.

  • Unilateral Wheeze in Child <3yo → inhaled foreign body until proven otherwise (typically right-sided as right bronchus is more vertical). </aside>

Making Diagnosis

Clinical Features

Investigations

• 1st Line for Suspected Asthma → spirometry and bronchodilator reversibility.
  • FEV1 → best way to diagnose suspected asthma. Will be <80% of predicted amount for the age and sex of the patient.
  • Improvement of FEV1 >12% indicates reversibility.
• Bedside → basic obs (RR, HR, O2), listen to chest, peak flow, check inhaler technique.

Management Plan

• Acute Asthma ⇒
  • Moderate vs Severe vs Life Threatening
  • Oxygen (if life-threatening/severe or hypoxic [<92%]) → high flow oxygen through venturi mask or high flow nasal cannulae.
  • Bronchodilator Burst Therapy ⇒
    • If not on oxygen or moderate asthma attack → 10 puffs of salbutamol via a MDI and spacer. (Every 30-60 seconds of salbutamol through a spacer, 5 breaths per pump).
    • If on oxygen or 10 puffs hasn’t worked → give nebulised salbutamol (3x) + ipratropium bromide. REPEAT EVERY 20 MINS. INVOLVE SENIORS IF BURST THERAPY HAS FAILED TO WORK.
      • Other Bronchodilators (INTRAVENOUS) → 1st IV Tx: IV magnesium sulphate. After this consider IV salbutamol or IV aminophylline (monitor ECG for hypokalaemia).
      • Panic Step → intubate and ventilate. Transfer to ICU.
  • Steroids (ALL CHILDREN HAVING ASTHMA ATTACK) → oral prednisolone within 1 hr. Start early in treatment.
    • On Discharge → oral prednisolone for 3-5 days.
  • Discharge once symptom free for 4 hours (don’t need salbutamol for 4 hours) and PEFR >75%. After discharge, follow-up in 48 hours by GP.
• Asthma Management (Ages 5-16) ⇒
  • Step 1 (newly-diagnosed asthma) → SABA (salbutamol).
  • Step 2 (not controlled with SABA OR symptoms ≥3 times/wk or night-time waking) → SABA + Low-Dose ICS (beclamethasone or budesonide).
    • SABA (Blue) → reliever. ICS (Brown) → preventer (twice a day, at morning and night). Always check parents know correct inhaler technique.
  • Step 3 → SABA + ICS + LTRA (montelukast).
  • Step 4 → SABA + ICS + LABA (salmeterol).
• Asthma Management (Age <5) ⇒
  • Step 1 (newly-diagnosed asthma) → SABA.
  • Step 2 (not controlled with SABA alone OR symptoms ≥3 times/wk or night-time waking [STRAIGHT TO THIS]) → SABA + 8-Week Trial of Moderate-Dose ICS.
  • Step 3 → SABA + ICS + LTRA.
  • Step 4 → stop LTRA and refer to paediatric asthma specialist.
• Viral-Induced Wheeze ⇒
  • 1st Line → SABA (Salbutamol) utilising ‘Burst Therapy’. Given 10 puffs. Typically given hourly to manage the acute episode.
    • 2nd Line → Oral Montelukast or Inhaled Corticosteroid.
  • Follow-up required within 48 hours of presentation if not admitted to hospital, or 2 working days of discharge.

Complications →

Prognosis →