The Wheezing Child
Lesson Objectives
By the end of this lesson, learners should be able to:
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Describe the common causes of wheezing in young children.
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Recognize the clinical presentation and investigations for viral wheeze, asthma, airway malacia, and protracted bacterial bronchitis.
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Assess the severity of bronchiolitis and asthma exacerbations.
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Implement appropriate outpatient or inpatient management for bronchiolitis.
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Administer oxygen and respiratory support safely in children with bronchiolitis.
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Manage acute and life-threatening asthma in children, including pharmacological treatment.
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Understand long-term management and follow-up for persistent asthma.
Description
Wheezing is a common presentation in young children. Determining the cause may be challenging and often requires a trial of treatment. Parents’ descriptions of wheeze may be inaccurate; video recordings or impersonation can assist. Asthma is common, but other causes, such as viral wheeze, airway malacia, and protracted bacterial bronchitis (PBB), should be considered, especially if asthma treatment is ineffective.
Causes of Wheezing
| Condition | Estimated Incidence | Clinical Signs | Investigations | Expected Clinical Course | Management |
|---|---|---|---|---|---|
| Viral Wheeze / Bronchiolitis | Very common, especially <2 years; 50% have ≥1 wheezing episode | Wheeze with respiratory infection; may be singular or recurrent; crackles/rhonchi on auscultation | Usually none; nasal samples for virology optional | 60% outgrow by 6 years; 1 in 5 outgrow after 7–8 years | Trial salbutamol if >1 yr; supportive care: monitor, adequate fluids (>50% intake), observe for distress |
| Asthma | 15–20% of paediatric population | Wheeze on a regular basis; persistent/interval symptoms between viral episodes, night cough, exercise-triggered | Spirometry with bronchodilator response ≥5 yrs (if available) | Lifelong; variable course | Regular salbutamol, consider oral prednisolone 5 days; preventer therapy indicated |
| Airway Malacia (tracheomalacia/bronchomalacia) | 1 in 2100 | Stridor, cough, rattling; children usually well (‘happy wheezers’) | Bronchoscopy (diagnostic but not always necessary) | Resolves by age 2; secondary PBB may occur | Usually no treatment; refer if worsening or failure to thrive |
| Protracted Bacterial Bronchitis (PBB) | Unknown | Chronic wet cough >4 weeks; concurrent wheeze/rattly breathing common | Bronchoscopy may assist; usually unnecessary; X-ray often normal | Resolves with 1–2 antibiotic courses | 2–6 week course of antibiotics, commonly amoxicillin/clavulanic acid 20 mg/kg twice daily |
Bronchiolitis
Description:
Inflammation of the bronchioles usually due to acute viral infection. Begins with URTI followed by progressive respiratory distress and fever. Resolves in 7–10 days; peak severity 2–3 days post-onset.
High-risk infants: Chronic lung disease, congenital heart disease, neurological conditions, trisomy 21, postnatal smoke exposure, premature (<32 weeks), neuromuscular disorders, immunodeficiency.
Assessment of Severity
| Severity | Mental Status | Respiratory Rate | Accessory Muscle Use | SpO2 (Room Air) | Apnoeic Episodes | Feeding |
|---|---|---|---|---|---|---|
| Mild | Normal | Normal – mild tachypnoea | Nil to mild chest wall retraction | >92% | None | Normal |
| Moderate | Some/intermittent irritability | Increased | Moderate chest wall retractions, tracheal tug, nasal flaring | 90–92% | May have brief apnoea | May have difficulty/reduced |
| Severe | Increasing irritability/lethargy/fatigue | Marked increase or decrease | Marked chest wall retractions, tracheal tug, nasal flaring | <90%, may not correct with O2 | Frequent/prolonged (>20s) | Reluctant/unable to feed |
Management of Bronchiolitis
| Severity | Hydration/Nutrition | Oxygen | Respiratory Support | Disposition | Parental Education |
|---|---|---|---|---|---|
| Mild | Small frequent feeds | None | Nasal prong oxygen if required | Consider outpatient if safe | Expected course, when to return |
| Moderate | NG hydration if <50% intake over 12h | Administer O2 to maintain ≥90% | Nasal prong, HFNC if nasal prongs fail | Admit; seek senior paediatric advice | Expected course, worsening symptoms, feeding advice |
| Severe | NG/IV hydration if <50% intake | Administer O2 to maintain ≥90% | HFNC, CPAP if needed | ICU review/admission if persistent desaturation or apnoea | Expected course, worsening symptoms, feeding advice |
Oxygen Therapy Guide
| Device | Flow Rate | FiO2 |
|---|---|---|
| Nasal Prong | Neonate: 1–2 L/min; Infant: 1–4 L/min | 35–40% |
| Mask (Non-Rebreather) | 10–15 L/min | 80–95% |
| High Flow Nasal Cannula (HFNC) | Preterm: 1 L/min; Term neonate: 2 L/min; Infant: 4 L/min; Child: 4–8 L/min | 50% |
Treatment NOT recommended: beta-2 agonists, corticosteroids, adrenaline (unless peri-arrest), antibiotics, antivirals.
Acute Exacerbation of Asthma
Moderate Asthma:
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Normal mental state, can talk in sentences
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Some accessory muscle use
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PEF ≥50%, SpO2 >92%, moderate tachycardia and RR
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Management: Continuous O2 monitoring, high-flow O2 via NRB mask, β2-agonist via inhaler + spacer, ± Ipratropium, oral prednisolone (20–40 mg/day depending on age)
Acute Severe Asthma:
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Agitated, distressed, cannot complete sentences, marked accessory muscle use
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PEF 33–50%, SpO2 >92%
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Management: Continuous O2 monitoring, high-flow O2, nebulized salbutamol + ipratropium, oral steroids, consider IV magnesium/aminophylline if poor response, ABG if needed
Life-Threatening Asthma:
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Confused, drowsy, exhausted, unable to talk, maximal accessory muscle use
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PEF <33%, SpO2 <92%, silent chest, cyanosis
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Management: High-flow O2, nebulized salbutamol + ipratropium, IV steroids, IV magnesium, consider early IV salbutamol/aminophylline, PICU referral
Discharge Plan:
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Stable on 4-hourly salbutamol, complete 3-day prednisolone course
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Education on triggers, inhaler technique, written action plan
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Regular review for moderate, severe, or life-threatening cases
Long-term Asthma Follow-up
| Classification | Daytime Symptoms | Nighttime Symptoms | Prior Hospital Admission | PEFR | Pharmacological Treatment |
|---|---|---|---|---|---|
| Mild | 2–4/week | 2–4/week | None | >80% | SABA as needed; low-dose ICS 50–100 mcg 12-hourly |
| Moderate | >4/week | >4/month | One | 60–80% | SABA + medium-dose ICS; consider LABA if poor response under specialist care |
| Severe | Continuous | Frequent | >1 | <60% | SABA + low-dose ICS + LABA |