Zambian Paediatric & Obstetrics-Gynecology (OB/GYN) Clinical Mastery

The Wheezing Child

Lesson Objectives

By the end of this lesson, learners should be able to:

Describe the common causes of wheezing in young children.
Recognize the clinical presentation and investigations for viral wheeze, asthma, airway malacia, and protracted bacterial bronchitis.
Assess the severity of bronchiolitis and asthma exacerbations.
Implement appropriate outpatient or inpatient management for bronchiolitis.
Administer oxygen and respiratory support safely in children with bronchiolitis.
Manage acute and life-threatening asthma in children, including pharmacological treatment.
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:

Normal mental state, can talk in sentences
Some accessory muscle use
PEF ≥50%, SpO2 >92%, moderate tachycardia and RR
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:

Agitated, distressed, cannot complete sentences, marked accessory muscle use
PEF 33–50%, SpO2 >92%
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:

Confused, drowsy, exhausted, unable to talk, maximal accessory muscle use
PEF <33%, SpO2 <92%, silent chest, cyanosis
Management: High-flow O2, nebulized salbutamol + ipratropium, IV steroids, IV magnesium, consider early IV salbutamol/aminophylline, PICU referral

Discharge Plan:

Stable on 4-hourly salbutamol, complete 3-day prednisolone course
Education on triggers, inhaler technique, written action plan
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

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