Lower respiratory disorders affect the bronchi, bronchioles, and alveoli. In young children small airways, a compliant chest wall, and limited respiratory muscle reserve mean that inflammation and mucus quickly cause hypoxemia and fatigue.

Bronchiolitis — an acute viral infection of the bronchioles in children under 2 years, most often caused by respiratory syncytial virus (RSV). Epithelial cells slough, mucus and debris plug small airways, and air trapping and atelectasis follow. Illness peaks around days 3–5 and usually resolves in 2–3 weeks. Highest risk: infants under 12 weeks, preterm infants, and those with chronic lung disease, hemodynamically significant heart disease, or immunodeficiency. It is a clinical diagnosis and treatment is supportive.

Pneumonia — infection of the lung parenchyma. Viruses (RSV, influenza, human metapneumovirus) cause most cases in children under 5; Streptococcus pneumoniae is the leading bacterial cause; Mycoplasma pneumoniae is common in school-age children and adolescents ("walking pneumonia"). Alveoli fill with exudate, causing V/Q mismatch and hypoxemia. Bacterial pneumonia can follow influenza.

Asthma — chronic airway inflammation with variable, largely reversible airflow limitation from bronchospasm, mucosal edema, and mucus plugging. It is the most common chronic disease of childhood. Triggers: viral infections, allergens (dust mites, pets, cockroaches, mold, pollen), smoke, exercise, cold air, and strong emotions. Risk factors: atopy (eczema, allergic rhinitis), family history, and tobacco smoke exposure.

Cystic fibrosis (CF) — an autosomal recessive CFTR defect that produces thick secretions in the lungs, pancreas, and other organs. Mucus plugging leads to chronic infection (Staphylococcus aureus, later Pseudomonas aeruginosa) and bronchiectasis. Full detail: Medical-Surgical topic "Cystic Fibrosis"; this topic covers pediatric nursing priorities.

General signs of lower respiratory distress

• Tachypnea — the most sensitive sign of pneumonia in young children. WHO fast-breathing thresholds: 60/min or more under 2 months, 50 or more at 2–11 months, 40 or more at 1–5 years
• Retractions (subcostal, intercostal), nasal flaring, grunting (an attempt to keep alveoli open), head bobbing
• Poor feeding, fewer wet diapers, irritability, lethargy
• Cyanosis and apnea (young infants with RSV) are late or ominous signs

Condition-specific findings

Asthma severity cues for children: agitation, confusion or drowsiness, SpO₂ below 92%, inability to complete sentences, and a rising heart rate all point to a severe attack.

Bronchiolitis (supportive care — AAP guideline)

• Nasal suction, hydration (oral, nasogastric, or IV if unable to feed), and oxygen
• Oxygen is not needed if SpO₂ stays above 90%; high-flow nasal cannula or CPAP for increasing work of breathing
• Not recommended: albuterol, epinephrine, systemic corticosteroids, antibiotics (without a bacterial infection), and chest physiotherapy; nebulized hypertonic saline is not recommended in the emergency department

RSV prevention (current)

• Long-acting monoclonal antibodies — nirsevimab or clesrovimab — one dose for infants under 8 months entering their first RSV season if the mother did not receive RSV vaccine in pregnancy or the infant was born less than 14 days after maternal vaccination
• Nirsevimab for selected high-risk children aged 8–19 months in their second season
• Maternal RSV vaccine in late pregnancy protects most infants born 14 or more days later
• These largely replace monthly palivizumab

Pneumonia

• Outpatient, previously healthy child with suspected bacterial pneumonia: high-dose amoxicillin (about 90 mg/kg/day divided in two doses, maximum 4 g/day)
• School-age child with suspected Mycoplasma: a macrolide (azithromycin)
• Hospitalized: IV ampicillin or ceftriaxone; oxygen, fluids, antipyretics
• Improvement is judged clinically within 48–72 hours: falling fever, slower breathing, less work of breathing, better feeding and activity

Asthma — GINA (ICS for everyone with asthma)

Inhaler devices by age: pMDI with spacer and face mask for ages 0–3; spacer with mouthpiece from about age 4; dry-powder inhalers only for older children who can inhale fast and deeply. Nebulizers are an alternative when a child cannot use a spacer.

Acute asthma attack

1. Inhaled SABA (albuterol) by pMDI with spacer, repeated during the first hour; ipratropium added in severe attacks
2. Oxygen if SpO₂ is below 92%; target no higher than about 95% in children 6–11
3. Systemic corticosteroid early — oral prednisolone about 1–2 mg/kg/day (maximum 40 mg) for 3–5 days
4. IV magnesium sulfate for severe attacks not responding; ICU for exhaustion, rising PaCO₂, or drowsiness
5. If the attack is part of anaphylaxis, IM epinephrine first

Cystic fibrosis — airway clearance at least twice daily, dornase alfa, hypertonic saline, CFTR modulators (elexacaftor/tezacaftor/ivacaftor for eligible children), pancreatic enzymes, fat-soluble vitamins, high-calorie high-fat diet, extra salt.

Drug safety (all doses weight-based and checked against a pediatric reference)

Listed in priority order.

1. Airway and breathing
   • Assess work of breathing, respiratory rate for a full minute, retractions, breath sounds, color, SpO₂, and level of consciousness
   • Measure SpO₂ and give humidified oxygen as needed first — before X-ray, IV insertion, or other tests
   • Suction the nose (bulb or gentle suction) before feeds and sleep in infants with bronchiolitis — clearing nasal passages improves breathing and feeding
   • Position with the head of bed elevated or upright; infants in a slightly head-up position
   • Asthma: give the bronchodilator promptly and reassess breathing, heart rate, and SpO₂ after each treatment; report a silent chest, drowsiness, or falling SpO₂ at once
2. Infection control
   • RSV: contact precautions (gown and gloves; add droplet precautions per facility policy or when influenza or another droplet pathogen is possible); single room or cohort with other RSV-positive children; strict hand hygiene; clean shared toys and equipment
   • Influenza: droplet precautions
3. Hydration and nutrition
   • Small, frequent feeds; hold oral feeds if RR is very high (commonly above about 60–70/min) and use NG or IV fluids as ordered; track intake, output, weight, and wet diapers
4. Secretion clearance
   • Adequate fluids; cough and deep breathing; incentive spirometry for older children
   • Postural drainage (CF and selected children): place the affected lobe uppermost so gravity drains it toward the main bronchi. For the lateral segment of the right lower lobe: head down, lying on the left side. Avoid head-down positions right after feeds and in children with reflux or raised intracranial pressure. Chest physiotherapy is not used for bronchiolitis or routine pneumonia
   • CF: airway clearance at least twice daily (active cycle of breathing, oscillating positive expiratory pressure devices, high-frequency chest wall oscillation vest, or percussion and drainage); bronchodilator before hypertonic saline; pancreatic enzymes with every meal and snack
5. Fever and comfort
   • Antipyretics (acetaminophen, ibuprofen if over 6 months) for comfort; light clothing and fluids. Tepid sponging is not recommended — it causes shivering and discomfort. Never use cold water or alcohol rubs
6. Evaluate treatment response — for pneumonia, the key measure is clinical improvement: vital signs, work of breathing, feeding, and activity

• Inhaler with spacer: shake the inhaler, attach to the spacer, seal the mask or lips, press once, then 6 slow breaths (mask) or one slow deep breath held about 10 seconds (mouthpiece); one puff at a time; for a quick-relief bronchodilator wait about 15–30 seconds between puffs (NAEPP), or about 1 minute with a shake if the product leaflet says so; follow the leaflet or prescriber
• Give the bronchodilator (reliever) before the inhaled corticosteroid when both are due
• After the ICS: rinse the mouth with water and spit it out (young children: give a drink or wipe the gums)
• Use a written asthma action plan (green-yellow-red zones by symptoms or peak flow); share it with school; carry the reliever at all times
• Control triggers: no smoking in the home or car, dust-mite covers, wash bedding in hot water, remove carpets and pets from bedrooms if allergic
• Asthma should not limit activity; use the reliever before exercise if prescribed
• Annual influenza vaccine and COVID-19 vaccine as recommended; pneumococcal vaccine per schedule
• RSV prevention: ask about infant antibody or maternal vaccine; hand washing, avoid sick contacts and crowds in RSV season, no smoke exposure
• Bronchiolitis at home: suction before small, frequent feeds; seek care for fast or labored breathing, pauses in breathing, poor feeding, fewer than half the usual wet diapers, or blue color
• Complete the full antibiotic course for pneumonia

• First action for a child in respiratory distress: SpO₂ and oxygen
• Bronchiolitis (RSV, under 2 years): supportive care — nasal suction, hydration, oxygen if SpO₂ below 90%; no albuterol, steroids, antibiotics, or chest physiotherapy
• Continuous SpO₂ monitoring for infants who are on oxygen or unstable
• RSV: contact precautions, cohorting, hand hygiene
• Prevention: nirsevimab or clesrovimab for infants under 8 months, or maternal RSV vaccine
• Pneumonia: tachypnea is the most sensitive sign; localized fine inspiratory crackles; judge antibiotic response by clinical improvement at 48–72 hours
• Postural drainage: affected lobe uppermost — right lower lobe (lateral) = head down, lying on the left side
• Asthma: ICS-containing treatment for all children 6–11 (no SABA-only); reliever before ICS; rinse and spit after ICS
• Acute asthma: repeated SABA + early systemic steroid; silent chest = emergency
• Montelukast boxed warning: neuropsychiatric effects
• Tepid sponging is not recommended for fever