What is the approach for a lung examination on a 3-year-old?

Lung Examination Approach in a 3-Year-Old Child

In a 3-year-old child, perform lung examination using inspection, auscultation with a pediatric stethoscope, and assessment of respiratory rate and work of breathing, while pulmonary function testing with spirometry can be attempted but is only reliably achievable in children older than 3 years. 1

Physical Examination Components

Inspection and Observation

• Count respiratory rate for a full 60 seconds while the child is calm and quiet, as this is the most accurate method for detecting tachypnea (>40 breaths/min is abnormal at age 3). 2
• Assess for signs of respiratory distress including retractions (subcostal, intercostal, suprasternal), nasal flaring, and grunting. 2
• Observe chest wall movement for symmetry and signs of hyperinflation or paradoxical breathing. 3

Auscultation Technique

• Use a pediatric-sized stethoscope to listen systematically to all lung fields, comparing side-to-side. 4
• In structurally normal, healthy lungs with regular breathing, respiratory sounds should be relatively quiet with regular air movement along the trachea and bronchioles. 4
• Listen for abnormal breath sounds: wheezing suggests bronchiolitis or reactive airway disease, while crackles or decreased breath sounds suggest pneumonia. 5, 2
• Complete absence of breath sounds is a clinical emergency requiring immediate medical team assistance. 4

Supporting the Child During Examination

• Allow the child to become acquainted with the environment and examiner before starting, as fear can affect cooperation and breathing patterns. 1
• The child should be seated comfortably, and the examination should proceed in a calm, unhurried manner. 1

Pulmonary Function Testing Considerations

Feasibility at Age 3

• Spirometry can be reliably performed in children as young as 3 years of age, though success rates improve with age and experienced technicians. 1
• Under optimal conditions with trained personnel, most preschool children older than 3 years can successfully complete pulmonary function tests. 1
• Testing requires time, patience, and technicians specifically trained in working with young children who can help them perform at their best. 1

Practical Testing Options

• Simple spirometry should be performed in every patient who can complete the test, as it is relatively inexpensive, simple, and widely available. 1
• The interrupter technique and forced oscillation technique are feasible alternatives that require only tidal breathing and may be more successful in younger or less cooperative children. 1, 6
• Approximately 58-73% of 3-year-olds can produce acceptable forced expiratory maneuvers, though not all will meet strict adult-derived quality control criteria. 1

Clinical Decision-Making Based on Findings

When Wheezing Predominates

• Wheezing as the predominant finding suggests viral bronchiolitis rather than bacterial pneumonia, where crackles and decreased breath sounds would be more prominent. 5
• Provide supportive measures including oxygen if saturations <90-92%, hydration, and minimal handling. 5

When Additional Imaging is Needed

• Obtain chest x-ray if tachypnea is accompanied by crackles, decreased breath sounds, or signs of respiratory distress (retractions, grunting, nasal flaring). 2
• Do not perform chest radiography routinely in children with mild uncomplicated respiratory symptoms. 2

Monitoring Oxygen Status

• Use pulse oximetry to assess oxygenation, providing supplemental oxygen if SpO₂ drops below 92%. 7
• Transcutaneous oxygen monitoring can be used for continuous assessment in more severe cases. 3

Key Pitfalls to Avoid

• Do not rely on tachypnea alone (sensitivity 73.8%, specificity 76.8%, positive predictive value only 20.1% for pneumonia) without additional clinical findings. 2
• Avoid attempting pulmonary function testing during acute respiratory infection or when the child has abnormal auscultation, as baseline measurements require the child to be well. 1
• Do not use standard oronasal face masks for resistance measurements, as they add compliant compartments and prevent assessment of nasal versus oral contributions. 1