What is the initial approach to treating lower respiratory infections in children?

Initial Approach to Treating Lower Respiratory Infections in Children

The initial approach to treating lower respiratory infections in children depends on distinguishing viral bronchiolitis (which requires only supportive care) from bacterial pneumonia (which requires antibiotics), with amoxicillin as first-line therapy for community-acquired bacterial pneumonia. 1, 2

Immediate Clinical Assessment

Determine severity and need for hospitalization based on these specific criteria:

• Admit to hospital if: oxygen saturation <92%, difficulty breathing, inability to maintain oral hydration, age <60 days, grunting, apnea, altered mental status, or poor feeding 3, 1, 4
• Outpatient management acceptable if: child maintains adequate hydration, normal respiratory effort, and oxygen saturation ≥92% on room air 4, 5
• Re-evaluate within 48 hours if symptoms persist or worsen, as this may indicate treatment failure or complications 6, 7

Distinguish Viral from Bacterial Infection

Most lower respiratory infections in children are viral (90%) and do not require antibiotics: 1

• Viral bronchiolitis (typically RSV): presents with 2-4 days of upper respiratory symptoms (rhinorrhea, congestion, fever) followed by cough, wheezing, and increased respiratory effort 4, 8, 9
• Bacterial pneumonia: presents with fever, cough, respiratory distress, and may have focal findings on examination 1
• Routine chest radiography and viral testing are not necessary for diagnosis in most cases 8, 9

Treatment Algorithm

For Viral Bronchiolitis (Supportive Care Only)

Do not use antibiotics, corticosteroids, or routine bronchodilators for viral bronchiolitis: 8, 9

• Maintain oxygen saturation >92% with supplemental oxygen via nasal cannula if needed 3, 8
• Ensure adequate hydration: use nasogastric or intravenous fluids if oral intake is insufficient 8, 9, 5
• A single trial of bronchodilator (albuterol) is acceptable for wheezing, but discontinue if no prompt favorable response 4
• Avoid chest physiotherapy, hypertonic saline, epinephrine, and antibiotics as they provide no benefit 8, 9

For Bacterial Pneumonia (Antibiotic Therapy Required)

First-line antibiotic for community-acquired pneumonia:

• Amoxicillin 45 mg/kg/day divided every 12 hours (or 40 mg/kg/day divided every 8 hours) for 10 days 1, 2
• This covers Streptococcus pneumoniae, the most common bacterial pathogen 6, 2

If atypical bacteria suspected (Mycoplasma pneumoniae or Chlamydia pneumoniae, more common in children >5 years):

• Add a macrolide (azithromycin or clarithromycin) for at least 14 days 1
• Consider macrolide as first-line if clinical picture strongly suggests atypical pathogen 1

Alternative antibiotics if amoxicillin not suitable:

• Amoxicillin-clavulanate 80 mg/kg/day (amoxicillin component) 1
• Oral cephalosporins: cefuroxime axetil or cefpodoxime proxetil 1

For Severe Pneumonia Requiring Hospitalization

Intravenous antibiotic therapy is indicated when:

• Child cannot absorb oral antibiotics due to vomiting 3
• Severe signs present (respiratory distress, hypoxemia, altered mental status) 3

Recommended IV regimen:

• Ampicillin-sulbactam IV plus azithromycin IV to cover both typical and atypical organisms 3
• Alternative: cefuroxime IV or cefotaxime IV 3
• Minimum 3 days IV therapy, then transition to oral when clinically improved (afebrile, tolerating oral intake, improved work of breathing) 3

Additional inpatient management:

• IV fluids at 80% maintenance to prevent SIADH, with daily electrolyte monitoring 3
• Elevate head of bed 30-45 degrees 3
• Gentle nasal suctioning as needed 3
• Blood culture before starting antibiotics 3

Reassessment and Treatment Failure

Reassess after 48-72 hours of antibiotic therapy: 7, 1

• If no improvement or worsening: consider treatment failure, complications (parapneumonic effusion/empyema), or atypical pathogens 6, 7
• Do not change antibiotics within first 72 hours unless clinical deterioration occurs 1
• If amoxicillin fails: switch to amoxicillin-clavulanate or add macrolide for atypical coverage 1

Warning signs requiring urgent re-evaluation:

• Hypothermia (not just persistent fever) may indicate overwhelming sepsis or shock 7
• Persistent fever or illness at 48 hours requires exclusion of parapneumonic effusion/empyema with ultrasound 6, 7

Special Populations

For children with severe neurological impairment:

• Aminopenicillin plus beta-lactamase inhibitor for community-acquired LRTI 10
• Piperacillin-tazobactam for those with chronic lung disease or tracheostomy 10

For infants at high risk of severe RSV (born <35 weeks gestation, chronic lung/cardiac disease):

• Consider palivizumab prophylaxis during RSV season (November-April) 4, 9

Common Pitfalls to Avoid

• Do not prescribe antibiotics for viral bronchiolitis simply because the child appears ill—90% of lower respiratory infections are viral 1, 8
• Do not continue bronchodilators if no prompt response after initial trial 4
• Do not assume hypothermia means improvement—it may signal septic shock requiring immediate escalation of care 7
• Do not delay hospitalization for infants <60 days with any lower respiratory infection, as they are at highest risk 3, 4