What is the recommended treatment for a 7-month-old baby with bacterial pneumonia, elevated C-reactive protein (CRP) level, cough, and shortness of breath?

Treatment of Bacterial Pneumonia in a 7-Month-Old Infant

For a 7-month-old infant with bacterial pneumonia, elevated CRP, cough, and shortness of breath, hospitalization with intravenous ampicillin (150-200 mg/kg/day divided every 6 hours) or penicillin G (100,000-250,000 units/kg/day every 4-6 hours) is the definitive first-line treatment if the child is fully immunized. 1, 2

Immediate Assessment and Hospitalization Criteria

This infant requires hospital admission based on multiple indicators 3:

• Shortness of breath (difficulty breathing) is an absolute indication for hospitalization in infants 3
• Elevated CRP in the context of bacterial pneumonia suggests significant infection 4, 5
• Age under 18 months places the child at higher risk for complications 3

Additional criteria to assess for admission include 3:

• Oxygen saturation <92% or presence of cyanosis
• Respiratory rate >70 breaths/min
• Intermittent apnea or grunting
• Poor feeding

Initial Diagnostic Workup

Before initiating antibiotics, obtain 3, 2:

• Blood cultures (mandatory in all children with suspected bacterial pneumonia) 3
• Nasopharyngeal aspirate for viral antigen detection (required in all children under 18 months) 3
• Chest radiography to confirm pneumonia and assess for complications 3

First-Line Antibiotic Treatment

For Fully Immunized Infants (Low-Risk)

Intravenous ampicillin 150-200 mg/kg/day divided every 6 hours is the preferred treatment 1, 2. Alternative options include 1, 2:

• Penicillin G 100,000-250,000 units/kg/day IV every 4-6 hours 1
• Ceftriaxone 50-100 mg/kg/day IV every 12-24 hours as an alternative 1, 2, 6

For Not Fully Immunized or High-Risk Infants

If the infant is not fully immunized against Haemophilus influenzae type b or Streptococcus pneumoniae, use 3, 1:

• Ceftriaxone 50-100 mg/kg/day IV or cefotaxime 150 mg/kg/day IV every 8 hours 3, 1
• Add vancomycin 40-60 mg/kg/day every 6-8 hours or clindamycin 40 mg/kg/day every 6-8 hours if MRSA is suspected 3, 1

Supportive Care Management

Oxygen Therapy

• Administer supplemental oxygen if saturation is ≤92% to maintain oxygen saturation >92% 3
• Use nasal cannulae, head box, or face mask 3
• Monitor oxygen saturation at least every 4 hours 3

Fluid Management

• Intravenous fluids at 80% of basal requirements if needed 3
• Monitor serum electrolytes 3
• Avoid nasogastric tubes in severely ill infants as they may compromise breathing 3

What NOT to Do

• Do not perform chest physiotherapy - it is not beneficial and should not be used 3
• Avoid excessive handling to reduce metabolic and oxygen requirements 3

Clinical Interpretation of Elevated CRP

The elevated CRP in this 7-month-old infant supports bacterial pneumonia 4, 5:

• CRP >80 mg/L combined with clinical signs has high specificity for bacterial pneumonia 4, 5
• Peak CRP values in bacterial infections typically occur on days 2-4 of illness 7
• High CRP values (>80 mg/L) combined with elevated WBC count provide specificity >85% for bacterial pneumonia 5

Monitoring and Reassessment

Reassess within 48-72 hours for clinical improvement 8, 2. Signs of treatment failure include 2:

• Persistent or worsening fever
• Worsening respiratory distress
• Development of complications (pleural effusion, empyema)

If treatment failure occurs 2:

• Obtain repeat blood cultures
• Consider pleural fluid sampling if effusion develops 3
• Switch to broader-spectrum coverage or add vancomycin/clindamycin for MRSA coverage 1, 2

Special Considerations for MRSA

Add vancomycin or clindamycin if any of the following are present 1, 2:

• Severe presentation with necrotizing infiltrates
• Empyema or significant pleural effusion
• Recent influenza infection
• Failure to improve on initial therapy

Critical Pitfalls to Avoid

• Do not use oral antibiotics in this hospitalized infant with respiratory distress - IV therapy is mandatory 3
• Do not use macrolides as first-line therapy - atypical pathogens (Mycoplasma, Chlamydophila) are uncommon in children under 5 years 1, 8
• Do not underdose antibiotics - ensure full weight-based dosing 1
• Do not delay hospitalization - infants with shortness of breath require immediate admission 3