What is the emergency room protocol for a 1-month-old neonate presenting with fever?

Emergency Room Protocol for a 1-Month-Old with Fever

A 1-month-old infant (neonate) with fever ≥38.0°C (100.4°F) requires immediate hospitalization with full sepsis evaluation and empiric parenteral antibiotics started immediately after cultures are obtained. 1, 2

Immediate Actions Upon Arrival

Temperature Confirmation and Initial Assessment

• Document rectal temperature to confirm fever ≥38.0°C (100.4°F), as this is the gold standard for this age group 1, 2
• Assess for toxic appearance, respiratory distress, altered mental status, poor perfusion, petechial rash, or refusal to feed 2
• Critical pitfall: Do not rely on clinical appearance alone—only 58% of infants with bacteremia or bacterial meningitis appear clinically ill 1, 3

Mandatory Laboratory Evaluation ("Full Sepsis Workup")

Blood work:

• Blood culture (obtain BEFORE starting antibiotics—this is mandatory) 2
• Complete blood count with differential 1
• Inflammatory markers (C-reactive protein and/or procalcitonin) 1

Urine studies:

• Urinalysis and urine culture obtained by urethral catheterization (NOT bag collection, which has poor specificity) 2
• Catheterization has 95% sensitivity and 99% specificity 2

Cerebrospinal fluid analysis:

• Lumbar puncture with CSF analysis is essential and should be performed on all febrile neonates 1, 2
• Clinical examination cannot reliably exclude meningitis even in well-appearing infants at this age 2
• Send CSF for cell count, glucose, protein, Gram stain, bacterial culture, and consider enterovirus testing 2

Empiric Antibiotic Therapy

Start immediately after cultures are obtained (do not delay for imaging or subspecialty consultation): 2

• Ampicillin IV 150 mg/kg/day divided every 8 hours 2
• PLUS either:
  • Ceftazidime IV 150 mg/kg/day divided every 8 hours, OR 2
  • Gentamicin IV 4 mg/kg/dose every 24 hours 2

If meningitis is confirmed by CSF analysis:

• Increase ampicillin to 300 mg/kg/day divided every 6 hours 2
• Continue ceftazidime at the same dose 2

Disposition

Mandatory hospitalization in a unit with nurses and staff experienced in caring for young infants 2

Rationale for Aggressive Management

• Risk of invasive bacterial infection is 8-13% in infants under 3 months 1
• At 1 month of age, the immune system is relatively immature and cannot adequately fight serious bacterial infections 1, 2
• Urinary tract infections account for more than 90% of serious bacterial infections in this population 1, 4
• Bacterial meningitis remains a critical risk that cannot be excluded clinically 2

Monitoring and Follow-Up

• Monitor continuously for signs of clinical deterioration 2
• Antibiotics may be stopped only if ALL of the following criteria are met: 2
  • CSF analysis is normal or enterovirus-positive
  • Urinalysis is negative
  • All inflammatory markers are normal
  • Blood and CSF cultures remain negative at 48 hours

Critical Pitfalls to Avoid

• Never discharge a febrile neonate from the ED without full evaluation and admission 1, 2
• Do not assume recent antipyretic use means the infant is less sick—antipyretics can mask fever severity 1
• Do not assume a viral infection excludes bacterial infection—both can coexist 1, 3
• Never collect urine by bag method—use catheterization or suprapubic aspiration only 2
• Do not delay antibiotics while waiting for imaging, subspecialty consultation, or admission bed 2

Special Considerations

The American College of Emergency Physicians guideline excludes neonates from less aggressive management protocols, emphasizing that this age group requires the most comprehensive evaluation regardless of appearance 5. This differs from older infants (29-90 days) where some risk stratification may be possible 5.