Febrile Infant — IV and Laboratory Studies — Clinical Pathway: Emergency Department and Inpatient

Febrile Infant Clinical Pathway — Emergency Department and Inpatient

IV and Laboratory Studies

Blood
  • POC glucose as needed
  • CBC with differential and procalcitonin for infants 22-56 days
  • Blood culture
  • Blood HSV PCR as indicated
  • BMP or CMP as indicated
Urine Perform catheterization for UA and urine culture

Inflammatory Markers

  • The AAP Guidelines (2021) Recommend   procalcitonin (PCT) as the most accurate independent predictor of invasive bacterial infection and do not recommend use of abnormal WBC for risk stratification
  • PCT testing available: Use PCT and absolute neutrophil count (ANC) as IMs
  • PCT testing unavailable: Abnormal ANC or CRP, or a temperature
    > 38.5°C are considered IMs associated with increased risk for invasive bacterial infection
Inflammatory Marker (IM) Definition of Abnormal
Procalcitonin > 0.5 ng/mL
C-reactive protein > 2 mg/dL
Absolute neutrophil count > 4000 neutrophils/µL

Neutropenia

  • An ANC < 1000 should be interpreted in the appropriate clinical context
    • A recent multi-center study found ANC < 1000 was not associated with bacteriemia or bacterial meningitis, but due to the rare frequency of neutropenia, this needs future study
    • The AAP states that an ANC < 1000 should raise concerns for sepsis in febrile young infants; however, viral infections are a known cause of neutropenia

References