Sepsis Evaluation in Febrile Neonates

Mandatory Diagnostic Studies

Blood culture is required for every febrile infant ≤ 28 days of age, regardless of clinical appearance, because bacteremia occurs in approximately 1–4.5 % of this population (American Academy of Pediatrics guideline) 1
Lumbar puncture with cerebrospinal fluid cell count is mandated for all febrile infants ≤ 21–28 days according to the AAP, and the guideline advises hospitalization if CSF cannot be obtained or is uninterpretable 1
Urinalysis (with urine culture obtained by catheterization or suprapubic aspiration) is a required component of the complete sepsis work‑up; urinary tract infections account for about 14 % of serious bacterial infections in neonates (AAP recommendation) 1
Urinary tract infection is the most common bacterial infection in febrile young infants, with a prevalence of roughly 8–13 % (American College of Radiology data) 2

Chest radiography is optional in a well‑appearing febrile neonate who lacks respiratory symptoms; routine imaging is not supported by the ACR Appropriateness Criteria for infants ≤ 3 months without localizing respiratory findings 2
Pneumonia is identified in only 1–3 % of febrile infants ≤ 3 months, and the prevalence is even lower when no respiratory signs are present (ACR data) 2

In a 6‑day‑old infant with fever, hypotension, and tachycardia, a full sepsis evaluation—including blood culture, lumbar puncture, and urinalysis—should be performed, followed by empiric broad‑spectrum antibiotics and admission for observation (AAP guideline) 1