Newborn Sepsis

Newborn sepsis rarely announces itself with fever — the subtlest behavioral changes you almost dismiss are often the only warning before rapid deterioration.

Neonatal sepsis is a systemic infection occurring in the first 28 days of life, classified as early-onset (within 72 hours, typically from vertical transmission — Group B Streptococcus, E. coli) or late-onset (after 72 hours, often nosocomial or community-acquired). The hallmark challenge is that signs are nonspecific and subtle: temperature instability (hypothermia more common than fever), poor feeding, lethargy or irritability, tachypnea or apnea, tachycardia or bradycardia, pallor or mottled skin, and hypoglycemia. Neonates are immunologically immature — they lack opsonizing antibodies and have an underdeveloped complement system, so infection disseminates rapidly. Risk factors include prolonged rupture of membranes (≥18 hours), maternal fever or chorioamnionitis, prematurity, and inadequate intrapartum GBS prophylaxis. Nursing priorities center on early recognition through trending vital signs, assessing feeding behavior, and promptly reporting any clinical change. Blood cultures are obtained before antibiotics are initiated, and empiric broad-spectrum antibiotics are started immediately — for early-onset sepsis, typically ampicillin plus gentamicin; for late-onset, coverage often includes vancomycin plus an aminoglycoside to target nosocomial organisms. Delays worsen outcomes significantly. A CBC with differential showing elevated or depressed WBCs, elevated immature-to-total neutrophil ratio (I:T ratio >0.2), and elevated CRP support the diagnosis.

Key Distinctions

Don't confuse newborn sepsis with respiratory distress syndrome — both cause tachypnea, but sepsis adds temperature instability, feeding intolerance, and lethargy not seen with isolated RDS. Students assume neonatal sepsis presents with fever; hypothermia is actually more common and more ominous. The I:T ratio >0.2 signals infection even when total WBC appears normal — don't dismiss it.

Clinical Pearl

Think of the septic newborn as the baby who "just doesn't look right" — hypothermia, not fever, is the red flag that separates neonatal sepsis from what you learned in adult med-surg.