Pediatrics · Year 3 · from Pediatrics

Case 3: Neonatal Sepsis

Patient Demographics

  • Age: 18-hour-old female
  • Sex: Female

Chief Complaint

Newborn with temperature instability and poor feeding.

History of Present Illness

An 18-hour-old female newborn develops temperature instability with a rectal temperature of 38.2C noted on routine vital signs in the newborn nursery. The infant had been feeding well initially but has become increasingly lethargic and refused the last two feeds. The mother had prolonged rupture of membranes for 26 hours prior to delivery and received only one dose of ampicillin (4 hours before delivery) as GBS prophylaxis. Mother was GBS positive on prenatal screening. Delivery was at 38 weeks via vaginal delivery. Birth weight was appropriate for gestational age. APGAR scores were 8 and 9. The infant initially appeared well but nursery staff noted mottled skin color and tachypnea on most recent assessment.

Growth Parameters

  • Birth weight: 3.1 kg (35th percentile)
  • Length: 49 cm (35th percentile)
  • Head circumference: 33.5 cm (35th percentile)

Physical Examination

  • General: Ill-appearing, lethargic newborn with mottled skin
  • Vital signs: T 38.2C rectal, HR 185, RR 68, BP 52/30, SpO2 94% on room air
  • HEENT: Anterior fontanelle soft, flat
  • Cardiovascular: Tachycardia, weak peripheral pulses, capillary refill 4 seconds
  • Respiratory: Tachypnea, mild subcostal retractions, grunting, clear breath sounds
  • Abdomen: Mildly distended, decreased bowel sounds
  • Skin: Mottled, delayed capillary refill
  • Neurologic: Hypotonic, weak cry, poor suck

Workup

  • CBC: WBC 3,200/mcL (low), neutrophils 1,100/mcL, bands 24%, I:T ratio 0.35 (elevated), platelets 98,000/mcL
  • CRP: 45 mg/L (elevated)
  • Blood culture: Pending (obtained before antibiotics)
  • CSF (lumbar puncture):
  • WBC 85/mcL (75% neutrophils)
  • Protein 180 mg/dL (elevated)
  • Glucose 22 mg/dL (low; serum glucose 75)
  • Gram stain: Gram-positive cocci in chains
  • Culture: Pending
  • Urinalysis and culture: Obtained
  • Chest X-ray: Bilateral hazy infiltrates
  • Blood gas: pH 7.28, pCO2 38, HCO3 17 (metabolic acidosis)
  • Lactate: 5.8 mmol/L (elevated)

Diagnosis

Early-onset neonatal sepsis with meningitis, presumed Group B Streptococcus

Clinical Reasoning

This infant has multiple risk factors for early-onset sepsis: maternal GBS colonization with inadequate intrapartum prophylaxis (<4 hours before delivery) and prolonged rupture of membranes >18 hours. The clinical presentation of fever, lethargy, respiratory distress, poor perfusion, and laboratory findings of leukopenia with left shift, thrombocytopenia, elevated CRP, and abnormal CSF with gram-positive cocci strongly suggest GBS sepsis with meningitis. The presentation within 24 hours of birth is classic for early-onset sepsis.

Management

  1. Empiric antibiotics: Ampicillin 150 mg/kg IV q8h + Gentamicin 4 mg/kg IV q24h (meningitis dosing)
  2. Fluid resuscitation: 20 mL/kg NS bolus, repeat as needed for perfusion
  3. Respiratory support: Supplemental oxygen, escalate to CPAP or mechanical ventilation if needed
  4. NPO and IV fluids: TPN if prolonged course anticipated
  5. Supportive care:
  • Monitor glucose closely
  • Correct metabolic acidosis
  • Blood pressure support with dopamine if fluid refractory
  1. Repeat lumbar puncture: In 24-48 hours to document sterilization
  2. Duration of antibiotics:
  • If cultures confirm GBS meningitis: 14-21 days
  • Repeat CSF at end of therapy
  1. Hearing screen: Before discharge (GBS meningitis associated with hearing loss)
  2. Neurodevelopmental follow-up: Long-term monitoring for sequelae

Clinical Image

Image Description: Gram stain of cerebrospinal fluid demonstrating gram-positive cocci in chains consistent with Group B Streptococcus.

Source: CDC Public Health Image Library URL: https://phil.cdc.gov/Details.aspx?pid=2471 License: Public Domain

All cases for this lecture as Markdown