INFECTION
Neonatal Sepsis
A practical guide for paediatric registrars · Early- and late-onset neonatal sepsis
TREAT EARLY,
ASK QUESTIONS LATER
Exposure
Organisms are acquired before or during birth (early-onset - ascending or intrapartum) or later from the environment, lines or community (late-onset).
Vulnerable host
The newborn immune system is immature - weak barriers, low immunoglobulin and blunted responses - so organisms invade easily.
Bacteraemia and seeding
Organisms enter the bloodstream and may seed the lungs, meninges, bones or joints.
Dysregulated inflammation
A cytokine response drives vasodilation, capillary leak and poor perfusion.
Septic shock
Hypotension, metabolic acidosis, DIC and multi-organ dysfunction.
CLINICAL FINDINGS
- Temperature instability - low or high
- Respiratory distress, grunting or apnoea
- Tachycardia or bradycardia
- Poor perfusion, prolonged capillary refill, mottling
- Poor feeding, vomiting, abdominal distension
- Lethargy, irritability or hypotonia
- Hypo- or hyperglycaemia; jaundice
- The baby who is "just not right"
INVESTIGATIONS
- Blood culture before antibiotics
- FBC: neutropenia or neutrophilia, I:T ratio, thrombocytopenia
- CRP - serial trend is more useful than a single value
- Blood gas and lactate; glucose
- Lumbar puncture if meningitis suspected, culture positive or baby unwell
- Urine culture in late-onset; CXR if respiratory signs
COMPLICATIONS & RED FLAGS
- Septic shock and DIC
- Meningitis - bulging fontanelle, seizures
- Apnoea
- Petechiae, purpura, sclerema
- Red flags: rapidly rising lactate, shock or apnoea - escalate and treat now
MANAGEMENT
Treat first, confirm later: cultures then prompt empirical antibiotics and supportive care, de-escalating once the cultures and clinical course allow.
Recognise & screen
- Have a low threshold. Take a blood culture, then a full sepsis screen.
- In well term / late-preterm babies, a structured risk assessment (risk factors + exam ± EOS calculator) guides who needs screening.
- Do not delay antibiotics for investigations if sepsis is suspected.
Empirical antibiotics
- Start promptly after cultures, per local guideline.
- EOS is commonly benzylpenicillin (or ampicillin, which also covers Listeria) + gentamicin; broaden for meningitis.
- LOS cover is broader per unit; add antifungal cover if indicated.
- Review at 36-48h: stop if cultures are negative and the baby is well; 7-10 days if confirmed, longer for meningitis.
Supportive care
- Respiratory support to target saturations
- Fluids and inotropes for shock; maintain perfusion
- Maintain glucose and temperature; treat DIC; minimal handling
- Monitor closely and update the family
- Frequent observations; recognise subtle deterioration - perfusion, tone, feeding, colour and temperature.
- Take cultures first where possible, then give antibiotics promptly and on time.
- Meticulous hand hygiene and line care to prevent late-onset sepsis.
- Supportive care; escalate any deterioration and update the family.
How do you decide who needs a sepsis screen and antibiotics versus observation?
What is your unit's empirical regimen for early- and late-onset sepsis, and when do you stop?
How does the EOS calculator change management in well term babies?
When would you perform a lumbar puncture?
Take-home message: Neonatal sepsis is non-specific and can move fast. Because you cannot reliably exclude it on clinical grounds, take a blood culture and start empirical antibiotics early in any baby you are worried about, then reassess at 36-48h and stop if cultures are negative and the baby is well. Separate early-onset (vertical - GBS, E. coli, Listeria) from late-onset, support breathing and perfusion, and know your local antibiotic guideline.
For educational purposes only. Always align management to current guidelines and your local SCN/NICU or NETS protocols.