Early- and late-onset neonatal sepsis — Rapid

Synopsis

Recognise subtle neonatal infection, integrate maternal risk with clinical indicators, obtain cultures without delaying treatment, prescribe age- and setting-appropriate IV antibiotics, and review them at 36 or 48 hours using NICE criteria.

Early-onset infection presents within 72 hours of birth in the NICE pathway and is commonly vertically acquired; late-onset infection begins from 72 hours onward.
Neonatal sepsis is often nonspecific: altered behaviour, poor feeding, temperature instability, respiratory change, apnoea, jaundice, glucose instability or abdominal signs may precede collapse.
Use NICE risk factors and clinical indicators systematically. Any red-flag indicator, or two or more non-red-flag factors or indicators, usually triggers investigation and empirical antibiotics.
Obtain blood culture before the first dose whenever possible, but never delay antimicrobials in an unwell baby. Give antibiotics within 1 hour of the treatment decision.
First-line early-onset empirical treatment is IV benzylpenicillin 25 mg/kg every 12 hours plus gentamicin 5 mg/kg, with the next gentamicin dose usually 36 hours later and guided by levels.
Consider benzylpenicillin every 8 hours when the baby appears very ill. Doses and intervals must follow gestation, age, renal function and the current neonatal formulary.
For suspected late-onset infection in a neonatal unit, NICE recommends a narrow-spectrum combination such as IV flucloxacillin plus gentamicin, modified by local surveillance.
If meningitis is suspected and the organism is unknown, NICE recommends IV amoxicillin plus cefotaxime. Perform lumbar puncture when safe without delaying treatment.
Measure baseline CRP and repeat 18–24 hours after presentation. A single low CRP cannot exclude infection; trajectory and clinical course support review.
Consider stopping early-onset antibiotics at 36 hours and late-onset antibiotics at 48 hours only when culture is negative, initial suspicion was not strong, the baby is clinically reassuring and CRP trend is reassuring.
Treat a positive blood culture or strongly suspected sepsis without meningitis for 7 days in most cases; extend for pathogen, site, recovery or microbiology advice.
Source control matters: remove or replace an infected line when indicated, drain collections and investigate focal bone, joint, urinary, skin or abdominal infection.

Key red flags

Apnoea, grunting, increasing oxygen need, shock, mottling, poor perfusion or hypotension may be the only early sign of invasive infection.

Seizure, bulging fontanelle, abnormal tone, reduced responsiveness or unexplained temperature instability raises meningitis and requires an appropriate CNS-penetrating regimen.

Rapidly spreading non-blanching rash, bleeding or severe thrombocytopenia raises disseminated infection and coagulopathy.

Bilious aspirate, marked abdominal distension, blood in stool or abdominal discoloration raises necrotising enterocolitis with or without sepsis and requires feeds to stop.

Maternal fever, clinical chorioamnionitis, invasive group B streptococcal infection in a previous baby or prolonged membrane rupture materially alters early-onset risk.

Central-line infection, focal skin or joint findings, poor feed tolerance or a new apnoea cluster in a neonatal-unit infant can be late-onset infection despite subtle systemic signs.

Investigation priorities

First-line: blood culture before antibioticsFirst stepFirst line

Identify bacteraemia and guide narrow definitive treatment.

Reference standard for meningitis: CSF microscopy, protein, glucose, culture and PCRReference standard

Confirm CNS infection and define organism and duration.

Management branches

Early onsetRisk and indicator decision

The baby is within 72 hours of birth.

Identify red flags and count other NICE risk factors and clinical indicators.
With any red flag or at least two factors/indicators, culture and treat without waiting; with only one non-red-flag item, use clinical judgement and monitor for at least 12 hours if not treating.
Reassess immediately if a new indicator emerges.

Key medicines

Benzylpenicillin intravenousFor empirical early-onset infection, 25 mg/kg IV every 12 hours; consider every 8 hours when the newborn appears very ill. Pair with gentamicin and use the current neonatal formulary for gestation, age and renal modifiers.Check allergy, renal function and exact weight. This empirical dose is not the meningitis dose. Review at 36 hours and narrow or stop only when NICE criteria are met.

Gentamicin intravenous5 mg/kg IV for empirical neonatal infection. NICE advises the second dose usually 36 hours later in early-onset treatment; all subsequent timing follows concentration monitoring, gestation, postnatal age, renal function and the neonatal formulary.Obtain and act on levels, monitor creatinine and urine output, and avoid concurrent nephrotoxic or ototoxic exposure where possible. Interval errors are dangerous; do not default to adult schedules.

Open full textbook →Answer 2 questions