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Antibiotics - for neonatal sepsis

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  • Bacterial sepsis is a major problem in the newborn unit.
  • The incidence of sepsis is higher in preterm infants, especially the very low birthweight infant (<1500g).
  • Common organisms identified are coagulase negative Staphylococci, Staphylococcus aureus, Streptococcus agalactiae (Group B Streptococcus) and Escherichia coli.
  • Other important pathogens include Listeria monocytogenes, Streptococcus pneumoniae, Haemophilus influenza and other Gram-negative organisms.
  • The clinical presentation of sepsis in the newborn is often non-specific; however, there may be an acute deterioration. 

Classification of Neonatal Sepsis

Early Onset Sepsis
(infection occurring in the first 5 days of life)

Late Onset Sepsis 
(infection occurring after 5 days of age)

Exposure to bacteria can occur:
  • Before delivery due to infected amniotic fluid or occasionally following maternal sepsis. 
  • During delivery when contact with organisms in the vagina can occur. 
  • After delivery following exposure to organisms in the infants environment. 
Usually due to:
  • Nosocomial infection, organisms acquired from the environment.
  • Coagulase negative Staphylococci are the most common causative organisms. 
  • VLBW infants with indwelling catheters, central lines, chest drains etc are at particular risk.
  •  Antibiotics should be considered in any baby with signs of sepsis, particularly in the presence of risk factors.
  • Risk factors may be an indication for investigation but are not in themselves an indication for antibiotics if the baby is born at term and is clinically well.
  • If there are any doubts a senior member of staff should be consulted.

Risk factors for Sepsis

  • Prolonged rupture of membranes (>18 hours).
  • Prematurity (especially in association with PROM).
  • Preterm labour with no adequate explanation.
  • Fetal distress without adequate explanation (fetal heart rate abnormalities especially fetal tachycardia, passage of meconium).
  • Maternal fever or other evidence of infection.
  • Foul smelling amniotic fluid or malodorous baby.
  • Indwelling vascular catheter.

Signs of Sepsis in the Newborn

  • Fever, hypothermia and/or temperature instability.
  • Respiratory distress.
  • Apnoea and bradycardia.
  • Cyanotic episodes.
  • Tachycardia, hypotension.
  • Lethargy, irritability, poor feeding.
  • Unexplained high/low or unstable blood sugars.
  • Abdominal distension and bile-stained aspirates.
  • Unexplained jaundice.
  • Umbilical flare, skin rashes.

What Investigations should be performed?

  • Full blood count.
  • Differential white cell count (Normal WBC 10-30,000 x 109/L) and percentage left shift (immature neutrophils/total neutrophil count).
    • If >20% this is moderately predictive of sepsis.
    • A low WCC especially with neutropenia is also suspicious of sepsis.
  • Blood cultures.
  • Chest radiograph.
  • A C-Reactive Protein (CRP) may be indicated. CRP is most useful as a trend, rather than as a diagnostic marker.
  • On occasion, skin/wound swabs and (very rarely) gastric aspirate (at birth only).
  • CSF may be needed in some cases - discuss with specialist.

The following investigations may need to be considered depending on the organism isolated.

Early onset infection: LP is indicated if the organism is Group B strep or E coli or if infant severely unwell.

Late onset sepsis: In addition to the above consider

  • Blood culture taken through central line.
  • Lumbar puncture and CSF for microbiology/biochemistry.
  • Urine by suprapubic aspirate or catheter.

Antibiotic Use in Suspected Sepsis

First five days

After first five days

Start amoxycillin and gentamicin for all neonates. Start flucloxacillin and amikacin in all babies
  1. Almost all Coag negative Staphylococcus is sensitive to amikacin but resistant to gentamicin.
  2. Flucloxacillin is used at present because of an increased number of Staphylococcus aureus isolates within the unit.
Add amoxycillin if specific cover for Enterococci, Strep fecaelis (suspected NEC), Listeria or Group B Streptococcus is needed.
  • Review clinical progress and microbiology results at 36 hours.
    • If cultures negative consider stopping therapy.
    • Continue therapy if cultures positive or sepsis very likely.
  • Add metronidazole if suspicion of anaerobic infection (e.g. intra-abdominal sepsis, NEC). If abdominal infection/NEC beyond 5 days use amoxicillin in preference to flucloxacillin
  • Consider vancomycin for coagulase negative Staphylococcal sepsis, especially if infant unwell or central line infection with line staying in.  Discuss with specialist first.
  • Add cefotaxime if neonatal meningitis. Discuss with specialist first.
  • Consider cefuroxime or piptaz for ventilator-associated pneumonia

Duration of Treatment

Infection type

Duration (days) of therapy

Pneumonia 5-7
Septicaemia 7-10
Urinary Tract Infection 7-10
Meningitis 14-21 (depending on organism isolated)
Skin conditions 5
Conjunctivitis 5-7
Oral thrush 7-10

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Document Control

  • Date last published: 01 September 2017
  • Document type: Clinical Guideline
  • Services responsible: Neonatology
  • Owner: Newborn Services Clinical Practice Committee
  • Editor: Sarah Bellhouse
  • Review frequency: 2 years