Septicaemia in the neonate/child

Question 1

Define neonatal sepsis and the two categories.

Answer 1

Neonatal sepsis occurs when a serious bacterial or viral infection in the blood affects babies within the first 28 days of life.

Neonatal sepsis is categorised into:

1. early-onset (EOS, within 72 hours of birth) and
2. late-onset (LOS, between 7-28 days of life) sepsis,

…with each category tending to have a distinct group of causes and common presentations.

Question 2

What is the epidemiology of neonatal sepsis? What percentage of live births are affected?

Answer 2

• Neonatal sepsis accounts for 10% of all neonatal mortality
• Male:female 1:1
• Affects 1-5 per 1000 live births
• Term neonates: 1-2 per 1000 live births
• Late pre-term infants: 5 per 1000 live births
• Birth weight <2.5kg: 0.5 per 1000 live births
• Black race is an independent risk factor for group B streptococcus-related sepsis

Question 3

Which patohgens are mainly responsible for sepsis?

Answer 3

OVERALL two thirds of cases are due to:

• GBS
• E coli

Question 4

Which pathogens are mainly responsible for early onset sepsis?

Answer 4

GBS (Group B streptococcus) in 75% - infective causes in early-onset sepsis are usually due to transmission of pathogens from the mother to the neonate during delivery

Question 5

Which pathogens are mainly responsible for late onset sepsis?

Answer 5

Late-onset sepsis usually occurs via the transmission of pathogens from the environment post-delivery, this is normally from contacts such as the parents or healthcare workers

Infective causes are more commonly coagulase-negative staphylococcal species such as

• Staphylococcus epidermidis,
• Gram-negative bacteria such as Pseudomonas aeruginosa, Klebsiella and Enterobacter,
• Fungal species

Question 6

What are the uncommon causes of sepsis in an infant?

Answer 6

• Staphylococcus aureus
• Enterococcus
• Listeria monocytogenes
• Viruses including herpes simplex and enterovirus

Question 7

Name 4 risk factors for neonatal sepsis.

Answer 7

• Mother with previous neonate with GBS, GBS colonisation on prenatal screening, intrapartum temperature >=38, membrane rupture >=18hrs or infection throughout pregnancy
• Premature baby (<37 weeks, make up 85% of cases)
• LBW (<2.5kg, make up 80% of cases)
• Maternal chorioamnionitis

Question 8

Describe the presentation of neonatal sepsis.

Answer 8

Respiratory distress (85%)

• Grunting
• Nasal flaring
• Use of accessory respiratory muscles
• Tachypnoea
• Apnoea (40%)

Cardio:

• Tachycardia: common, but non-specific
• Temperature: not usually a reliable sign as the temperature can vary from being raised, lowered or normal
  
  • Term infants are more likely to be febrile
  • Pre-term infants are more likely to be hypothermic

Neuro:

• Apparent change in mental status/lethargy
• Seizures (35%): if cause of sepsis is meningitis

Abdo:

• Jaundice (35%)
• Poor/reduced feeding (30%)
• Abdominal distention (20%)
• Vomiting (25%)

Question 9

What investigations should you request for neonatal sepsis?

Answer 9

• Blood culture - 2 to prevent contamination
• FBC - neutrophilia?/neutropenia?
• CRP
• Blood gas - metabolic acidos with base deficit >=10mmol/L is concerning
• Urine MC&S - rarely positive in EOS, useful in LOS. May show leukocytes, culture, heaematuria, proteinuria if positive.
• Other:
  
  • Lumbar puncture if concern for meningitis (required by many hospitals if baby is <28 days and septic)

Question 10

What are the antibiotics of choice for suspected or confirmed neonatal sepsis?

Answer 10

• IV benzylpenicillin
• Gentamycin

This is usually given for 10 days, unless the culture and CRP(<10mg/L) are negative at 48 hrs.

Question 11

Apart from antibiotics, what does management of neonatal sepsis involve?

Answer 11

1. Maintain O2
2. Fluids and electrolytes - may require volume/vasopressor support in severe disease . Check body weight daily.
3. Manage/prevent hypoglycaemia
4. Manage/prevent metabolic acidosis