Sepsis Flashcards
What is the definition of neonatal sepsis?
Systemic bacterial infection documented by a positive blood culture
Early onset bacterial infection occurs in 1-2/1000 term infants and in up to 24% of very low birth weight infants.
What is the mortality rate for early onset sepsis in premature infants?
3% to 54%
The highest mortality rate is observed in very low birth weight infants.
What are the two categories of neonatal sepsis?
- Early onset sepsis
- Late onset sepsis
At what age does early onset sepsis present?
At or before 72 hours of age
85% present in the first 24 hours after birth.
How is early onset sepsis acquired?
- Vertical transmission from mother
- Aspiration of infected amniotic fluid
- During vaginal birth from bacteria colonizing mother’s lower genital tract
What are the most common organisms causing early onset neonatal sepsis?
- Group B Strep
- E. Coli
What is the age range for late onset sepsis?
From 72 hours to 7 days or later
How is late onset sepsis acquired?
From the care-giving environment
What are common nosocomial infection organisms in late onset sepsis?
- Coagulase negative Staph
- Pseudomonas
- Enterococcus
- E. Coli
- Enterobacter
What are maternal risk factors for neonatal sepsis?
- Malnutrition
- Sexually transmitted disease
- Periodontal disease
- Maternal colonization with Group B streptococcus
What increases the risk of infection in untreated mothers?
1%
Increased if there is preterm labor, maternal fever, or prolonged ruptured membranes.
What are neonatal risk factors for sepsis?
- Prematurity
- Low birth weight
- Male infant
- Meconium stained amniotic fluid
- Need for resuscitation
- Invasive procedures, lines, tubes
- Formula feeding
What environmental factors increase the risk of neonatal sepsis?
- Hospital/NICU admission
- Length of stay
- Transmission by caregivers
- Invasive procedures
- Indwelling catheters
- Skin breakdown
- Common use of broad spectrum antibiotics
- Use of histamine-2 blockers and proton pump inhibitors
Why are neonates at increased risk for infections?
- Decreased cytokine production
- Decreased antibody levels
- Poor response to antigen stimulation
- Fewer B cells recognize foreign antibodies
- Immature complement activity until ~6-10 months of age
What are common presentations of neonatal sepsis?
- Respiratory distress
- Apnea
- Lethargy
- Irritability
- Temperature instability
- Poor feeding
- Seizures or abnormal neurologic findings
- Jaundice
What are some localized infections associated with neonatal sepsis?
- Cellulitis
- Impetigo
- Omphalitis
- Conjunctivitis
- Soft tissue abscesses
What diagnostic tests are used to evaluate neonatal sepsis?
- CBC with differential
- Blood culture
- Urine culture
- CSF
- Tracheal aspirate
- Other inflammatory markers (e.g., CRP or procalcitonin)
What is the gold standard for diagnosing infection in neonatal sepsis?
Isolation of pathogen in a blood culture obtained using aseptic technique
What is the typical yield of urine cultures in early onset sepsis?
Low yield
What is the significance of Gram staining in identifying bacteria?
- Thick cell wall retains dye in Gram-positive bacteria
- Thinner cell wall in Gram-negative bacteria blocks antibiotics and dyes
What are common Gram-positive bacteria associated with neonatal sepsis?
- Streptococcus
- Staphylococcus
- Bacillus
- Clostridium
- Listeria
What is a major cause of perinatal bacterial infections?
Streptococcus Group B Beta hemolytic
What antibiotics are used to treat Streptococcus Group B Beta hemolytic infections?
- Ampicillin
- Gentamicin
What are common treatment options for Staphylococcus aureus infections?
- Nafcillin
- Oxacillin
- Vancomycin
- Clindamycin
