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
What is the treatment for Listeria monocytogenes infections?
- Ampicillin
- Gentamicin
What is the initial empiric antibiotic therapy for early onset sepsis?
- Ampicillin
- Aminoglycoside (e.g., Gentamicin)
What is the recommendation for screening women for GBS?
Universal screening at 35-37 weeks
What should be done for newborns with signs of sepsis?
Receive a full diagnostic workup including CBC and differential, blood culture, and possibly a CXR or LP
What are the risk factors for neonatal HSV infection?
- Type of maternal infection (primary vs secondary)
- Maternal antibody status
- Mode of delivery (vaginal vs cesarean section)
- Duration of rupture of membranes
- Integrity of cutaneous barrier
What is the most common congenital viral infection?
CMV
What are some presentations of congenital CMV infection?
- IUGR
- Microcephaly
- Hepatosplenomegaly
- Petechial rash
- Chorioretinitis
- Thrombocytopenia
- Neutropenia
- Direct hyperbilirubinemia
What is the leading cause of hearing loss and neurodevelopmental impairment?
CMV
CMV stands for Cytomegalovirus.
How is CMV transmitted?
Transplacentally, perinatally via cervical or vaginal secretions, or breast milk
These routes highlight the various ways CMV can be passed from mother to child.
What percentage of US live births are affected by congenital infection?
0.5% to 1.5%
This statistic indicates the prevalence of congenital CMV infection in the United States.
Name three clinical presentations of CMV infection.
- IUGR
- Microcephaly
- Hepatosplenomegaly
IUGR stands for Intrauterine Growth Restriction.
What are two additional symptoms associated with CMV?
- Petechial rash
- Chorioretinitis
Chorioretinitis refers to inflammation of the choroid and retina of the eye.
What hematological conditions can occur due to CMV infection?
- Thrombocytopenia
- Neutropenia
Thrombocytopenia is a condition characterized by low platelet count, while neutropenia refers to low levels of neutrophils.
What type of hyperbilirubinemia is associated with CMV?
Direct hyperbilirubinemia
This condition indicates an increase in direct bilirubin levels in the blood, often due to liver dysfunction.
Should all infants presenting with signs of CMV be screened?
Yes
Screening is particularly important for those showing signs of infection.
What is a recommended treatment for CMV that shows a decrease in neurological sequelae?
Ganciclovir
Ganciclovir is an antiviral medication used to treat CMV infections.
Should all IUGR/SGA infants be screened for CMV?
Yes
IUGR stands for Intrauterine Growth Restriction, and SGA stands for Small for Gestational Age.
