20.5 Neonatal Sepsis

Neonatal sepsis results from a bacterial, fungal, or viral infection that affects the infant’s entire body and can result in severe morbidity and mortality, especially in preterm infants. Infection may be transmitted from the mother, such as a Group B strep infection, or it may be a healthcare-associated infection, such as pneumonia resulting from intubation. Early-onset neonatal sepsis occurs within 3 to 7 days of birth, late-onset neonatal sepsis occurs after the first week of life up to the first month of life, and very late-onset neonatal sepsis occurs in infants who have been in the NICU beyond their first month of life.^[1]

Multiple factors place a newborn at higher risk for neonatal sepsis. These factors are summarized in Table 20.5.

Table 20.5. Risks for Neonatal Sepsis^[2]

Signs and Symptoms

Neonatal infection can occur without noticeable signs of infection. Furthermore, neonates are more likely to have hypothermia rather than a fever due to their lack of ability to shiver. Signs of infection, if present, often manifest in the respiratory system with increased work of breathing, tachypnea, apnea, and central cyanosis. Cardiovascular signs of infection include tachycardia or bradycardia, poor peripheral circulation, extended capillary refill times, and hypotension. Generalized gastrointestinal signs of infection include poor feeding, vomiting, diarrhea, abdominal distention, and jaundice. Skin signs of infection, such as petechiae or purpura, may occur. The newborn with an infection may also be inactive, irritable, or lethargic.^[3]

Neonatal sepsis is diagnosed based on positive culture results, such as blood, cerebrospinal, or pleural culture. For blood cultures to determine sepsis, blood must be collected prior to antibiotic administration with two samples obtained from two different anatomic sites. Cerebrospinal fluid culture is recommended in newborns under 21 days of age who have had a positive blood culture and are suspected to have meningitis. Neonates who require intubation due to respiratory distress typically have tracheal aspirate sent for pleural culture. Additional laboratory work includes a complete blood count (CBC) with differential that includes white blood cells (WBCs), red blood cells to hematocrit ratio, platelets, and number of neutrophils (immature WBCs). However, nurses and health care providers are aware that newborn CBCs collected within 72 hours of birth reflect more about the mother’s immune status rather than serving as a biomarker for neonatal sepsis.^[4]

Nursing Management

Antibiotics are started as soon as sepsis is suspected in an infant, but after blood samples for cultures are taken. Ampicillin and an aminoglycoside are typically prescribed to cover the most common causative bacteria in newborns, which include Group B Streptococcus, Escherichia coli (E. coli), and Listeria monocytogenes (L. monocytogenes). If the neonate is at risk of a healthcare-associated infection, they are typically treated with vancomycin and an aminoglycoside. However, aminoglycosides have poor central nervous system (CNS) penetration, and a third-generation cephalosporin is added if meningitis is suspected or confirmed. Listeria is a gram-positive bacterium that can infect newborns from maternal transmission and is treated with penicillin.^[5]

Neonates treated with antibiotics should show improvement within the first two days and are usually culture negative by Day 3. Intravenous antibiotic therapy may be modified based on culture and sensitivity results and is typically ongoing for 7 to 10 days, although meningitis adds to the length of antibiotic treatment.^[6]