Neonatal sepsis: Nursing

Neonatal sepsis refers to the presence of bacteria in the blood or bacterial meningitis presenting in the first 30 days of life. It is classified as early-onset and late-onset sepsis. Early-onset sepsis occurs during the first three days of life, and is caused by exposure to a pathogen during the intrapartum period; while late-onset sepsis occurs after the first week of life, and is caused by pathogens that are acquired postnatally.

Now, let’s quickly review the immune system of newborns. During the first six months of life, the immune system is immature, meaning that it reacts more slowly to an invasion when compared to older children. Because the infant’s immune system isn’t fully developed, they depend on the few antibodies acquired from the mother during the intrauterine life and from breast milk. These offer some protection but are too few to keep infections localized, so there’s a higher risk of infections spreading quickly throughout the body. Additionally, the newborn’s blood-brain barrier is underdeveloped, and that makes it easier for pathogens to enter the central nervous system and cause meningitis.

Now, neonatal sepsis is most commonly caused by bacteria from the mother’s genitourinary tract that infects the infant during delivery. The most common ones include group-B Streptococcus, Streptococcus pyogenes, Escherichia coli, Listeria monocytogenes, Haemophilus influenzae , Enterobacter spp. Less commonly, sepsis can be caused by fungi, such as Candida albicans.

Risk factors for neonatal sepsis are grouped into fetal and maternal risk factors. Fetal risk factors include prematurity, low birth weight, and admission to the neonatal intensive care unit, or NICU for short. On the other hand, maternal risk factors include prolonged rupture of membranes that lasts 12 to 18 hours prior to delivery, in addition to chorioamnionitis, and vaginal colonization by group-B Streptococcus.

Alright, now the pathological process of neonatal sepsis starts when a pathogen, say some bacteria, enters the body. With the immune system still immature and the immunoglobulin levels at a lower level, there’s a higher risk that some bacteria will make it into the bloodstream. At this point, the bacteria and the toxin they release can activate immune cells to release proinflammatory cytokines, which trigger widespread inflammation. These bacteria and toxins can also find their way to various body organs, and cause impaired pulmonary, hepatic, and renal function.