The index of suspicion for sepsis must be high in neonates because signs can be subtle and nonspecific, and there is serious risk for morbidity and mortality from this condition. Any ill-appearing neonate (infant in the first 28 days of life) must receive a full work up, including a CBC, UA, urine and blood cultures, and a lumbar puncture (LP).
In a neonate, a fever is any temperature greater than 100.4F. Since neonates do not have a fully developed immune system, they may not appear as ill as an older child or adult with sepsis. In particular, jaundice between days 3-7 of life in an ill-appearing infant is very concerning for sepsis.
Moerschel et al. discuss management of jaundice, which can be a benign physiologic process or can be a sign of a more serious underlying condition, including sepsis. They note that frequent feeding (8-12 times in 24 hours) is important for primary prevention while regular monitoring, risk stratification (including nomogram use), and prompt outpatient follow-up are important for secondary prevention.
Baker et al. undertook a prospective cohort study to examine whether screening criteria (Philadelphia criteria) used in older infants (1-2 months of age) could be applied to neonates with a fever of 100.4F or higher in the ED to stratify them by likelihood of having a serious bacterial infection (SBI). They found that 12.6% of these neonates had an SBI. In this population, the Philadelphia criteria lacked the negative predictive value and sensitivity to identify neonates at risk of having a SBI.
Illustration A demonstrates the subtlety of neonatal jaundice.
Answer 1: This evaluation for respiratory viruses is incomplete because it doesn't address potential bacterial causes and sources for the illness outside of the respiratory tract.
Answer 2: This neonate is toxic, and while supportive care is important, diagnostic evaluation to look for a source is also warranted.
Answer 4: A full septic workup must also include a urinalysis, urine and blood cultures and an LP. Further, sputum samples are often low-yield in infants and children, unless induced.
Answer 5: While antibiotics are urgent in ill neonates, the workup suggested is incomplete without a urinalysis and urine culture. Additionally, performing cultures of blood and cerebrospinal fluid after initiation of empiric antibiotics reduces the diagnostic yield of these studies.
Moerschel SK, Cianciaruso LB, Tracy LR. A Practical Approach to Neonatal Jaundice. Am Fam Physician. 2008 May 1;77(9):1255-1262.
PMID:18540490 (Link to Abstract)
Baker MD, Bell LM. Unpredictability of Serious Bacterial Illness in Febrile Infants From Birth to 1 Month of Age. Arch Pediatr Adolesc Med. 1999;153(5):508-511. doi:10.1001/archpedi.153.5.508.
PMID:10323632 (Link to Abstract)