Commentary on New Guidelines for the Evaluation and Management of the Febrile Young Infant.

Abstract

I read the recent clinical practice guideline published in Pediatrics on the evaluation and management of well-appearing febrile young infant (FYI) with no evident focus of infection, ages 8 to 60 days.1 The guidelines endorse using nonspecific inflammatory markers (IMs) as surrogate identifiers for risk of invasive bacterial infections (IBIs) (bacteremia and bacterial meningitis).The Pediatric Emergency Care Applied Research Network (PECARN) study,2 which generated a low-risk criteria protocol, examined a total of 10 cases of bacterial meningitis. This is an inadequate sample for drawing reliable conclusions regarding diagnostic accuracy of IMs. Of note, researchers in a recently published study using these same low-risk criteria misidentified 10.2% with a serious bacterial infection, including 4 patients with bacteremia and 2 with bacterial meningitis.3If IMs are normal in the 3-to 4-week-old, lumbar puncture (LP)/cerebrospinal fluid (CSF) analysis is recommended as optional; if LP is not performed, treatment “may” include antibiotic administration. If an LP is performed subsequently during observation and after initiating antibiotics, the algorithm does not account for the condition of partially treated meningitis. If subsequent LP reveals CSF pleocytosis with a negative CSF culture result, the infant must be presumed to have partially treated meningitis and committed to a full course of antibiotic therapy. Yet, a pathway in the algorithm allows for discontinuing antibiotics and hospital discharge if all culture results are negative at 24 to 36 hours.The algorithm recommends no LP for a 29-day-old with normal IMs and positive urinalysis results. Yet, urinary tract infection (UTI) should be considered an “evident source of infection,” meeting exclusionary criteria for guideline applicability. Urosepsis is not uncommon in the FYI.4 Anecdotally, I recently managed a 7-week-old febrile infant meeting all low-risk criteria: well appearing, negative urinalysis result, normal serum procalcitonin and C-reactive protein levels, and normal complete blood cell and white blood cell count/absolute neutrophil count (ANC); and 24 hours later, the urine and blood cultures were positive for Citrobacter koseri (urosepsis).There should be zero tolerance for a missed IBI in the FYI. I would caution clinicians when considering relying on nonspecific IMs to act as surrogate in identifying IBI risk in the FYI.