Hypothermia in Young Infants: Frequency and Yield of Sepsis Work Up

OBJECTIVES Serious bacterial infections (SBIs) in young infants can present with fever or hypothermia. There are substantial data on fever as a presentation for SBI that help to inform the clinical approach. In contrast, data on hypothermia are lacking, thus leaving clinicians without guidance. We aimed to describe the workup and findings, specifically the occurrence, of SBIs in infants younger than 60 days of life with hypothermia. METHODS We reviewed the medical records of infants younger than 60 days of life with rectal temperature of less than 36.5°C upon arrival to a children's hospital emergency department between January 2013 and December 2014. Comparisons were made between those who were found to have an SBI and those without. Serious bacterial infection was defined as bacteremia, bacterial meningitis, pneumonia, or urinary tract infection (UTI). RESULTS From the 414 patients identified, 104 (25%) underwent a sepsis evaluation of blood, urine, and/or cerebrospinal fluid culture. Serious bacterial infections were identified in 9 patients: 4 with UTI, 1 with pneumonia, 2 with bacteremia, 1 with pneumonia and UTI, and 1 with meningitis and bacteremia. Compared with patients with negative cultures, patients with SBI were older and had elevated absolute band counts and elevated immature-to-total neutrophil ratio. CONCLUSIONS Approximately a quarter of infants younger than 60 days with hypothermia were evaluated for SBI. Serious bacterial infection was identified in 9% of evaluated infants (2% of all hypothermic infants). Hypothermia can be a presenting sign of SBI.