Epidemiology and risk stratification of young infants presenting to the emergency department with hypothermia

Objective

Hypothermic infants are presumed to be at high risk for a serious bacterial infection (SBI) or herpes simplex virus (HSV) infection. In contrast to febrile infants, the emergency department (ED) management of hypothermic infants is variable in the absence of consensus guidelines, potentially resulting in low-value care and missed diagnoses. We investigated the diagnostic workup conducted for hypothermic infants in our academic pediatric ED, the incidence of SBI and HSV infection, and risk factors associated with infection.

Methods

We conducted a single-center retrospective study of infants ≤90 days of age with a rectal temperature ≤36.5°C in the ED between 2013 and 2022. From their medical records, we abstracted the type(s) of testing each infant received in the ED and the diagnosis of SBI and HSV, analyzing characteristics associated with each.

Results

Of 1095 hypothermic infants identified, 402 (37%) underwent testing for SBI or HSV. Among these, 34/402 (8.5%) had an SBI or HSV. A minimum temperature below 36°C and hospital admission were characteristics associated with higher rates of infectious testing. Infants aged 29‒90 days, compared to 0‒28 days, were more likely to have a urinary tract infection (odds ratio 3.28, 95% confidence interval 1.47‒7.32).

Conclusions

Hypothermic infants have slightly lower rates of SBI or HSV than febrile infants, for whom infectious studies are widely recommended, but still high enough to warrant an infectious workup in most cases. Further research is required to risk stratify hypothermic infants in the ED to standardize care and improve outcomes while optimizing resource utilization.