Performance of Febrile Infant Decision Tools on Hypothermic Infants Evaluated for Infection.

BACKGROUND: Given the lack of evidence-based guidelines for hypothermic infants, providers may be inclined to use febrile infant decision-making tools to guide management decisions. Our objective was to assess the diagnostic performance of febrile infant decision tools for identifying hypothermic infants at low risk of bacterial infection. METHODS: We conducted a secondary analysis of a retrospective cohort study of hypothermic (≤36.0 C) infants ≤90 days of age presenting to the emergency department or inpatient unit among 9 participating sites between September 1, 2016 and May 5, 2021. Well-appearing infants evaluated for bacterial infections via laboratory testing were included. Infants with complex chronic conditions or premature birth were excluded. Performance characteristics for detecting serious bacterial infection (SBI; urinary tract infection, bacteremia, bacterial meningitis) and invasive bacterial infection (IBI; bacteremia, bacterial meningitis) were calculated for each tool. RESULTS: Overall, 314 infants met the general inclusion criteria, including 14 cases of SBI (4.5%) and 7 cases of IBI (2.2%). The median age was 5 days, and 68.1% of the infants (214/314) underwent a full sepsis evaluation. The Philadelphia, Boston, IBI Score, and American Academy of Pediatrics Clinical Practice Guideline did not misclassify any SBI or IBI as low risk; however, they had low specificity and positive predictive value. Rochester and Pediatric Emergency Care Applied Research Network tools misclassified infants with bacterial infections. CONCLUSIONS: Several febrile infant decision tools were highly sensitive, minimizing missed SBIs and IBIs in hypothermic infants. However, the low specificity of these decision tools may lead to unnecessary testing, antimicrobial exposure, and hospitalization.

Time to Positive Blood and Cerebrospinal Fluid Cultures in Hypothermic Young Infants.

BACKGROUND AND OBJECTIVE: Hypothermia in young infants may be secondary to an invasive bacterial infection. No studies have explored culture time-to-positivity (TTP) in hypothermic infants. Our objective was to compare TTP of blood and cerebrospinal fluid (CSF) cultures between pathogenic and contaminant bacteria in hypothermic infants ≤90 days of age. METHODS: Secondary analysis of a retrospective cohort of 9 children's hospitals. Infants ≤90 days of age presenting to the emergency department or inpatient setting with hypothermia from September 1, 2017, to May 5, 2021, with positive blood or CSF cultures were included. Differences in continuous variables between pathogenic and contaminant organism groups were tested using a 2-sample t test and 95% confidence intervals for the mean differences reported. RESULTS: Seventy-seven infants met inclusion criteria. Seventy-one blood cultures were positive, with 20 (28.2%) treated as pathogenic organisms. Five (50%) of 10 positive CSF cultures were treated as pathogenic. The median (interquartile range [IQR]) TTP for pathogenic blood cultures was 16.8 (IQR 12.7-19.2) hours compared with 26.11 (IQR 20.5-48.1) hours for contaminant organisms (P < .001). The median TTP for pathogenic organisms on CSF cultures was 34.3 (IQR 2.0-53.7) hours, compared with 58.1 (IQR 52-72) hours for contaminant CSF organisms (P < .186). CONCLUSIONS: Our study is the first to compare the TTP of blood and CSF cultures between pathogenic and contaminant bacteria in hypothermic infants. All pathogenic bacteria in the blood grew within 36 hours. No difference in TTP of CSF cultures between pathogenic and contaminant bacteria was detected.

Prevalence of Invasive Bacterial Infection in Hypothermic Young Infants: A Multisite Study.

OBJECTIVE: To determine the prevalence of bacteremia and meningitis (invasive bacterial infection [IBI]) in hypothermic young infants, and also to determine the prevalence of serious bacterial infections (SBI) and neonatal herpes simplex virus and to identify characteristics associated with IBI. STUDY DESIGN: We conducted a retrospective cohort study of infants ≤90 days of age who presented to 1 of 9 hospitals with historical or documented hypothermia (temperature ≤36.0°C) from September 1, 2017, to May 5, 2021. Infants were identified by billing codes or electronic medical record search of hypothermic temperatures. All charts were manually reviewed. Infants with hypothermia during birth hospitalization, and febrile infants were excluded. IBI was defined as positive blood culture and/or cerebrospinal fluid culture treated as a pathogenic organism, whereas SBI also included urinary tract infection. We used multivariable mixed-effects logistic regression to identify associations between exposure variables and IBI. RESULTS: Overall, 1098 young infants met the inclusion criteria. IBI prevalence was 2.1% (95% CI, 1.3-2.9) (bacteremia 1.8%; bacterial meningitis 0.5%). SBI prevalence was 4.4% (95% CI, 3.2-5.6), and neonatal herpes simplex virus prevalence was 1.3% (95% CI, 0.6-1.9). Significant associations were found between IBI and repeated temperature instability (OR, 4.9; 95% CI, 1.3-18.1), white blood cell count abnormalities (OR, 4.8; 95% CI, 1.8-13.1), and thrombocytopenia (OR, 5.0; 95% CI, 1.4-17.0). CONCLUSIONS: IBI prevalence in hypothermic young infants is 2.1%. Further understanding of characteristics associated with IBI can guide the development decision tools for management of hypothermic young infants.

Diagnostic testing for evaluation of brief resolved unexplained events.

BACKGROUND: Since the publication of the American Academy of Pediatrics (AAP) clinical practice guideline for brief resolved unexplained events (BRUEs), a few small, single-center studies have suggested low yield of diagnostic testing in infants presenting with such an event. We conducted this large retrospective multicenter study to determine the role of diagnostic testing in leading to a confirmatory diagnosis in BRUE patients. METHODS: Secondary analysis from a large multicenter cohort derived from 15 hospitals participating in the BRUE Quality Improvement and Research Collaborative. The study subjects were infants < 1 year of age presenting with a BRUE to the emergency departments (EDs) of these hospitals between October 1, 2015, and September 30, 2018. Potential BRUE cases were identified using a validated algorithm that relies on administrative data. Chart review was conducted to confirm study inclusion/exclusion, AAP risk criteria, final diagnosis, and contribution of test results. Findings were stratified by ED or hospital discharge and AAP risk criteria. For each patient, we identified whether any diagnostic test contributed to the final diagnosis. We distinguished true (contributory) results from false-positive results. RESULTS: Of 2036 patients meeting study criteria, 63.2% were hospitalized, 87.1% qualified as AAP higher risk, and 45.3% received an explanatory diagnosis. Overall, a laboratory test, imaging, or an ancillary test supported the final diagnosis in 3.2% (65/2036, 95% confidence interval [CI] 2.7%-4.4%) of patients. Out of 5163 diagnostic tests overall, 1.1% (33/2897, 95% CI 0.8%-1.5%) laboratory tests and 1.5% (33/2266, 95% CI 1.0%-1.9%) of imaging and ancillary studies contributed to a diagnosis. Although 861 electrocardiograms were performed, no new cardiac diagnoses were identified during the index visit. CONCLUSIONS: Diagnostic testing to explain BRUE including for those with AAP higher risk criteria is low yield and rarely contributes to an explanation. Future research is needed to evaluate the role of testing in more specific, at-risk populations.

Risk Prediction After a Brief Resolved Unexplained Event.

OBJECTIVES: Only 4% of brief resolved unexplained events (BRUE) are caused by a serious underlying illness. The American Academy of Pediatrics (AAP) guidelines do not distinguish patients who would benefit from further investigation and hospitalization. We aimed to derive and validate a clinical decision rule for predicting the risk of a serious underlying diagnosis or event recurrence. METHODS: We retrospectively identified infants presenting with a BRUE to 15 children's hospitals (2015-2020). We used logistic regression in a split-sample to derive and validate a risk prediction model. RESULTS: Of 3283 eligible patients, 565 (17.2%) had a serious underlying diagnosis (n = 150) or a recurrent event (n = 469). The AAP's higher-risk criteria were met in 91.5% (n = 3005) and predicted a serious diagnosis with 95.3% sensitivity, 8.6% specificity, and an area under the curve of 0.52 (95% confidence interval [CI]: 0.47-0.57). A derived model based on age, previous events, and abnormal medical history demonstrated an area under the curve of 0.64 (95%CI: 0.59-0.70). In contrast to the AAP criteria, patients >60 days were more likely to have a serious underlying diagnosis (odds ratio:1.43, 95%CI: 1.03-1.98, P = .03). CONCLUSIONS: Most infants presenting with a BRUE do not have a serious underlying pathology requiring prompt diagnosis. We derived 2 models to predict the risk of a serious diagnosis and event recurrence. A decision support tool based on this model may aid clinicians and caregivers in the discussion on the benefit of diagnostic testing and hospitalization (https://www.mdcalc.com/calc/10400/brief-resolved-unexplained-events-2.0-brue-2.0-criteria-infants).

Neonatal Use of Acute Care Services During the COVID-19 Pandemic.

OBJECTIVE: To describe changes in neonatal use of acute care services during the coronavirus disease 2019 (COVID-19) pandemic. We hypothesized neonatal visits would decrease and the degree of decline would vary by condition. METHODS: We conducted a retrospective cohort study of neonatal visits to the urgent cares, emergency departments, inpatient units, and intensive care units at a free-standing pediatric healthcare system during the COVID-19 pandemic and a comparator period. We included visits of infants presenting for acute care within the first 30 days of life. Transfers from a referring nursery, inpatient unit, or ICU were excluded. Data collected included demographics, patient characteristics, and visit characteristics. Descriptive statistics and χ2 tests were used for analyses and to determine statistically significant differences. RESULTS: We identified 4439 neonatal acute care visits, of which 2677 occurred in the prepandemic period and 1762 in the COVID-19 pandemic period, representing a 34.2% decline. Urgent cares and emergency departments experienced the greatest decline in visits for infectious conditions (49%) and the proportion of these visits also significantly decreased. Similarly, the largest clinically significant declines in hospitalizations were for infectious and respiratory diagnoses (48% and 52%, respectively) and the proportions of these hospitalizations also significantly decreased. Despite a small decline in hospitalizations for jaundice, the proportion of jaundice hospitalizations significantly increased by 5.7% (P = .02). CONCLUSIONS: The COVID-19 pandemic was associated with a significant reduction in neonatal visits across a spectrum of acute care settings. The impact on use varied by diagnosis with the most notable decline in visits for infectious conditions.