Heart rate to identify non-febrile children with dehydration and acute kidney injury in emergency department: a prospective validation study.

We previously developed and retrospectively validated the estimated percentage of heart rate variation (EHRV) as a predictor of the composite outcome of ≥ 5% dehydration and/or acute kidney injury (AKI) in non-febrile children. The current study aimed to prospectively validate EHRV as a predictor for dehydration or AKI in a different cohort of children attending the Pediatric Emergency Department. From July 2022 to August 2023, 256 pediatric patients aged 0-18 years attending the Pediatric Emergency Department were enrolled. EHRV was calculated as follows: [(HR at admission - 50th percentile of HR for age and sex)/HR at admission] × 100. Dehydration was categorized as < 5% or ≥ 5% fluid deficit. AKI was defined according to KDIGO creatinine criteria. Statistical analyses included receiver-operating characteristic (ROC) curves and logistic regression analysis. Among enrolled patients, 52 had ≥ 5% dehydration, 50 had AKI, and 16 had both conditions. EHRV demonstrated significant predictive ability for both ≥ 5% dehydration (AUROC = 0.71; 95% confidence interval (CI), 0.63-0.78; p < 0.001) and AKI (AUROC = 0.78; 95% CI, 0.71-0.84; p < 0.001). An EHRV > 24.5% was associated with an increased odds ratio (OR), adjusted for confounders, of ≥ 5% dehydration (OR = 3.5; 95% CI, 1.6-8.0; p = 0.003) and AKI (OR = 3.4; 95% CI, 1.6-7.3; p = 0.002). The sensitivity and specificity of this cut-off were 34% and 83% for ≥ 5% dehydration and 36% and 84% for AKI, respectively.

conclusionsThis study prospectively validates the clinical utility of EHRV in predicting dehydration and AKI in a pediatric emergency care setting. An EHRV > 24.5% could serve as a marker for suspecting dehydration or AKI. Further validation across diverse patient populations and settings is needed. WHAT IS KNOWN: • An increased heart rate (HR) is a readily detectable sign of dehydration in children. • In a retrospective validation cohort, an estimated HR variation (EHRV) greater than 24.5% compared to the 50th percentile of HR was predictive of ≥ 5% dehydration and/or acute kidney injury (AKI) in non-febrile patients. WHAT IS NEW: • We prospectively validated the clinical utility of EHRV in predicting dehydration and AKI in a pediatric emergency care setting. • We confirmed that an EHRV greater than 24.5% is associated with increased odds of ≥ 5% dehydration and AKI.