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. Conclusions: This 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. (Table presented.).