49 - Hypertension, Blood Pressure Variability, and Risk of Acute Kidney Injury in Hospitalized Children

Poster Number: 49
Publication Number: 49.340

James T. Nugent, Yale School of Medicine, Guilford, CT, United States; Lama Ghazi, Yale School of Medicine, NEW HAVEN, CT, United States; Yu Yamamoto, Yale School of Medicine, New Haven, CT, United States; Christine Bakhoum, Yale University, New Haven, CT, United States; Francis P. Wilson, Yale School of Medicine, New Haven, CT, United States; Jason H. Greenberg, Yale School of Medicine, new haven, CT, United States

Background: Management of inpatient pediatric hypertension is focused on prevention of end organ complications including acute kidney injury (AKI). However, the association between hypertension and blood pressure variability (BPV) with AKI is unknown.

Objective: To estimate the prevalence of hypertension in hospitalized children using pediatric blood pressure (BP) norms and to assess the association between inpatient hypertension and BPV with AKI.

Design/Methods: We conducted a nested case-control study of children aged 1 to 17 years who had ≥2 serum creatinine measurements during admission at two hospitals in the Yale-New Haven Health System from 2014 to 2018. Cases were patients who developed AKI during admission, defined by Kidney Disease: Improving Global Outcomes serum creatinine criteria, and were selected at the time of incident AKI onset. Ten controls for every case were selected using incidence density sampling to ensure that controls were at risk for AKI when AKI occurred in matched cases. We evaluated various thresholds of inpatient hypertension using age-, sex-, and height-based percentiles from the 2017 American Academy of Pediatrics guideline and BPV as the exposures, measured in the 72 hours before AKI. In a sensitivity analysis, we used Cox proportional hazards models to assess the association between the time-varying exposures of hypertension and BPV and the outcome of AKI in the full cohort.

Results: A total of 268,054 BP measurements were recorded during 5430 hospitalizations, with a median of 22 readings (IQR: 11-48) per encounter. Among all BP readings, 19.0% were ≥99th percentile and 32.9% were ≥95th percentile (Fig 1). AKI occurred in 392 (7.2%) encounters at a median of 54.4 hours after admission (IQR: 20.5-127.1), with stage 2 or 3 AKI in 151 (2.8%) encounters. Compared to controls, cases had more comorbidities and were more often located in the intensive care unit. Hypertension was observed more frequently in cases than controls (Table). We observed a U-shaped relationship between mean BP during the 72 hours before case-control selection and AKI risk (Fig 2). After adjusting for confounders, hypertension was not associated with AKI. In contrast, most measures of BPV remained significantly associated with any AKI and stage 2 or 3 AKI in the multivariable models. The results were similar in the Cox model using time-varying definitions of hypertension and BPV for the full cohort.Conclusion(s): BPV was independently associated with AKI in hospitalized children and may be a modifiable risk factor for AKI.
CVNugent - CV - 1.3.22 - PAS.pdf
Table. Association Between Incident Acute Kidney Injury and Selected Definitions of Hypertension and Measures of Blood Pressure Variability in the Preceding 72 Hours