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Abstract: FR-PO1136

Systolic Blood Pressure Z-Score Accurately Predicts Development of Posterior Reversible Encephalopathy Syndrome in Children

Session Information

  • Pediatric Nephrology - I
    October 26, 2018 | Location: Exhibit Hall, San Diego Convention Center
    Abstract Time: 10:00 AM - 12:00 PM

Category: Pediatric Nephrology

  • 1600 Pediatric Nephrology

Authors

  • Gall, Emily K., Wake Forest School of Medicine, Winston-Salem, North Carolina, United States
  • South, Andrew M., Wake Forest School of Medicine, Winston-Salem, North Carolina, United States
Background

While posterior reversible encephalopathy syndrome (PRES) is often reversible, it increases morbidity and mortality in children and adults. High blood pressure (BP) is a major risk factor for PRES and is thought to alter cerebral vascular autoregulation leading to vasogenic edema. However, little is known about what severity of high BP predicts PRES, especially in children, as most patients with high BP do not develop PRES. The purpose of this study is to determine a clinically meaningful BP threshold above which the risk of developing PRES is increased.

Methods

We recorded the maximum systolic BP and diastolic BP and BP z-scores in the 14 days preceding development of PRES in a case-control study of 35 children with PRES compared to 14 controls matched on similar risk factors (underlying disease, renal function, and medications) and who had clinical concern for PRES but had normal brain magnetic resonance imaging. We used logistic regression models to determine the effect of maximum BP on the risk of developing PRES, reported as odds ratios with 95% CI. We then constructed receiver operator characteristic (ROC) curves for different maximum-BP cut points to determine their prognostic ability to predict PRES and calculated sensitivity, specificity, and positive and negative predictive values.

Results

Cases had a higher rate of baseline hypertension (97.1% vs 64.3%, p=0.005) but were otherwise well matched. 14-day maximum SBP z-score was strongly associated with PRES (OR 4.0, 95% CI 1.6 to 9.6). ROC analysis revealed that 14-day maximum SBP z-score ≥3.0 accurately predicted PRES (AUC 0.95, 95% CI 0.88 to 1.0) with 91.2% sensitivity (95% CI 81.4 to 100%) and 84.6% specificity (65.2 to 100%), indicating a positive predictive value of 93.9% (84.3 to 100%) and a negative predictive value of 78.6% (56.9 to 100%).

Conclusion

Our study demonstrated that a maximum SBP z-score of 3.0 or higher in the preceding 14 days accurately predicted PRES development in pediatric cases as compared to controls with similar risk factors. This indicates that the SBP 99th percentile for age, sex, and height (equivalent to a z-score of 3.0) may be a clinically relevant threshold indicating that aggressive BP reduction is warranted in children at high risk for PRES in order to prevent target organ damage in the brain.