Pressure reactivity index for early neuroprognostication in poor-grade subarachnoid hemorrhage

• Published in: Journal of the neurological sciences 2023-07, Vol.450, p.120691-120691, Article 120691
• Main Authors: Chang, Jason J., Kepplinger, David, Metter, E. Jeffrey, Felbaum, Daniel R., Mai, Jeffrey C., Armonda, Rocco A., Aulisi, Edward F.
• Format: Article
• Language: English
• Subjects: Cerebral autoregulation; Pressure reactivity index; Prognostication; PRx; Subarachnoid hemorrhage
• ISSN: 0022-510X; 1878-5883
• DOI: 10.1016/j.jns.2023.120691

Pressure reactivity index (PRx) utilizes moving correlation coefficients from intracranial pressure (ICP) and mean arterial pressures to evaluate cerebral autoregulation. We evaluated patients with poor-grade subarachnoid hemorrhage (SAH), identified their PRx trajectories over time, and identified threshold time points where PRx could be used for neuroprognostication. Patients with poor-grade SAH were identified and received continuous bolt ICP measurements. Dichotomized outcomes were based on ninety-day modified Rankin scores and disposition. Smoothed PRx trajectories for each patient were created to generate “candidate features” that looked at daily average PRx, cumulative first-order changes in PRx, and cumulative second-order changes in PRx. “Candidate features” were then used to perform penalized logistic regression analysis using poor outcome as the dependent variable. Penalized logistic regression models that maximized specificity for poor outcome were generated over several time periods and evaluated how sensitivities changed over time. 16 patients with poor-grade SAH were evaluated. Average PRx trajectories for the good (PRx  0.5) started diverging at post-ictus day 8. When targeting specificities ≥88% for poor outcome, sensitivities for poor outcome consistently increased to >70% starting at post-ictus days 12–14 with a maximum sensitivity of 75% occurring at day 18. Our results suggest that by using PRx trends, early neuroprognostication in patients with SAH and poor clinical exams may start becoming apparent at post-ictus day 8 and reach adequate sensitivities by post-ictus days 12–14. Further study is required to validate this in larger poor-grade SAH populations. •Early prognostication in poor-grade subarachnoid hemorrhage is difficult.•Pressure reactivity index monitoring may allow for early prognostication.•PRx for good and poor outcome in subarachnoid hemorrhage diverges at post-ictus day 8.•PRx for poor outcome reaches maximum sensitivity and specificity by post-ictus day 13.•PRx may be a dynamic variable that changes over time in subarachnoid hemorrhage.