Exploring the Association of Systolic Blood Pressure and Intracranial Pressure Variability and Subarachnoid Hemorrhage Patient Outcomes

BackgroundSubarachnoid hemorrhage (SAH) results from extravasation of blood into the subarachnoid space and is associated with high morbidity and mortality. This study aimed to compare systolic blood pressure variability (SBPV) and intracranial pressure variability (ICPV) in three 8-hour intervals during the first 24 hours after hospital admission and investigate their associations with discharge disposition and in-hospital mortality. MethodsWe retrospectively reviewed charts of adult patients with spontaneous, non-traumatic SAH admitted for at least 24 hours from 2016-2020. Hourly measurements were recorded for both systolic blood pressure (SBP) and intracranial pressure (ICP), and SBPV and ICPV were measured using successive variation (SV) and standard deviation (SD). ResultsA total of 240 patients were included (mean age 57{+/-}14.2 years, 64.6% female); 40 (16.7%) died. In the first 8-hour interval, higher SBP-SV (22.7{+/-}13.8) was significantly associated with mortality (p=0.028) and not being discharged home (p=0.022), compared to those who survived (17.6{+/-}7.5) or were discharged home (16.7{+/-}5.5). No significant differences in ICPV emerged for mortality or disposition, though higher ICP-SV in the first 8 hours approached significance (p=0.054) for discharge disposition. Receiver operating curve analysis showed poor discrimination for the first 8-hour SBP-SV (area under the curve 0.62) and failure for ICP-SV (0.51) in predicting mortality. ConclusionsGreater SBP variability in the first 8 hours was linked to poorer outcomes, underscoring the potential importance of stabilizing blood pressure in this critical window. No clear association was observed between ICP variability and outcomes.