High-Resolution Intracranial Pressure Burden and Outcome in Subarachnoid Hemorrhage

Abstract

Background and Purpose— Intracranial pressure (ICP) control is a therapeutic target in patients with aneurysmal subarachnoid hemorrhage, although only a limited number of studies assessed its course and effect on outcome. Pressure–time dose (PTD ICP ) is a method to quantify the burden and the time spent above a defined threshold of ICP. PTD ICP or its relationship with outcome has never been evaluated in aneurysmal subarachnoid hemorrhage. Methods— Analysis of data prospectively collected from aneurysmal subarachnoid hemorrhage patients admitted to Neurointensive Care Unit. Monitored data, including intraparenchymal ICP, were digitally recorded minute-by-minute in the first 7 days. PTD ICP (mm Hg h) was computed using 4 predefined thresholds (15, 20, 25, and 30 mm Hg). Outcome was assessed through Extended Glasgow Outcome Scale at hospital discharge and at 6 months. Results— Fifty-five patients were enrolled. Forty-two patients (76%) presented with a poor clinical grade. Overall, mortality was 17% at hospital discharge and 34% at 6 months. Half of patients required extensive therapy to control high ICP during day 1. Median ICP was 10 mm Hg (4–75), whereas median PTD ICP15 , PTD ICP20 , PTD ICP25 , PTD ICP30 were, respectively, 13, 4, 2, and 1 mm Hg h. We observed an association between mortality at hospital discharge and higher level of PTD ICP using 20, 25, and 30 mm Hg as thresholds and between exposure to a moderate-level PTD ICP30 and unfavorable long-term outcome. Conclusions— PTD ICP may better define one of the insults that the brain suffers after aneurysmal rupture, and exposure to moderate PTD ICP30 was significant prognostic factor of 6-month unfavorable outcome.