High-Resolution Intracranial Pressure Burden and Outcome in Subarachnoid Hemorrhage

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 (PTDICP) is a method to quantify the burden and the time spent above a defined threshold of ICP. PTDICP 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. PTDICP (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 PTDICP15, PTDICP20, PTDICP25, PTDICP30 were, respectively, 13, 4, 2, and 1 mm Hg h. We observed an association between mortality at hospital discharge and higher level of PTDICP using 20, 25, and 30 mm Hg as thresholds and between exposure to a moderate-level PTDICP30 and unfavorable long-term outcome. Conclusions - PTDICP may better define one of the insults that the brain suffers after aneurysmal rupture, and exposure to moderate PTDICP30 was significant prognostic factor of 6-month unfavorable outcome.