Abstract T P316: Occurrence of Intracranial Hypertension in the First 400 Patients Enrolled in the Clot Lysis: Evaluation of Accelerated Resolution of Intraventricular Hemorrhage Trial (CLEAR III)

Abstract

Background: Elevated intracranial pressure (ICP) is one proposed mechanism leading to poor outcomes in patients with spontaneous intraventricular hemorrhage (IVH). We characterized occurrence and significance of intracranial hypertension in severe IVH requiring extraventricular drainage (EVD). Methods: Prospective analysis of ICP in the first 400 patients enrolled in the CLEAR III trial, a multicenter, double-blind, randomized study comparing EVD plus intraventricular recombinant tissue plasminogen activator (rtPA) vs. EVD plus placebo for treatment of IVH in patients with obstructive IVH and intracerebral hemorrhage (ICH) volume <30cc. Maximum and minimum ICP was recorded every 4 hours in all patients until 7 days post randomization. ICP readings were analyzed at pre-defined thresholds and proportion of high ICP events compared by clinical/radiological variables. Impact on 30 day mortality was assessed. Results: of 17,593 ICP readings, maximum ICP ranged from -4 to 115 mm Hg (median, interquartile range; 11,8); 90.2% (15,861) were ≤ 20 mm Hg, 2.0% were >30, 0.5% were >40, and 0.2% were > 50 mm Hg. Proportion of threshold events > 20 and > 30 mm Hg were more frequent in patients with persistent closure of the lower ventricular system after day 3 (p=0.047 and p=0.04, respectively), but were not correlated with initial or end of treatment (72 hours after last dose of study agent) ICH or IVH volumes. ICP elevation > 20 mm Hg occurred during a required 1 hr EVD closure time after study agent injection in 507/3364 (15.1%) injections although early re-opening of EVDs occurred in only 3.9%. Shunting for hydrocephalus was required in 18% of patients over 1 yr follow-up and was not associated with high ICP events. Percentage of ICP readings per patient > 30 mmHg and ICH/IVH volumes were independent predictors of 30 day mortality after adjustment for other outcome predictors (p=0.01; p=0.04; p<0.001, respectively). Conclusions: ICP is not frequently elevated during monitoring and drainage with an EVD in patients with severe IVH. ICP > 30 mm Hg predicts higher short-term mortality. Early opening of the lower ventricular system may reduce frequency of high ICP events. Injection of thrombolytics can be performed without additional ICP management in the majority of patients.