Cerebrospinal Fluid (CSF) Drainage Study

High Volume Cerebrospinal Fluid Diversion in the Management of Aneurysmal Subarachnoid Hemorrhage: A Pilot Study

When patients suffer a subarachnoid hemorrhage (bleeding around the brain), they often develop hydrocephalus. This is an enlargement of the fluid-filled spaces (ventricles) in the brain. Standard-of-care treatment includes placing an external ventricular drain (EVD) to drain off fluid. Eventually the EVD is weaned with the goal of removing it. Occasionally a patient does not tolerate this and a permanent surgery needs to be done to internalize a shunt. Though this is done commonly and routinely throughout the world, there are no good studies to address how to optimally set the EVD level and how fast to wean it. Most set the EVD to a level of around 15 mmHg. The investigators hypothesize that setting the EVD lower (which will allow higher volume Cerebrospinal Fluid (CSF) drainage through the EVD) will improve perfusion at the level of the microcirculation in the brain, and result in improved neurologic outcomes.

The EVD will be set to an initial level of 5 mmHg. The drain will remain in place at a level of ≤ 5 mmHg until at least day 10 after SAH before a weaning trial is attempted.

The EVD will be set to a level of 15 mmHg for as long as needed for the treatment of hydrocephalus, and subsequently weaned at the discretion of the treating physician. Lowering the level of the EVD can be considered by the treating physician if sustained intracranial hypertension occurs

The primary outcome is clinical outcome at 90 days. A favorable outcome is defined as a score of 1 or 2 on the modified Rankin Score (mRS) and poor outcome defined as a mRS of 3-6. This assessment will be made by a clinician who was blinded to the patient's CSF diversion treatment arm.

Inclusion Criteria Age ≥ 18 years Diagnosis of acute subarachnoid hemorrhage (SAH), confirmed with noncontrast head CT SAH is suspected to be aneurysmal in source Clinical management requires placement of EVD within 2 days of suspected time of hemorrhage Exclusion Criteria Age < 18 years SAH of traumatic or non-aneurysmal etiology Patients treated with lumbar drains EVD placement ≥ 3 days after suspected time of hemorrhage Known contraindication to induction of relative intracranial hypotension (e.g. acute subdural hematoma) Pre-morbid mRS ≥ 3 EVD that is suboptimally placed by CT obtained after EVD placement (i.e. EVD not in the ventricular system)