Prolonged Mild-to-Moderate Hypothermia for Refractory Intracranial Hypertension.

BACKGROUND: Therapeutic hypothermia is an emerging therapy for brain injury and cerebral edema. Hypothermia is known to reduce death and neurologic morbidity in survivors of cardiac arrest from ventricular fibrillation. Traumatic brain injury (TBI) trials studies of short-term hypothermia (24 to 48hours) have had conflicting results. Recent evidence however suggests prolonged hypothermia (48 hours to 14 days) may be beneficial for TBI and select cases of nontraumatic brain injury especially when the duration of cerebral edema and intracranial hypertension is expected to last longer than 24 hours. CASE REPORT: A 43-year-old female presented with a Fisher grade 4 aneurysmal (anterior communicating artery) subarachnoid hemorrhage. The patient was comatose upon transfer to our hospital, was intubated, and had immediate aneurysm coiling. The patient had a right external ventricular drain (EVD) placed for acute hydrocephalus and intracranial pressure (ICP) monitoring. The patient developed severe vasospasm of several intracranial vessels requiring angioplasty on two consecutive days, and hypertensive, hypervolemic, hemodilution therapy (HHH). On the ninth day, ICP went above 20mmHg and computed tomography (CT) showed global cerebral edema. For the next 17 days, the patient had refractory intracranial hypertension, requiring sedation, neuromuscular blockade, hyperosmolar therapy (3% infusion, and 23.4% saline boluses), thiopental coma with burst suppression, and hypothermia (31 to 34C). Hypothermia continued for a total of 14 days before ICP and edema on CT normalized.
CONCLUSION: We report the first case of prolonged therapeutic hypothermia over a total of 14days to control nontraumatic brain injury-related refractory intracranial pressure and global cerebral edema. More studies are needed comparing clinical outcomes and complication rates between short duration and prolonged hypothermia for brain injury.