Ketamine Infusion in Neurologic Deficit

Subarachnoid hemorrhage (SAH) or bleeding in the brain as a result of ruptured aneurysm is a devastating type of stroke. Many patients who undergo emergent neurosurgery to repair the aneurysm and remove the bleeding suffer from complications in their subsequent hospital stay, the most frequent and morbid of which is delayed cerebral ischemia (DCI) or small strokes resulting from impaired blood flow to certain vital brain centers. This occurs because of changes to the brain's blood vessels that occur after the bleed. The arteries can become narrow (spasm) or small clots can form within the vasculature that disrupts normal blood flow. Patients are left with profound neurologic deficits from these secondary complications. Anesthesiologists, neurosurgeons, and intensivists are in need of a way to protect the brain during this vulnerable period following aneurysm repair. One drug that may provide such protection is ketamine, a compound frequently used in operating rooms and intensive care units to provide anesthesia and analgesia. Ketamine works by blocking glutamate receptor ion channels that play a pivotal role in promoting brain cell death during strokes by flooding the brain with too much calcium and dangerous chemicals. This project is designed to test the efficacy of ketamine in protecting the brain following aneurysm repair by using a controlled infusion of the drug in the intensive care unit (ICU) when patients return from their operation.