Pilot Study of Ketamine Sedation for Aneurysmal Subarachnoid Hemorrhage — PENDULUM  

Subarachnoid Hemorrhage, Aneurysmal Clinical Trial

Official title: A Pilot Study of Ketamine Sedation Initiated Early After Aneurysmal Subarachnoid Hemorrhage: Effect on Vasospasm, Delayed Cerebral Ischemia, and Functional Outcomes

Status Withdrawn

Clinical Trial Summary

Aneurysmal subarachnoid hemorrhage (aSAH) is bleeding into the space between the brain and the tissues that surround the brain as a result of a ruptured aneurysm and is a type of stroke associated with high morbidity and mortality. Those that survive the initial bleed are critically ill and require prolonged intensive care unit stays since they are at risk for a multitude of secondary insults that can further worsen functional outcomes. An especially feared secondary insult is delayed cerebral ischemia (DCI), which is a lack of blood flow to a particular portion of the brain that can result in an ischemic stroke and produce profound neurologic deficits. How DCI develops in some people after aSAH and not others is unknown, but many have hypothesized various mechanisms such as 1) cerebral vasospasm, a focal anatomic narrowing of the blood vessels in the brain that could decrease downstream blood flow, 2) abnormal electrical activity, and 3) microthrombi, or the formation of small blood clots.

It is vitally important to identify a therapy that could protect the brain from these secondary insults that happen days after the initial brain bleed. Ketamine is a drug used in the majority of hospitals around the world for various indications, including general anesthesia, sedation, and for pain. Ketamine blocks a specific receptor that is present within the brain and in doing so could play a critical protective role against these secondary insults after aSAH by blocking the flow of dangerous chemicals. Ketamine may provide the following beneficial properties after aSAH: 1) pain control, 2) seizure prevention, 3) blood pressure support, 4) dilation of the brain blood vessels, 5) sedation, 6) anti-depressant, and 7) anti-inflammatory. This project is designed to test whether ketamine sedation in the intensive care unit after aneurysm repair provides better outcomes than the currently used sedation regimen.

Clinical Trial Description

Aneurysmal subarachnoid hemorrhage (aSAH) is a devastating form of hemorrhagic stroke associated with high morbidity and mortality, which has been linked to the development of cerebral vasospasm (CV) and delayed cerebral ischemia (DCI). Two prominent mechanisms by which CV and DCI have been proposed to occur include cortical spreading depolarizations (CSDs) and neuroinflammation. Ketamine is a NMDA receptor antagonist that is in widespread and common clinical use as a general anesthetic, sedative, analgesic and anti-depressant, among other indications. The investigators hypothesize that early initiation of ketamine sedation following aneurysm securement in lieu of the usual propofol-based sedation regimen will improve aSAH outcomes via a multifactorial mechanism. Many potential mechanisms exist by which ketamine could be beneficial following aSAH, including but not limited to: 1) direct cerebrovasodilation, 2) inhibiting the development of and terminating ongoing CSDs, 3) reducing neuronal hyperexcitability and glutamate-mediated excitotoxicity, 4) positively modulating a plethora of neuroinflammatory cascades, and 5) reduced vasopressor requirements owing to intrinsic sympathomimetic properties. This study is a prospective randomized single-blind pilot and feasibility study to begin investigating whether early ketamine administration after aSAH attenuates CV, DCI, DCI-associated infarctions, and improves functional outcomes. ;

Related Conditions & MeSH terms

• Hemorrhage
• Subarachnoid Hemorrhage
• Subarachnoid Hemorrhage, Aneurysmal

• NCT number: NCT05032118
• Study type: Interventional
• Source: Oregon Health and Science University
• Status: Withdrawn
• Phase: Phase 2/Phase 3
• Start date: April 27, 2023
• Completion date: April 27, 2023