S-ketamine versus placebo for cortical spreading depolarisation in severe acute brain injury (KETA-BID): protocol for a pilot, randomised, blinded clinical trial.

INTRODUCTION

Cortical spreading depolarisation (SD) is a pathological wave of depolarisation in the cortex. SDs occur frequently after severe acute brain injury, and SDs in clusters can contribute to secondary brain damage in patients with severe acute brain injury through hypoperfusion and upregulation of cerebral metabolism in vulnerable brain tissue. Ketamine appears to inhibit SDs both in vitro and in patient series of severe acute brain injury. The KETA-BID trial aims to examine the efficacy and safety of S-ketamine for SDs in severe acute brain injury, as well as the feasibility of the trial design.

METHODS AND ANALYSIS

This randomised, blinded feasibility and pilot trial includes adults (≥ 18 years) undergoing a supratentorial craniotomy or craniectomy for severe acute brain injury (ie, traumatic brain injury, aneurysmal subarachnoid haemorrhage or spontaneous intracerebral haemorrhage). During surgery, an electrocorticography (ECoG) strip is placed adjacent to injured brain tissue. Patients are continuously monitored throughout their stay at the neurointensive care unit and the neurosurgical step-down unit. In the case of an SD, physiological optimisation of intracranial pressure, brain tissue oxygen tension (PbtO), core temperature and blood glucose is initiated. Participants developing SD clusters are randomised for continuous infusion with S-ketamine or matching placebo in a 1:1 allocation with full blinding of the treatment allocation. Infusion rates (ie, dose) and duration of trial medication are adjusted following a dosing algorithm according to SD occurrence. Surviving participants are followed until 6 months after the injury with recording of functional outcome. The primary outcome is occurrence of SDs per hour of monitoring after randomisation.

ETHICS AND DISSEMINATION

The Scientific Ethics Committee of the Capital Region of Denmark (H-21056972), the Danish Medicines Agency (EudraCT 2021-003716-12), as well as the Clinical Trials Information System (CTIS 2024-515315-22-00) approved this trial. This trial will provide insight into both SD and the clinical effects of ketamine following severe acute brain injury, presenting a potential new treatment for these patients. The findings will be submitted for publication in peer-reviewed publications.

TRIAL REGISTRATION NUMBER

NCT05095857.