Upon arrival, post-operatively, to the Neurosciences Intensive Care Unit, the patient will have randomization completed via online randomization program. Randomization will be to allocate patients to either of two groups: 1) Ketamine first or 2) Propofol/other first. No secondary randomization criteria are thought to be necessary given the small sample size for this pilot trial. Initiation of the protocoled sedation regimen will begin on the next hour divisible by 6 (i.e. 06:00, 12:00, 18:00, 24:00). The randomization will determine which sedative to start, and after that the ketamine and propofol/other infusions will be alternated every 6 hours on the above schedules.