Randomized, multiple-crossover ICU study (n=10) evaluating whether continuous ketamine infusion (basal ~0.1 mg/min, titrated) suppresses cortical spreading depolarizations compared with other sedation regimens.
Hypothesis: NMDA antagonist ketamine suppresses cortical spreading depolarizations (CSD). This prospective randomized multiple crossover pilot compares ketamine versus other sedatives in 6-hour alternating blocks in patients with severe traumatic brain injury or aneurysmal subarachnoid haemorrhage undergoing craniotomy and invasive cortical monitoring.
Continuous subdural electrode (1x6 strip) recordings capture CSD occurrence while physiological data (vitals, arterial waveforms, labs, video EEG) are collected; ketamine given as continuous infusion (minimal basal 0.1 mg/min, titrated) and compared to standard sedatives with outcomes focused on CSD frequency and related physiological markers.
Randomized to receive ketamine as the first post-operative sedative, then cross-over every 6 hours to other sedation.
Basal minimal infusion 0.1 mg/min (≈6 mg/hr); titrated to Riker SAS target; single 6-hour blocks alternated.
Randomized to receive non-ketamine sedation (typically propofol) first, then cross-over every 6 hours to ketamine.
Other sedation (typically propofol, versed, or dexmedetomidine) titrated per ICU standard; no fixed minimal infusion required.
Ketamine used in alternating 6-hour blocks; basal minimal infusion 0.1 mg/min (≈6 mg/hr) during ketamine intervals.