Propofol sedation in severe head injury fails to control high ICP, but reduces brain metabolism.

We have compared the effects of an intravenous infusion of propofol with those of morphine and midazolam on global brain metabolism (AVDO2) and brain perfusion following severe head injury. Fifteen patients were sedated with either a continuous infusion of propofol (mean rate 232 mg/h, range 150-400 mg/h) or infusions of morphine (mean rate 2.3 mg/h, range 0-4 mg/h) and midazolam (mean rate 2.8 mg/h, range 0-5 mg/h). Both groups were well matched for sex, age and level of coma (Glasgow coma scale) prior to sedation. Continuous data collection of AVDO2, mean arterial blood pressure (MABP), intracranial pressure (ICP), and cerebral perfusion pressure (CPP) began at 12 hours post injury and continued for a mean period of 40 hours. Morphine and midazolam did not have a significant effect on any of the measured parameters. Propofol led to a fall in AVDO2 from 6.0 +/- 2.6 ml/dl to 3.0 +/- 0.6 ml/dl at 4 hours. However, there was no effect on MABP, ICP or CPP. Outcome was similar in the 2 groups.