Assessment of power spectral edge for monitoring depth of anaesthesia using low methohexitone infusion.

The study describes an attempt to determine the minimal sleep infusion rate for the intravenous anaesthetic, methohexitone using EEG power spectral edge (PSE) as an index of anaesthetic depth. PSE was found to remain stable during a continuous infusion at declining rates, with decreasing plasma concentration. We were unable to define a sleep infusion rate using PSE as an index of anaesthetic depth. PSE was found to be unsuitable for monitoring anaesthetic depth.