In order to determine the speed of onset of the anaesthetic propofol in children,
investigators will compare the two age groups 1-6 years vs 8-13 years. The primary outcome
measure is the time to peak effect of a bolus of proposal, which is measured by analysing the
electroencephalogram by using the permutation entropy. Further pharmacodynamic modelling will
enable investigators to quantify the difference with age in the hypnotic effect of propofol.