†=P < 0.05 between I and II and between II and III.
‡=P < 0.05 compared with group I.
§=P < 0.05 between tpeakand tMinMAP.
∥=P < 0.05 between II and III.
tpeak= observed time necessary for reaching maximal drug effect (lowest BIS), taken within 2 min of the loss of consciousness ; teq= calculated time necessary for equilibration between CpCALC(the plasma propofol concentration) and CeCALC(the effect-site propofol concentration). This was not calculated for group I, in which CeCALCshould only approach CpCALCasymptotically, and therefore teqis infinite ; terror= teq− tpeak; CpMAX= calculated maximum plasma propofol concentration ; BISpeak= observed BIS at tpeak; tMinMAP= observed time to lowest arterial blood pressure (the “onset of side-effect”).