RECALL DURING INTERMITTENT PROPOFOL ANESTHESIA

We discontinued temporarily an infusion of propofol for surgical reaso ns in 20 patients undergoing incontinence surgery. The patients, who h ad not received neuromuscular blockers, were allowed to regain conscio usness to a level enabling them to cough on command, open their eyes, and identify and verbally confirm a randomly assigned digit shown on p aper. Thereafter, 5-14 min after discontinuation of the propofol infus ion, anaesthesia was reinstituted. Memory of the request to cough, a s tandard conversation and the digit shown was tested 1 h after anaesthe sia and on the following day. Only 35% of patients were able to recall one or more of the stimuli presented during wakefulness or were even able to recall having been ''awake'', and there were very few differen ces in memory on the day after surgery compared with 1 h after anaesth esia. In comparison with corresponding stimuli given before anaesthesi a, memory of material learned during wakefulness was significantly imp aired (P < 0.0001). Thus patients temporarily capable of cognitive act ion during propofol anaesthesia may have no subsequent explicit recall of intraoperative events.