Anterograde and retrograde memory in children anesthetized with propofol

Prior to anesthesia with propofol for gastrointestinal endoscopy, sets of pictures were presented to 20 children and adolescents (M age = 12 years). Word pairs (e.g., "hiking-woods") were presented via earphones after the children were anesthetized. Upon regaining consciousness, the children were tested for explicit memory of both the picture sets and word pairs by free recall, cued recall, and yes/no recognition. Implicit memory was tested by free association to category cues for the pictures and by word association for the word pairs. Postoperative testing revealed retrograde memory for material presented preoperatively but total amnesia for material presented intraoperatively. There was no evidence of implicit memory for material not available explicitly. The finding of uninterrupted ability to retain and retrieve information presented prior to anesthesia despite total anterograde amnesia has implications for preoperative communication directed toward pediatric patients as well as for intraoperative communication among surgical staff.