Incidence of memory of transoperative events during total intravenous general anesthesia with propofol

The incidence of memories of events during the total intravenous general anesthesia is studied in a 400 adult patient group in order to establish the influence of the included doses of drugs in this scheme, upon the mentioned incidence. The anesthetic method included propofol, fentanyl and vecuronium. Two groups of patients were constituted according to the propofol infusion rate (PIR) required for the anesthetic maintenance: group I required a PIR < 6.0 mg.kg-1.h-1, and group II required a PIR > 6.0 mg.kg-1.h-1. Transanesthetic monitoring was done with cardiac frequency, systolic and diastolic arterial pressures, ECG, pulse oximeter oxygen saturation and end tidal CO2. The memory incidence of transoperative events was obtained through postoperative interviews about intraoperative events. Patients in group I had a significantly greater remembrance incidence both in real events and in dreams than the patients in group II. We conclude that a PIR of propofol < 6.0 mg.kg-1.h-1 can be associated with a high incidence of remembrances of transoperative events.