EVALUATION OF COGNITIVE FUNCTIONS FOLLOWI NG PROPOFOL ANESTHESIA

Objectives: To assess the disturbances and delay of recovery of cognit ive functions following propofol anaesthesia, and to evaluate a series or simple cognitive recovery tests. Study design: Prospective compara tive non randomized clinical study. Patients: Two groups of non premed icated patients, of ASA physical class 1 and 2 were studied. The contr ol group (n = 11) included patients undergoing gastric fibroscopy unde r local anaesthesia. The propofol group (n = 22) consisted of patients scheduled for coloscopy under propofol anaesthesia. Methods: The gast ric fibroscopy was performed under local anaesthesia with lidocaine an d the coloscopy under general anaesthesia with propofol as the sole an aesthetic. Five cognitive tests, designed to assess short-term memory, delayed memory, the ability to plan complex tasks, attention, and lan guage comprehension were conducted the day before, and 1 hour, 3 hours and 6 hours after the endoscopy. Results: The cognitive functions rem ained significantly depressed for al least 3 hours after anaesthesia, and recovered fully about 6 hours after the cessation of propofol admi nistration. The capacity for planning was the most heavily affected. C onclusions: Complete recovery can be evaluated by simple cognitive tes ts, which showed that cognitive functions are impaired over a longer p eriod than psychomotor functions. Oral instructions may therefore not be fully understood by the patient within 3 hours after anaesthesia, e mphasizing the importance of written instructions and the essential ro le played by a well-informed accompanying person.