Psychomotor performance after short-term anaesthesia

Background and objective: The aim was to examine the immediate effects of short-term anaesthesia on the different components of psychomotor performance of the upper extremity and cognitive functions, and to find out if there were any differences in the sensitivities of the different tests. The measured psychomotor aspects were simple reaction time, choice reaction time, speed of movement, index finger-tapping speed, co-ordination, visual spatial memory capacity, digit-symbol substitution and the Maddox Wing test. Methods: The subjects were 30 female patients aged 24–50 yr who had been through a minor gynaecological operation. Anaesthesia had been induced with propofol and alfentanil. The measurements were mainly made with the HPM/BEP system, and the tests were performed 1 h before the anaesthesia and immediately after the wake-up. Results: Short-term anaesthesia prolonged the simple reaction time by 7% and the choice reaction times by 25% (one-choice) and 7% (two-choice) and decreased the speed of movement by 10% (one-choice) and 19% (two-choice), index finger-tapping speed by 7% and co-ordination by 7%. In addition, visual spatial memory capacity decreased by 21%, digit-symbol substitution increased by 5% and the Maddox Wing test increased by 68%. Conclusions: Based on the results, it seems that short-term anaesthesia reduces both signal processing at the central level, and motor control and co-ordination of movements at the peripheral level, and has a decreasing effect on motor performance in the above-mentioned aspects measured immediately after wake-up.