Computerized 4-choice reaction time test for the measurement of psychomotor recovery after general anesthesia

The recovery of patients after general anesthesia is usually estimated by using clinical scores. Since there is a lack of objective methods for assessing psychomotor recovery, the aim of this study was to evaluate three psychological tests for this purpose. Patients, scheduled for ambulatory gynecological surgery, underwent 3 standard psychological tests before (T1), 15 min after the surgery (T2) and on discharge from the recovery room (T3). The tests used were Wechsler memory scale (test 1, working memory capacity), d2-test (test 2, concentration endurance) and computer-based 4-choice-reaction time (4CRT, test 3, reaction time) as well as Postanesthesia Discharge Scoring System (PADSS). The same test battery was used in healthy female volunteers, all test results were compared at the different time points. In 109 patients, working memory capacity and concentration (tests 1 and 2) decreased, the reaction time (test 3) was prolonged at T2 in comparison with T1 and T3 (P < 0.01). PADSS increased from 8 (T2) to 10 (T3) (medians, P < 0.001). Fifty-seven healthy volunteers demonstrated a practice effect in all 3 tests through the course of the study (P <0.01). 4CRT test had shortest duration and enabled computerized data processing. All three tests objectively assess the recovery of psychomotor function in patients after general anesthesia, the computer-based 4CRT seems to be the most convenient for the clinical routine.