Effects of small concentrations of isoflurane on some psychometric measurements.
We have investigated the effects of 9.5% and 14.1% MAC concentrations of isoflurane on some psychometric measurements. Both concentrations depressed peak saccadic velocity (P < 0.01), choice reaction time (P < 0.05) and visual analogue scores for sedation (P < 0.05), but not the critical flicker fusion threshold. The incidence of errors in saccade tasks increased in a dose-related fashion, which made analysis of peak saccadic velocity less accurate at more than 10% MAC. The percentage error itself was an indicator of the depth of sedation. All the objective measures correlated highly with the estimated brain tension of isoflurane (r2 = 0.86-0.96), but not the visual analogue score for sedation (r2 = 0.51). This suggests that a combination of peak saccadic velocity, percentage error and choice reaction time is a potentially useful batch of tests to measure recovery from anaesthesia.
Yoshizumi
J
J
Department of Anaesthetics, University of Wales College of Medicine, Health Park, Cardiff.
Marshall
R W
RW
Sanders
L D
LD
Vickers
M D
MD
D000328:Adult; D000769:Anesthesia, Inhalation; D004305:Dose-Response Relationship, Drug; D005260:Female; D005425:Flicker Fusion / Q000187:drug effects* / Q000502:physiology; D006801:Humans; D007530:Isoflurane / Q000008:administration & dosage / Q000494:pharmacology*; D008297:Male; D011594:Psychometrics; D011930:Reaction Time / Q000187:drug effects*; D012438:Saccades / Q000187:drug effects*; D012684:Sensory Thresholds / Q000187:drug effects
D007530:Isoflurane