Assessment of the recovery of dynamic balance after intravenous sedation with midazolam.
OBJECTIVE
To assess street fitness after sedation, computerized dynamic posturography (CDP) involving movement of the center of gravity may be more accurate than the conventional computerized static posturography (CSP). The purpose of this study was to evaluate the recovery of dynamic balance function after intravenous sedation by CDP in comparison with CSP, and to find a simple dynamic balance test that is well correlated with CDP.


METHODS
The subjects were 20 male volunteers aged 20-27 years. After intravenous injection of midazolam (0.07 mg . kg(-1)), four balance tests were performed. The recovery time and the percentage of subjects showing recovery (difference from the baseline value < or =10%) were compared. As CDP, a test in which unexpected perturbation stimuli are given using an unstable platform was performed. As CSP, standing sway tests were performed. Maximum speed walking (MSW) and usual speed walking (USW) tests were performed as simple balance tests.


RESULTS
The recovery time in CDP (80 min) was longer than that in CSP (40-60 min). The percentage of subjects showing recovery in CDP (20%) was significantly lower than that in CSP (55%-70%) 60 min after the administration of midazolam. There was a significant positive correlation between the CDP test and the MSW test (r = 0.67).


CONCLUSIONS
CDP with perturbation stimuli detects the balance inhibitory effects of midazolam with greater sensitivity than CSP. The MSW test is well correlated with CDP with perturbation stimuli.
Fujisawa
Toshiaki
T
Department of Dental Anesthesiology, Graduate School of Dental Medicine, Hokkaido University, Kita-13 Nishi-7, Kita-ku, Sapporo, 060-8586, Japan.
Takuma
Shigeru
S
Koseki
Hiroyo
H
Kimura
Kunie
K
Fukushima
Kazuaki
K
D000328:Adult; D016292:Procedural Sedation; D006801:Humans; D006993:Hypnotics and Sedatives / Q000008:administration & dosage / Q000494:pharmacology*; D007275:Injections, Intravenous; D008297:Male; D008874:Midazolam / Q000008:administration & dosage / Q000494:pharmacology*; D004856:Postural Balance / Q000187:drug effects*; D016138:Walking
D006993:Hypnotics and Sedatives; D008874:Midazolam