Assessment of Wakefulness by Measuring Eye Movements after Injection of Flumazenil during Intravenous Sedation with Midazolam

Abstract

Objectives: Over-sedation and lingering sedation have been reported as problems associated with intravenous sedation (IVS). Saccadic eye movements can be used as parameters for the objective and quantitative evaluation of sedative effects. Study design: Measurement of saccadic eye movements using a wearable Talk Eye Lite® (TEL) tracking device is useful for evaluating recovery following IVS. However, the assessment of awakening by measuring saccadic eye movements in subjects treated with flumazenil following midazolam sedation has not yet been reported. In the present study, the effect of flumazenil on eye movements was assessed during the recovery process. Results: A relatively long period of time was required for the recovery of saccadic eye movements even following the injection of physiological saline. Conversely, the recovery of saccadic eye movements occurred immediately following the injection of flumazenil. Saccadic eye movement parameters reflected the recovery from induced sedation with midazolam even in cases where flumazenil was utilized. The saccadic peak velocity was delayed again 50 min after the injection of flumazenil during IVS. Conclusion: These results suggest the usefulness of measuring saccadic eye movements using TEL for assessing the recovery of equilibrium following IVS, even in patients treated with flumazenil.