Visual evaluation of fade in response to facial nerve stimulation at the eyelid.

Abstract Study Objective The aim of this study is to investigate the probability of visual detection of fade in response to train-of-four (TOF) stimulation, double-burst stimulation 3,3 (DBS 3,3 ), or DBS 3,2 at the eyelid in comparison to that at the thumb. Design This is a randomized single-blinded study. Setting The study took place at the University hospital. Patients and Measurements Sixty adult patients underwent general anesthesia. Interventions and Measurements Patients were randomly divided into either the eyelid group (n = 30) or the thumb group (n = 30). In the eyelid group, at the varying degrees of neuromuscular block caused by vecuronium, TOF, DBS 3,3 , or DBS 3,2 were given at the temporal branch of the facial nerve, and the probability of visual detection of fade in response to TOF, DBS 3,3 , or DBS 3,2 was determined at the eyelid. Similarly, in the thumb group, the probability of visual detection of fade in response to TOF, DBS 3,3 , or DBS 3,2 was examined at the thumb. Main Results When the true TOF ratios were 0 to 0.60, the probability of detection of TOF fade in the eyelid group was significantly lower than in the thumb group ( P 3,3 fade in the eyelid group was significantly less than in the thumb group ( P 3,2 fade in the eyelid group was significantly higher than in the thumb group ( P Conclusion The probability of visual detection of fade in response to TOF or DBS 3,3 is lower at the eyelid than the thumb. In contrast, DBS 3,2 fade tends to be seen more frequently at the eyelid than at the thumb.