We thank Dr. Todd  for his interest in our article, “Comparison of Contralateral Acceleromyography and Electromyography for Posttetanic Count Measurement.”  In clinical practice, numerous acceleromyography devices measuring acceleration of muscle movement and recently developed electromyography devices measuring evoked muscle complex action potentials are used for quantitative neuromuscular monitoring. However, anesthesiologists are usually not aware of each device’s algorithms. Moreover, research data, such as comparing agreements between each device and mechanomyography or between each device including a comparison with tactile or visual response of twitch for train-of-four count and ratio or posttetanic count, are very limited. Therefore, this leaves us uncertain as to which equipment is most accurate and suitable for neuromuscular monitoring. Along with previous studies our study has presented essential and important data in the field of neuromuscular research, and I believe that more similar active studies should be conducted.

When comparing devices or comparing devices with the visible or tactile response for the weak response that appears as the twitch response gradually decreases, we totally concur with Dr. Todd’s comment that “a twitch is not always a twitch.” The comparison results may vary, not only between devices using different technologies in the twitch measurement, but also between devices using the same technology with different algorithms by manufacturers.  Therefore, the study results cannot be generalized under the name of acceleromyography or electromyography. Thus, in the conclusion section of our article, the name of the equipment was specified as follows: “In conclusion, this observational study demonstrated that acceleromyography (Philips IntelliVue) frequently counted more twitches than electromyography (TwitchView) in posttetanic count monitoring.” To the best of our knowledge, the software version of the equipment was not specified in previous studies, and Dr. Todd recommends specifying the software versions along with the device names, which are as follows: Philips IntelliVue (software version A.00.10; Philips Healthcare, The Netherlands) and TwitchView (software version 1.0.52; Blink Device Company, USA).

Recently, during and after general anesthesia using neuromuscular blocking agents, quantitative neuromuscular monitoring is strongly recommended. The use of quantitative neuromuscular monitors based on various technologies and different algorithms is increasing in clinical practice. Therefore, understanding of the characteristics of each device and consideration of the results of comparative studies among the devices are warranted.