Conventional neuromuscular monitoring versus acceleromyography: it's not the monitor but the anesthetist.

摘要

To the Editor:-In the September issue of Anesthesiology, Murphy et al. demonstrated that residual neuromuscular blockade may produce adverse respiratory outcomes. We believe that the methodology used in their study is significantly flawed, and that their conclusions comparing qualitative (conventional nerve stimulators) and quantitative (acceleromyography) monitoring are not supported by their results. In our opinion, their study failed to demonstrate that quantitative monitoring is superior to qualitative monitoring in reducing the incidence of adverse respiratory events in the perioperative period.Naguib et al. have written: "(In neuromuscular blockade studies,) nuances in protocol and apparently 'minor' variations in methodology may markedly affect outcome." We find three types of faults with the present methodology. First, they used visual rather than tactile evaluation of train-of-four (TOF) responses. The present study, involving 20 faculty and 50 residents and nurse anesthetists, and similar papers from the same institution indicate that they routinely produce a level of blockade which results in two to three visual TOF responses. This practice is based upon an early study comparing electromyogram findings with a single surgeon's subjective evaluation of abdominal relaxation. We believe that evaluating visual as compared to tactile TOF responses tends to underestimate the level of blockade and overestimate the amount of recovery. We have observed patients with 4/4 visual and simultaneous 0/4 tactile TOF responses.