The Comparison of the TOF Ratios between Electromyograph and Accelerograph following Vecuronium Administration

Kim, Sung Yell; Jeon, Yong Sub; Kim, Soon Im; Hwang, Kyung Ho; Kim, Sun Chong; Park, Wook

Abstract

The present study was firstly undertaken in an attempt to compare simultaneously EMG(electromyography) and two new ACC(accelerography) reponses in the both hand following vecuronium administration in 26 ASA 1 or 2 adult patients undergoing general anesthesia. In the three NMT monitors, stimulating electrodes are applied similarly over the ulnar nerve on the volar side of the wrist, but the evoked EMG(Relaxograph, Datex Co.) responses obtained from the hypothenar muscles, TOFGUARD(Biometer Co.) responses from adductor pollicis and ParaGraph(Utah Med. Prod. Co.) responses from both muscles of hypothenar and thenar muscle of the hand respectively. Following induction of anesthesia with thiopental sodium(5 mg/kg) and vecuronium(0.08 mg/kg) intravenously, endotracheal intubation was facilitated and anesthesia was maintained with a mixture of enflurane(1~2%) and N2O(50%) . After loss of consciousness, the assessment of the neuromuscular blockade was started. We compared simultaneously TR(train-of-four ratio) responses of EMG at the one hand, and two new ACC named TOF-GUARD and ParaGraph at the other hand respectively during evoked recovery from vecuronium induced neuromuscular blockade. The result was the greater depression of TR response in TOF-GUARD and the lesser depression of TR response in ParaGraph than those in EMG. But test for parallelism did not show a statistically significant difference between the slope of these regression lines. Conclusively, the regression line for TR seems to be tend to give an impression that two new ACC named TOF-GUARD and ParaGraph would be suitable in the assessment of neuromuscular blockade in clinical anesthesia.