PURPOSE: The study was planned to compare the sensitivity of a twitch neuromuscular monitoring test, the train-of-four (TOF), with a tetanic test, double-burst stimulation (DBS), during a subclinical dose of vecuronium. METHODS:Twenty consenting. ASA I patients (16 to 65 years of age) of both sexes were studied. The ulnar nerve was stimulated at the wrist through surface electrodes by Myotest-DBS, and the adductor pollicis response was recorded on Myograph-2000. After stabilization of the twitch tension at titrated supramaximal stimuli (1 Hz), patients were randomly allocated into groups. In group 1 (n=10), the TOF test was monitored; in group 2 (n=10), the DBS test was monitoral. All patients received a priming dose of vecuronium (0.015 mg·kg-1); parameters such asT 1 and TOF ratio (TOFr) (T 4/T 1) were noted in group 1, andD 1 and DBS ratio (DBSr) (D 2/D 1) were noted during the vecuronium effect. RESULTS: The DBS test showed a wider range of change (from control 1.00 to 0.62±0.19 forD 1 and to 0.37±0.14 for DBSr) at a faster rate (0.07±0.04 min-1 forD 1 and 0.08±0.02 min-1 for DBSr) during the block progression phase than the TOF test parameters (T 1 and TOFr). The tetanic fade or DBSr showed peak onset later than peak twitch suppression. The rate of recovery of the DBS test was also slower than that of the TOF test after the peak effect. CONCLUSIONS:DBS is a more sensitive test than TOF to quantify the subclinical dose effect of vecuronium, and among the studied parameters (T 1, TOFr,D 1 and DBSr), DBSr, measuring tetanic fade, was the most sensitive single parameter.
RCT Entities:
PURPOSE: The study was planned to compare the sensitivity of a twitch neuromuscular monitoring test, the train-of-four (TOF), with a tetanic test, double-burst stimulation (DBS), during a subclinical dose of vecuronium. METHODS: Twenty consenting. ASA I patients (16 to 65 years of age) of both sexes were studied. The ulnar nerve was stimulated at the wrist through surface electrodes by Myotest-DBS, and the adductor pollicis response was recorded on Myograph-2000. After stabilization of the twitch tension at titrated supramaximal stimuli (1 Hz), patients were randomly allocated into groups. In group 1 (n=10), the TOF test was monitored; in group 2 (n=10), the DBS test was monitoral. All patients received a priming dose of vecuronium (0.015 mg·kg-1); parameters such asT 1 and TOF ratio (TOFr) (T 4/T 1) were noted in group 1, andD 1 and DBS ratio (DBSr) (D 2/D 1) were noted during the vecuronium effect. RESULTS: The DBS test showed a wider range of change (from control 1.00 to 0.62±0.19 forD 1 and to 0.37±0.14 for DBSr) at a faster rate (0.07±0.04 min-1 forD 1 and 0.08±0.02 min-1 for DBSr) during the block progression phase than the TOF test parameters (T 1 and TOFr). The tetanic fade or DBSr showed peak onset later than peak twitch suppression. The rate of recovery of the DBS test was also slower than that of the TOF test after the peak effect. CONCLUSIONS:DBS is a more sensitive test than TOF to quantify the subclinical dose effect of vecuronium, and among the studied parameters (T 1, TOFr,D 1 and DBSr), DBSr, measuring tetanic fade, was the most sensitive single parameter.