Comparison of neuromuscular action of rocuronium, a new steroidal non-depolarizing agent, with vecuronium.
BACKGROUND
Rocuronium is a new nondepolarizing muscle relaxant. It features a rapid onset and lack of histamine release: It has an intermediate onset of action as vecuronium. The purpose of this study was to compare the neuromuscular action and condition of intubation after a bolus dose of rocuronium or vecuronium (2 x ED90). We also compared the duration of relaxation after intubation and maintenance doses of each drug.


METHODS
Sixty male or female patients, age 18-65, scheduled for elective surgery under general anesthesia were divided randomly into two groups (rocuronium and vecuronium group). All patients were ASA class I-II and pre-operative laboratory data were normal. Anesthesia was performed with fentanyl, isoflurane and O2. Rocuronium 0.6 mg/kg (2 x ED90) or vecuronium 0.1 mg/kg (2 x ED90) was given during induction of anesthesia. The response of adductor pollicis was measured with acceleromyography. Neuromuscular block was maintained by bolus injection of rocuronium 0.15 mg/kg or vecuronium 0.025 mg/kg when T1 reached 25% of control. Onset time, duration, recovery indices, intubation condition and T4/T1 ratio to 70% were recorded. Side effects were recorded during the study.


RESULTS
The onset time was significantly longer in vecuronium group than that of rocuronium group (102.8 +/- 26.9 s vs. 54.9 +/- 10.9 s, p < 0.05). The clinical durations of action were respectively 44.2 +/- 13.2 min in rocuronium group and 42.5 +/- 9.1 min in vecuronium group (T1 to 25%). The duration of the maintenance were respectively 28.8 +/- 9.5 min in rocuronium group and 26.1 +/- 6.8 min in vecuronium group (T1 to 25%). No adverse effect occurred with either drug. The intubation condition was similar in both groups.


CONCLUSIONS
We conclude that rocuronium provides a more rapid onset of action than that of vecuronium. Rocuronium is an intermediate-acting muscle relaxant as vecuronium with good to excellent intubation condition. It may be an useful alternative to vecuronium for rapid tracheal intubation.
Lin
P L
PL
Department of Anesthesiology, National Taiwan University Hospital, R.O.C.
Liu
C C
CC
Fan
S Z
SZ
Chao
A
A
Shin
S C
SC
Tai
Y T
YT
D000293:Adolescent; D000328:Adult; D000368:Aged; D000732:Androstanols / Q000494:pharmacology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009467:Neuromuscular Depolarizing Agents / Q000494:pharmacology*; D000077123:Rocuronium; D014673:Vecuronium Bromide / Q000494:pharmacology*
D000732:Androstanols; D009467:Neuromuscular Depolarizing Agents; D014673:Vecuronium Bromide; D000077123:Rocuronium