It is a well-known fact that various inhalation anesthetics augment neuromuscu/ar block produced by nondepolarizing neuromuscu/ar blocking agents to varying degrees. There are only a few reports concerning the inftuence of inhalation anesthetics on the neuromuscular blocking action of rocuronium. The purpose of this investigation is to determine the effects of halothane, isoflurane and sevofturane anesthesia on neuromuscular blocking effect of rocuronium.
Following approval from our ethic comittee, 30 ASA /-// patients of either sex, aged 23-70 years old, were scheduled for elective surgery. Patients were randomly allocated to three groups. Induction of anesthesia was performed 6 mg/kg of thiopental and 0.6 mg/kg of rocuronium, 1 ug/kg of fentanyl, 1 mg/kg of lidocaine and maintained by 66 % nitrous oxide and halothane (0.8 %) in oxygene in group I, isoflurane (1.2 %) in group II and sevoflurane (1.7 %) in group III. The EMG response of the adductor pollicis was monitored by TOF-Guard stimulator (Biometer). 60 seconds after the administration of rocuronium 0.6 mg/kg IV endotracheal intubation was performed and intubation conditions were assessed and scored as excellent, good, poor and inadequate. Following intubation, whenever T} returned to 25% control additional doses of rocuronium was given (0.2 mg/kg). The onset time (T1max), duration of block (Tı 25 %), recovery times (Tt 75 % -25 %) were the parameters measured.
The results were analyzed with Kruskal-Wallis and Analysis of variance tests. Comparing halothane, isoflurane and sevoflurane groups, there were no statisticafly significant differences betvveen their effects on the onset time and duration of block with rocuronium (p>0.05). Only recovery times were different in three groups. Recovery in sevoflurane group was longer than the other two groups. Halothane group had the shortest recovery from neuromuscular block with rocuronium(p