No abstract available.
Intubation ; Neuromuscular Blockade ; Neuromuscular Blocking Agents

This paper presents an echo of what transpired during the meeting written in a question ans answer format.
MUSCLE RELAXANTS, CENTRAL ; NEUROMUSCULAR BLOCKADE ; NEUROMUSCULAR AGENTS

No abstract available.
Humans ; Neuromuscular Blockade* ; Neuromuscular Blocking Agents*

BACKGROUND: It has long been held that antiepileptics reduce the duration of action, and increase the requirement for, neuromuscular blocking agents. However, levetiracetam, a relatively novel antiepileptic agent, possesses different pharmacokinetic properties to other, conventional antiepileptics, such that its effect on neuromuscular blocking agents might also differ. The purpose of this retrospective study is to investigate the effect of levetiracetam on the clinical duration of rocuronium. METHODS: In this study, the duration of neuromuscular blockade induced by rocuronium was compared between control and levetiracetam-receiving groups. The data were retrieved from one of our previous studies. RESULTS: The control and levetiracetam groups comprised 16 and 13 patients, respectively, all of whom underwent cerebrovascular surgery. Subjects received supplementary rocuronium (0.15 mg/kg) whenever the train-of-four count reached 2 during surgery. The interval between supplementary rocuronium (0.15 mg/kg) injections was significantly longer in the levetiracetam vs. control group (50 and 39 minutes, respectively; P = 0.036). CONCLUSIONS: The present results challenge the convention that antiepileptics decrease the duration of action of neuromuscular blockers, thereby alerting clinicians to the possibility of prolonged neuromuscular blockade in patients taking levetiracetam. Anesthetic management should encompass careful neuromuscular monitoring in such patients.
Anticonvulsants ; Humans ; Neuromuscular Blockade ; Neuromuscular Blocking Agents ; Neuromuscular Monitoring ; Neuromuscular Nondepolarizing Agents ; Retrospective Studies

BACKGROUND: Previous studies reported the lack of interaction between propofol and neuromuscular blockers. The current study was designed to compare the influence of propofol to that of enflurane on the vecuronium. METHODS: Forty , either sex, adult patients, scheduled for elective surgery, were randomly assigned to two groups. Patients received either propofol (Group I n=20) or thiopental (Group II n=20) as an induction agent and anesthesia were maintained with either propofol-N2O-O2(Group I) or enflurane- N2O-O2(Group II). Before induction, initial twitch was obtained as a control with supramaximal stimulus. Neuromuscular contraction was monitored continuously and recorded on a relaxograph. Onset time (T0), clinical duration (T25), and recovery index (RI) were measured. RESULTS: Onset time and clinical duration of vecuronium were not significantly different between two groups. Mean recovery index was 18.5 min and 38.6 min in group Iand II, respectively. CONCLUSION: These results indicated that propofol, different from enflurane, did not have influence on the recovery index of vecuronium.
Adult ; Anesthesia ; Anesthetics ; Enflurane* ; Humans ; Neuromuscular Agents* ; Neuromuscular Blockade ; Neuromuscular Blocking Agents ; Propofol* ; Thiopental ; Vecuronium Bromide*

BACKGROUND: There were many reports about the effect of succinylcholine on the action of nondepolarizing muscle relaxants. The results are inconsistent depend on the nondepolarizing muscles relaxants used, time when nondepolarizing blockers administered and methods of experiments etc. We investigated the effect of succinylcholine on the neuromuscular blockade induced with mivacurium, a new short acting nondepolarizing muscle relaxant, when mivacurium was administered during early and late recovery from succinylcholine block and when different dose of succinylcholine were used. METHODS: 30 rabbits were divided into 5 groups including control group. Control group was administered mivacurium only. In other 2 groups, succinylcholine (3xED95) was administered, and mivacurium was given at 5% and 100% recovery from succinylcholine. In the other two groups, succinylcholine (6xED95) was administered, and mivacurium was given at 5% and 100% recovery from succinylcholine. We investigated onset time, duration of relaxation, and recovery index of mivacurium induced neuromuscular block. RESULTS: Onset time was shortened in all groups compare to control group. Duration and recovery index were not changed significantly at 5% and 100% recovery of succinylcholine (3xED95) administered group, but prolonged significantly (p<0.05) in succinylcholine (6xED95) administered groups compare to control group. CONCLUSION: Mivacurium induced block were more prolonged at 100% recovery of succinylcholine (3xED95) induced block and these effect were more potentiated by the increasing the dose of succinlycholine (6xED95) administered group.
Muscles ; Neuromuscular Blockade* ; Neuromuscular Nondepolarizing Agents ; Rabbits ; Relaxation ; Succinylcholine*

No abstract available.
Anaphylaxis* ; Androstanols ; Humans ; Neuromuscular Blockade* ; Neuromuscular Blocking Agents*

BACKGROUND: The train of four (TOF) stimulation is valuable to study pharmacodynamics associated with the interaction between muscle relaxants and receptors in the neuromuscular junction. TOF fade expresses presynaptic effect diminished output of transmitters. The aim of this study was to examine differences in presynaptic effects of different relaxants by measuring the TOF ratio during the onset and offset of block. METHODS: Eighty four healthy adult patients of ASA grades I or II were included in the study. The muscle relaxants studied were vecuronium (0.08 mg/kg), atracurium (0.5 mg/kg), mivacurium (0.15 mg/kg), rocuronium (0.6 mg/kg) and succinylcholine (1.0 mg/kg, 0.1 mg/kg, 0.2 mg/kg, 0.4 mg/kg). The TOF ratios were measured at approximate height of first response in the TOF (T1) of 75, 50 and 25% during onset and offset. Especially its ratios were measured at first depress of T1 during onset and its corresponding T1 during offset following administration of subclinical doses of succinylcholine. RESULTS: In the non-depolarizing muscle relaxants, TOF fade is more evident during offset than onset (p<0.05). The extent of fade varies between muscle relaxants. The greatest TOF fade has been shown in rocuronium during onset. In the succinylcholine, the TOF fade is apparent during onset and related to doses given (p<0.05). However the significant TOF fade is not seen during offset. CONCLUSIONS: All muscle relaxants, including both depolarizing and nondepolarizing agent, have predominantly postsynaptic and presynaptic effects. Furthermore, the fact that moderate TOF fade after subclinical doses of succinylcholine occurred obviously during onset of block is possibly indicating a greater presynaptic receptor blocking action.
Adult ; Atracurium ; Humans ; Neuromuscular Blockade* ; Neuromuscular Blocking Agents* ; Neuromuscular Junction ; Neuromuscular Nondepolarizing Agents ; Receptors, Presynaptic ; Succinylcholine ; Vecuronium Bromide

BACKGROUND: The effect of dexamethasone injection on cisatracurium-induced neuromuscular block was compared according to different injection time points. METHODS: One hundred seventeen patients were randomly assigned to three groups: 8 mg of dexamethasone injected intravenously 2–3 h before anesthesia (group A), just before anesthesia induction (group B), and at the end of surgery (control group). Three minutes after anesthesia induction, intubation was performed without neuromuscular blockers, and acceleromyography was initiated. All patients received 0.05 mg/kg cisatracurium; the onset time and recovery profiles were recorded. RESULTS: Eighty patients were finally enrolled. The onset time (median [interquartile range], seconds) was significantly hastened in group A (520.0 [500.0–560.0], n = 30) compared to that in group B (562.5 [514.0–589.0], n = 22) (P = 0.008) and control group (586.5 [575.0–642.5], n = 28) (P < 0.001). The onset time in group B was faster than the control group (P = 0.015). The recovery time [mean (95% CI) minutes] was significantly hastened in group A [28.5 (27.3–29.6)] compared to that in group B [32.3 (31.0–33.6)] (P < 0.001) and control group [30.9 (29.9–31.8)] (P = 0.015). The total recovery time was significantly hastened more in group A [47.1 (45.5–48.6)] than group B [52.8 (51.6–54.0) minutes] (P < 0.001) and control group [50.5 (48.7–52.3) minutes] (P = 0.008). CONCLUSIONS: A single dose of 8 mg of dexamethasone hastened the onset and total recovery times of cisatracurium-induced block by approximately 15 and 9%, respectively if administered 2–3 h prior to surgery.
Anesthesia ; Dexamethasone* ; Humans ; Intubation ; Neuromuscular Blockade ; Neuromuscular Blocking Agents ; Neuromuscular Monitoring

Administration of a subparalytic dose of a nondepolarizing muscle relaxant prior to intubating dose hastens the onset time of neuromuscular blockade. This study was designed to investigate the influence of a priming dose of vecuronium (0.015 mg/kg) and d-tubocurarine (0.05 mg/kg) on intubating dose of vecuronium (0.085 mg/kg). The authors measured TOF ratio using neuromuscular monitoring. This monitoring was carried out by stimulation of ulnar nerve at a frequency of 2Hz every 20 seconds using Datex relaxograph to measure the compound evoked electrographic response of hypothenar muscle. The patients were randomly divided into two groups as priming dose ; vecuronium and dtubocurarine (DTC) group respectively. Mixture of two different nondepolarizing muscle relaxant may produce synergism, although the reason for this synergism is unknown. It may be the results of the action of the drugs at different sites. In our study, we found the results as follows ;1) The rapid onset was occured with d-tubocurarine(0.05 mg/kg) as priming drug than vecuronium (0.015 mg/kg) 2) The duration was longer when d-tubocurarine was used (P<0.05) The authors conclude that the onset is more rapid and the duration is longer when other species of nondepolarizing muscle relaxant is used than same agent is used as priming drug.
Humans ; Neuromuscular Blockade* ; Neuromuscular Blocking Agents ; Neuromuscular Monitoring ; Tubocurarine* ; Ulnar Nerve ; Vecuronium Bromide*