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

Comflicting results have been reported on whether ketamine potentiates the neuromuscular effect of succinylcholine or other non-depolarizing agents. Notably, there has been no reported clinical evatuation of the influence of ketamine upon the neuromuscular action of vecuronium a new muscle relaxant. The present study was undertaken to estimate the influence of ketamine upon the neuromuscular action of vecuronium with a single bolus injection of ED95. Forty-five ASA class l or ll surgical patients were divided into three groups: l, ll and lll and were given thiopental sodium(5mg/kg), ketamine 3mg/kg and ketamine 5mg/kg as induction agents, respectively. The duration and recovery index of group ll and lll (35.20+/-2.30 and 16.20+/-1.37 min., 52.60+/-3.98 and 25.47+/-3.78min., respectively) were longer than those in group l (24.87+/-1.59 and 10.66 +/- 1.23 min.). But group l had a lower TOF ratio(27.40+/-3.09%) at 75% single twitch recovery than group ll and lll (41.87+/-3.25 and 45.27+/-3.67%, respectively). The increase in duration and the recovery index of group lll were greater than that of group ll. It was concluded that ketamine woudly potentiate the neuromuscular action of vecuronium in a dose-dependent manner. We suggest that combination of ketamine and vecuronium requires careful postoperative neuromuscular monitoring for the recovery from a vecuronium induced neuromuscular block.
Humans ; Ketamine* ; Neuromuscular Agents ; Neuromuscular Blockade* ; Neuromuscular Monitoring ; Succinylcholine ; Thiopental ; Vecuronium Bromide

BACKGROUND: A pneumatic tourniquet is commonly used in orthopedic surgery. However, neuromuscular blocking agent can be sequestered in the isolated limb and be reabsorbed into the systemic circulation after tourniquet release, potentially delaying extubation. To investigate the change in the train-of-four (TOF) ratio after tourniquet release and correlate the TOF ratio change with the extubation time. METHODS: Forty patients undergoing unilateral total knee arthroplasty were enrolled. Before and after the pneumatic tourniquet release, 10 measurements of the TOF ratio were averaged and compared. Additionally, we investigated the correlation between the percentage change in the TOF ratio before and after tourniquet release and the extubation time. RESULTS: Among the 40 patient subjects, 30 showed a TOF ratio before tourniquet release and 10 showed only a TOF count. Of the 30 patients with a TOF ratio, 21 showed a TOF ratio increase after tourniquet release and 9 showed a TOF decrease; both increase and decrease were statistically significant (P < 0.001 and P = 0.008, respectively). The extubation time showed a weak negative correlation with the percentage change in the TOF ratio after tourniquet release (P = 0.004). CONCLUSIONS: In orthopedic surgery using a pneumatic tourniquet, neuromuscular function monitoring may be required to monitor the change in the effect of neuromuscular blocking agent before and after tourniquet release, which may help to improve anesthesia safety.
Anesthesia ; Arthroplasty* ; Extremities ; Humans ; Knee* ; Neuromuscular Blockade ; Neuromuscular Blocking Agents ; Neuromuscular Monitoring ; Orthopedics ; Tourniquets*