The accelerometry(AMG) muscle relaxant monitor is the most widely used quantitative muscle relaxant monitor to assess the degree of neuromuscular at present. In this study, the ulnar nerve was stimulated by using train of four stimulation(TOF) mode of the AMG muscle relaxant monitor, and the movement of the adductor pollicis muscle was monitored. In this way, the distribution range of key parameters (acceleration peak value, response time, and TOF ratio) of the adductor pollicis muscle during the use of muscle relaxant in clinical practice is analyzed and will provide a practical basis for the development and improvement of the muscle relaxant monitor.
Electric Stimulation ; Muscle, Skeletal ; Neuromuscular Blockade ; Neuromuscular Nondepolarizing Agents ; Ulnar Nerve/physiology*

Objective To investigate diabetes-mediated changes in the neuromuscular pharmacodynamics of rocuronium in rats. Methods Diabetes mellitus was induced by a single injection of streptozotocin in rats.A total of 24 male SD rats were assigned to four groups using random number table:the normal control group,diabetic 2-week group,diabetic 4-week group,and diabetic 8-week group(6 rats per group).The sciatic nerve was stimulated in a rain-of-four(TOF)pattern,and the twitch tension changes in the tibialis anterior muscle were demonstrated by mechanomyography after intravenous injection of rocuronium in vivo.The time course characteristics of rocuronium,including onset time,and the recovery time from rocuronium injection to TOF ratio 75%(RT75%)and 90%(RT90%),were recorded,and half maximal inhibitory concentration(IC)values of rocuronium were determined using a four-parameter dose response curve. Results Compared with the normal controls,the diabetic rats had significantly prolonged onset time of rocuronium,while the RT75% and RT90% were decreased at all rocuronium doses(P<0.001).The time course changes became increasingly significant as the duration of diabetes lengthened(P<0.001).The IC and 95% confidence interval values for rocuronium in the normal control group,diabetic 2-week group,diabetic 4-week group,and diabetic 8-week group were 0.37(0.35-0.38)mg/kg,0.44(0.43-0.46)mg/kg,0.59(0.57-0.61)mg/kg,and 0.64(0.61-0.66)mg/kg,respectively.IC values were significantly higher in the diabetic groups vs.normal control(P<0.001)and gradually increased as the duration of diabetes lengthened(P<0.001).Conclusion Diabetes is associated with the rat skeletal muscle hyposensitivity to rocuronium,which is featured by prolonged onset time of rocuronium,decreased RT 75% and RT 90%,and right shift of the cumulative dose-response curve of rocuronium.
Animals ; Diabetes Mellitus, Experimental ; physiopathology ; Male ; Muscle, Skeletal ; drug effects ; Neuromuscular Nondepolarizing Agents ; pharmacology ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Rocuronium ; pharmacology

OBJECTIVE: To determine the maximum dose of continuously infused mivacurium for intraoperative neuromonitoring and observe its adverse effects in thyroid surgery. METHODS: Twenty-eight patients undergoing thyroid surgery with intraoperative neuromonitoring received continuous infusion of mivacurium at the initial rate of 5.43 μg?kg?min, and the infusion rate for the next patient was adjusted based on the response of the previous patient according to the results of neurological monitoring. The depth of anesthesia was maintained with sevoflurane and remifentanil during the surgery. The LD50 and 95% of mivacurium were calculated using Brownlee's up-and-down sequential method. RESULTS: The LD50 of continuously infused mivacurium was 8.94 μg?kg?min (95% : 8.89- 8.99 μg?kg?min) during thyroid surgery, which did not affect neurological function monitoring. Transient chest skin redness occurred after induction in 9 patients (32.1%). None of the patients experienced intubation difficulties or showed intraoperative body motions during the surgery. CONCLUSIONS In patients undergoing thyroid surgery under anesthesia maintained by inhalation and intravenous infusion, the LD50 of mivacurium was 8.94 μg?kg?min (95% : 8.89-8.99 μg?kg?min) for continuous infusion, which does not cause serious adverse effects during the operation.
Anesthesia ; Anesthetics, Inhalation ; Anesthetics, Intravenous ; Humans ; Intraoperative Neurophysiological Monitoring ; methods ; Lethal Dose 50 ; Mivacurium ; administration & dosage ; adverse effects ; Neuromuscular Nondepolarizing Agents ; administration & dosage ; adverse effects ; Remifentanil ; Sevoflurane ; Thyroid Gland ; surgery

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: Several types of receptors are found at neuromuscular presynaptic membranes. Presynaptic inhibitory A1 and facilitatory A2A receptors mediate different modulatory functions on acetylcholine release. This study investigated whether adenosine A1 receptor agonist contributes to the first twitch tension (T1) of train-of-four (TOF) stimulation depression and TOF fade during rocuronium-induced neuromuscular blockade, and sugammadex-induced recovery. METHODS: Phrenic nerve-diaphragm tissues were obtained from 30 adult Sprague-Dawley rats. Each tissue specimen was randomly allocated to either control group or 2-chloroadenosine (CADO, 10 μM) group. One hour of reaction time was allowed before initiating main experimental data collection. Loading and boost doses of rocuronium were sequentially administered until > 95% depression of the T1 was achieved. After confirming that there was no T1 twitch tension response, 15 min of resting time was allowed, after which sugammadex was administered. Recovery profiles (T1, TOF ratio [TOFR], and recovery index) were collected for 1 h and compared between groups. RESULTS: There were statistically significant differences on amount of rocuronium (actually used during experiment), TOFR changes during concentration-response of rocuronium (P = 0.04), and recovery profiles (P < 0.01) of CADO group comparing with the control group. However, at the initial phase of this experiment, dose-response of rocuronium in each group demonstrated no statistically significant differences (P = 0.12). CONCLUSIONS: The adenosine A1 receptor agonist (CADO) influenced the TOFR and the recovery profile. After activating adenosine receptor, sugammadex-induced recovery from rocuronium-induced neuromuscular block was delayed.
2-Chloroadenosine ; Acetylcholine ; Adenosine* ; Adult ; Data Collection ; Depression ; Humans ; Membranes ; Neuromuscular Blockade* ; Neuromuscular Junction ; Neuromuscular Nondepolarizing Agents ; Rats, Sprague-Dawley ; Reaction Time ; Receptor, Adenosine A1 ; Receptors, Purinergic P1*

BACKGROUND: We investigated the hypothesis that pretreatment with nefopam 20 mg would influence the onset and recovery profiles of rocuronium-induced neuromuscular block. METHODS: After Institutional Review Board approval, 134 patients, aged between 20–65 years, belonging to the American Society of Anesthesiologists physical status classification I or II, were randomly allocated to receive either 0.9% normal saline (control group) or nefopam 20 mg (nefopam group), infused over one hour before induction of anesthesia. Anesthesia was induced with remifentanil and propofol, followed by endotracheal intubation with rocuronium 0.6 mg/kg. We recorded the lag time, onset time, clinical duration, recovery index, recovery time, and total recovery time. RESULTS: We included 111 patients in the final analysis. The lag time, onset time, clinical duration, recovery index, recovery time, and total recovery time of the nefopam group (n = 57) were not significantly different compared with that of the control group (n = 54). CONCLUSIONS: Pretreatment with nefopam 20 mg one hour before induction of anesthesia does not have a significant influence on the onset and recovery profiles of rocuronium-induced neuromuscular block.
Anesthesia ; Classification ; Drug Interactions ; Ethics Committees, Research ; Humans ; Intubation, Intratracheal ; Nefopam* ; Neuromuscular Blockade* ; Neuromuscular Monitoring ; Neuromuscular Nondepolarizing Agents ; Propofol ; Prospective Studies*

BACKGROUNDThe antagonistic actions of anticholinesterase drugs on non-depolarizing muscle relaxants are theoretically related to the activity of acetylcholinesterase (AChE) in the neuromuscular junction (NMJ). However, till date the changes of AChE activity in the NMJ during sepsis have not been directly investigated. We aimed to investigate the effects of sepsis on the antagonistic actions of neostigmine on rocuronium (Roc) and the underlying changes of AChE activity in the NMJ in a rat model of cecal ligation and puncture (CLP).

METHODSA total of 28 male adult Sprague-Dawley rats were randomized to undergo a sham surgery (the sham group, n = 12) or CLP (the septic group, n = 16). After 24 h, the time-response curves of the antagonistic actions of 0.1 or 0.5 μmol/L of neostigmine on Roc (10 μmol/L)-depressed diaphragm twitch tension were measured. Meanwhile, the activity of AChE in the NMJ was detected using a modified Karnovsky and Roots method. The mRNA levels of the primary transcript and the type T transcript of AChE (AChET) in the diaphragm were determined by real-time reverse transcription-polymerase chain reaction.

RESULTSFour of 16 rats in the septic group died within 24 h. The time-response curves of both two concentrations of neostigmine in the septic group showed significant upward shifts from those in the sham group (P < 0.001 for 0.1 μmol/L; P = 0.009 for 0.5 μmol/L). Meanwhile, the average optical density of AChE in the NMJ in the septic group was significantly lower than that in the sham group (0.517 ± 0.045 vs. 1.047 ± 0.087, P < 0.001). The AChE and AChETmRNA expression levels in the septic group were significantly lower than those in the sham group (P = 0.002 for AChE; P = 0.001 for AChET).

CONCLUSIONSSepsis strengthened the antagonistic actions of neostigmine on Roc-depressed twitch tension of the diaphragm by inhibiting the activity of AChE in the NMJ. The reduced content of AChE might be one of the possible causes of the decreased AChE activity in the NMJ.

Acetylcholinesterase ; metabolism ; Androstanols ; pharmacology ; Animals ; Cecum ; injuries ; Cholinesterase Inhibitors ; pharmacology ; Diaphragm ; drug effects ; metabolism ; Disease Models, Animal ; Ligation ; Male ; Neostigmine ; pharmacology ; Neuromuscular Junction ; enzymology ; Neuromuscular Nondepolarizing Agents ; pharmacology ; Punctures ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Sepsis ; physiopathology

The anticholinesterase pyridostigmine is usually used as a reversal agent of non-depolarizing muscle relaxants in general anesthesia. Most adverse muscarinic effects of anticholinesterases are controlled by anticholinergics; however, there is still a potential for fatal cardiac complications. We report a case of cardiac arrest associated with coronary vasospasm that developed during emergence from general anesthesia in a 61-year-old male patient undergoing uvulopalatopharyngoplasty with preoperatively undiagnosed coronary vasospastic angina. Anticholinesterases should be administered with caution for neuromuscular blockade reversal, especially in patients with coronary vasospastic angina.
Anesthesia, General ; Cholinergic Agents ; Cholinergic Antagonists ; Cholinesterase Inhibitors ; Coronary Vasospasm ; Heart Arrest* ; Humans ; Male ; Middle Aged ; Muscle Relaxation* ; Neuromuscular Blockade ; Neuromuscular Nondepolarizing Agents ; Pyridostigmine Bromide*

The hypothesis of this study was that diabetes-induced desensitization of rat soleus (SOL) and extensor digitorum longus (EDL) to non-depolarizing muscle relaxants (NDMRs) depends on the stage of diabetes and on the kind of NDMRs. We tested the different magnitude of resistance to vecuronium, cisatracurium, and rocuronium at different stages of streptozotocin (STZ)-induced diabetes by the EDL sciatic nerve-muscle preparations, and the SOL sciatic nerve-muscle preparations from rats after 4 and 16 weeks of STZ treatment. The concentration-twitch tension curves were significantly shifted from those of the control group to the right in the diabetic groups. Concentration giving 50% of maximal inhibition (IC50) was larger in the diabetic groups for all the NDMRs. For rocuronium and cisatracurium in both SOL and EDL, IC50 was significantly larger in diabetic 16 weeks group than those in the diabetic 4 weeks group. For SOL/EDL, the IC50 ratios were significantly largest in the diabetic 16 weeks group, second largest in the diabetic 4 weeks group, and smallest for the control group. Diabetes-induced desensitization to NDMRs depended on the stage of diabetes and on the different kind of muscles observed while was independent on different kind of NDMRs. The resistance to NDMRs was stronger in the later stage of diabetes (16 versus 4 weeks after STZ treatment). Additionally, when monitoring in SOL, diabetes attenuated the actions of neuromuscular blockade more intensely than that in EDL. Nonetheless, the hyposensitivity to NDMRs in diabetes was not relevant for the kind of NDMRs.
Animals ; Diabetes Mellitus, Experimental* ; Inhibitory Concentration 50 ; Muscles* ; Neuromuscular Blockade ; Neuromuscular Junction ; Neuromuscular Nondepolarizing Agents ; Rats* ; Streptozocin ; Vecuronium Bromide

BACKGROUND: Rapid sequence induction (RSI) is indicated in various situations. Succinylcholine has been the muscle relaxant of choice for RSI, and rocuronium has become an alternative medicine for patients who cannot be administered succinylcholine for various reasons. Although rocuronium has the most rapid onset time among non-depolarizing muscle relaxants, the standard dose of rocuronium (0.6 mg/kg) takes 60 seconds to achieve appropriate muscle relaxation. We evaluated intubating conditions using the "modified timing principle" with rocuronium and succinylcholine. METHODS: In this prospective controlled blinded study, all patients received 1.5 microg/kg fentanyl intravenously with preoxygenation for 2 minutes and were randomized to receive 0.6 mg/kg rocuronium followed by 1.5 mg/kg propofol or 1.5 mg/kg propofol and 1.5 mg/kg succinylcholine. The rocuronium group was intubated just after confirming loss of consciousness, and the succinylcholine group was intubated 1 minute after injecting succinylcholine. Intubation condition, timing of events, and complications were recorded. RESULTS: All patients were successfully intubated in both groups. Apnea time of the rocuronium group (38.5 seconds) was significantly shorter than that in the succinylcholine group (100.7 seconds). No significant differences were observed in loss of consciousness time or intubation time. The succinylcholine group tended to show better intubation conditions, but no significant difference was observed. None of the patients complained awareness of the intubation procedure or had respiratory difficulty during a postoperative interview. CONCLUSIONS: The modified RSI with rocuronium showed shorter intubation sequence, acceptable intubation conditions, and a similar level of complications compared to those of conventional RSI with succinylcholine.
Androstanols ; Apnea ; Complementary Therapies ; Fentanyl ; Humans ; Intubation ; Muscle Relaxation ; Muscles ; Neuromuscular Nondepolarizing Agents ; Propofol ; Prospective Studies ; Succinylcholine ; Unconsciousness