Severity Of Myoclonus Research Articles

Pharmacological interventions for reducing the incidence of myoclonus in patients receiving etomidate for induction of general anesthesia: an umbrella review.

The objective of this umbrella review was to examine various pharmacologic interventions for their potential to reduce etomidate-induced myoclonus. A secondary objective was to compare the relative effectiveness of those medications in reducing the incidence of myoclonus when etomidate is utilized for the induction of general anesthesia. Etomidate is the drug of choice when inducing general anesthesia in hemodynamically unstable patients. However, its use is limited among the general surgical population due to its ability to cause adrenal suppression, vomiting, and myoclonus. Myoclonus can lead to damage of muscle fibers, myalgias, and patient discomfort, and can also be detrimental in patients with low cardiac reserve. Several systematic reviews have reported on the effectiveness of various intravenous medications in reducing mild, moderate, and severe myoclonus; however, a more thorough examination of their influence was lacking. This review included systematic reviews and meta-analyses of randomized controlled trials involving the use of pharmacologic interventions to reduce etomidate-induced myoclonus. Reviews in English and conducted after 1965 were considered for inclusion. A comprehensive search of 11 databases was conducted to identify published and unpublished reviews up to March 2022. Critical appraisal was conducted by 2 independent reviewers using the standardized JBI appraisal tool. Quantitative findings were summarized according to the dose, timing of administration, and relative risk using a data matrix, and were synthesized in tabular format with supporting narrative text. Results were organized by severity of myoclonus (overall, mild, moderate, and severe) and by type of intervention. Eight systematic reviews were included in this umbrella review, which included 48 relevant studies, after removal of duplicates (3909 participants included in the primary studies). Five of the systematic reviews examined the effectiveness of various types of opioids in the prevention of myoclonus, and 3 systematic reviews examined the effectiveness of non-opioid interventions, such as lidocaine, midazolam, and dexmedetomidine. Seven reviews searched at least 4 databases for pertinent studies and specifically indicated that blinded reviewers appraised the articles. All reviews used a published and validated appraisal instrument. The overall quality of all included reviews was judged to be moderate to high. The absolute risk reduction indicating the effectiveness of the prophylactic medications ranged from 47% to 81% for mild, 52% to 92% for moderate, and 61% to 96% for severe myoclonus. Opioids demonstrated the most consistent and substantial effect on the reduction in myoclonus. All pharmacologic interventions identified in this review demonstrated a statistically significant reduction in the incidence of myoclonus. Future studies and reviews should focus on elucidating the particular dose range and timing that is most effective. Anesthesia providers should consider a pre-treatment dose of one of the medications described in this umbrella review as a means to reduce myoclonus and the untoward effects of that condition.

Effect of pre-treatment on induction of anaesthesia with etomidate: A comparison between dexmedetomidine and midazolam–fentanyl combination

Background: Because of its prompt onset of action and clearance, the use of etomidate as an anaesthetic induction agent is increasing in clinical practice. However, etomidate-induced myoclonus (EIM) remains a prevalent issue. Such myoclonic activity can be prevented by the administration of drugs that inhibit subcortical neuronal activity. Aims: This study was designed to compare the effects of pre-treatment with dexmedetomidine and fentanyl–midazolam combination on EIM as well as on attenuation of pharyngolaryngeal reflex. Materials and Methods: One hundred adult patients with the American Society of Anesthesiologists Grades 1 or 2 posted for elective surgery were enrolled and were randomly divided into two groups of 50 patients each. Group D received dexmedetomidine (1 μg/kg) in over 10 min and Group F received midazolam (0.02 mg/kg) + fentanyl (2 μg/kg) intravenously. Haemodynamic variables, incidence and severity of myoclonus were recorded. Results: The incidence of EIM was lower in Group F (26%) when compared to Group D (40%), but the difference was not statistically significant (P = 0.28). Eighteen per cent of the subjects in Group F had Grade 1 myoclonus as compared to 32% of Group D, whereas 8% of the subjects in Group F had Grade 2 myoclonus as compared to 6% of Group D. None of the patients in Group F experienced myoclonus of Grade 3, whereas 2% of the subjects had Grade 3 myoclonus. Conclusion: Administration of a combination of fentanyl and midazolam, along with dexmedetomidine as a pre-treatment, has been found to be an effective strategy for mitigating the incidence of myoclonus.

Low-dose nalmefene pretreatment reduces etomidate-induced myoclonus: A randomized, double-blind controlled trial.

This study compared the effectiveness of nalmefene and fentanyl in reducing the incidence and severity of etomidate-induced myoclonus. One hundred fifty patients were randomized to receive 0.25ug/kg of nalmefene, 1ug/kg of fentanyl, or the same volume of normal saline 3 minutes prior to etomidate-induced anesthesia. The primary observational indexes were the severity level and incidence of etomidate-induced myoclonus, and the secondary observational index included blood pressure, heart rate, and the incidence of adverse effects from anesthesia induction to resuscitation, such as cough, chest wall rigidity, dizziness, nausea, pain after awakening, and intraoperative awareness. The incidence of myoclonus was significantly lower in the nalmefene group (8.0%) than in the fentanyl group (32.0%) (P = .003) and in the normal saline group (72.0%) (P = .000). The severity level of myoclonus in the nalmefene group was significantly lower than the fentanyl group (P = .001) and normal saline group (P = .000). Meanwhile, the incidences of cough and chest wall rigidity during anesthesia induction were significantly lower in the nalmefene group compared with the fentanyl group (P = .003, P = .027). There were no statistically significant differences in heart rate and mean arterial pressure among the 3 gruops (P > .05). There was no difference in the incidence of adverse effects among the 3 groups during recovery from anesthesia (P > .05). Intravenous injection of 0.25ug/kg of nalmefene 3 minutes prior to etomidate is more effective in preventing etomidate-induced myoclonus during general anesthesia than 1ug/kg of fentanyl.

Comparative assessment of dexmedetomidine and butorphanol for attenuation of etomidate-induced myoclonus: A double-blind, randomised controlled study.

Etomidate is a popular induction agent, but its use is associated with myoclonus in 50%-80% of non-premedicated patients. This study aims to compare dexmedetomidine and butorphanol for their relative efficacy in preventing etomidate-induced myoclonus. This randomised study was conducted after obtaining institutional ethical committee clearance and written informed consent from sixty American Society of Anesthesiologists (ASA) I or II consenting patients between 18 and 60 years of age of either sex who had been scheduled for elective surgeries under general anaesthesia. Patients were randomly allocated to dexmedetomidine 0.5 μg/kg (Group D) or butorphanol 0.015 mg/kg (Group B). Both the drugs were given as an infusion over a period of 10 min before induction of anaesthesia. The primary outcome was the incidence of myoclonic movements after etomidate, and the secondary outcomes were the severity of myoclonus, changes in the haemodynamic parameters and incidence of airway complications. Normally distributed variables were compared using Student's t-test, and non-normally distributed variables were compared using Mann-Whitney U test. Qualitative data were analysed using Chi-square/Fisher's exact test. A P-value <0.05 was considered significant. The incidence of etomidate-induced myoclonus was significantly higher in group B compared to group D (P = 0.035). The median (interquartile range [IQR]) of myoclonus grade in patients of group D was 0.00 (0.00-3.00), and group B was 2.50 (0.00-3.00) (P = 0.035). Haemodynamics and airway-related complications were comparable between the groups. Dexmedetomidine was more effective than butorphanol in preventing etomidate-induced myoclonus.

Comparative study of midazolam and fentanyl for the prevention of etomidate-induced myoclonus

Background: Etomidate is one of the popular rapidly acting inducing agents with cardio-stable profile but associated with side effects such as myoclonus. Myoclonus can lead to regurgitation, prolapse of vitreous in open globe or many other complications. Aims and Objectives: The objectives are as follows: To compare the efficacy of Fentanyl and midazolam for prevention of Etomidate induced myoclonus. To study the hemodynamic parameters and side effects of midazolam and fentanyl in patients with myoclonus after etomidate injection. Materials and Methods: Eighty patients scheduled for elective surgeries under general anesthesia were randomly allotted into two groups of 40 patients each. Group F – fentanyl 1 μg/kg and Group M – midazolam 0.03 mg/kg were administered as pre-treatment before induction by Etomidate. After injection of Etomidate, incidence of myoclonus was observed along with the change in hemodynamic parameters (heart rate [HR], systolic blood pressure [SBP], diastolic blood pressure [DBP], and mean arterial pressure [MAP]). Comparison of hemodynamic parameters between 2 groups was done at pre-treatment, 1 min and 2 min after induction and 1 min after intubation. Results: Both fentanyl and midazolam reduced the incidence of myoclonus. However, fentanyl was more effective in decreasing incidence as well severity of myoclonus. Fentanyl was associated with more stable hemodynamic parameters such as HR, SBP, DBP, and MAP 1 min after intubation (P&lt;0.05). In both the groups, there was no increased incidence of PONV. Conclusion: Fentanyl 1 μg/kg or midazolam 0.03 mg/kg can reduce etomidate induced myoclonus. However, fentanyl was more effective in decreasing incidence as well severity of myoclonus and was associated with stable hemodynamic parameters as compared to midazolam.

To study the effect of three different doses of dexmedetomidine as premedication on the incidence and severity of etomidate-induced myoclonus

Background and Aims: Etomidate, a carboxylated imidazole is a rapid-acting nonbarbiturate, nonopioid hypnotic agent that has unique hemodynamic stability, favorable toxic profile, and rapid recovery after a single dose. Myoclonus may occur when etomidate is used for induction of general anesthesia. We tested the hypothesis that premedication with different doses of dexmedetomidine reduces the incidence and severity of myoclonus as well as the side effects induced by etomidate.Materials and Methods: This prospective, randomized, double-blinded study was done on ninety patients undergoing elective surgical procedures who were randomly allocated into three groups for intravenous administration of premedication of 0.3 μg/kg (Group DL), 0.5 μg/kg (Group DM), and 1.0 μg/kg (Group DH) dexmedetomidine in 100 mL normal saline 10 min before induction of general anesthesia with 0.3 mg/kg etomidate. The primary outcome was to evaluate the incidence of etomidate-induced myoclonus, while the severity of etomidate-induced myoclonus and the incidence of adverse effects were taken as secondary outcomes.Results: The incidence of etomidate-induced myoclonus was reduced by 13.3% in Group DL, 36.7% in Group DM, and 56.7% in Group DH. The severity of myoclonus was significantly reduced in Group DH as compared to Group DL and DM (P = 0.001). Side effects such as bradycardia, hypotension, and nausea and vomiting were comparable among the three groups.Conclusion: Premedication with dexmedetomidine 1 μg/kg before induction of general anesthesia not only resulted in a 56.7% reduction in the incidence of etomidate-induced myoclonus but also reduced the severity of myoclonus, without inducing any significant adverse effects, as compared to other two doses.

Dexmedetomidine versus Lignocaine in the Prevention of Etomidate-induced MyoclonusA Randomised Double-blinded Study

Introduction: Etomidate is a preferred induction agent owing to its stable haemodynamic profile, minimal respiratory sideeffects, minimal histamine release, cerebral protection and its property of rapid onset and short duration. However, myoclonus has been reported as one of its side-effects which poses great concern. Amongst the various drugs used to attenuate it, the role of intravenous (i.v.) Dexmeditomidine and Lignocaine have been reported in literature to be of great success. Aim: To compare the efficacy of Dexmedetomidine and Lignocaine in preventing Etomidate-induced Myoclonus. Materials and Methods: The randomised, double blinded study included 104 adult consented patients, of either sex, American Society of Anaesthesiology (ASA) I and II, aged 18-65 years, undergoing routine surgery under general anaesthesia. They were randomly allocated into two groups of 52 patients each viz., Group I receiving 0.5 µg/kg of injection (inj.) Dexmedetomidine i.v. and Group II 1 mg/kg of inj. Lignocaine diluted in 10 mL normal saline i.v. The incidence and severity of myoclonus were assessed and recorded within 90 seconds after etomidate injection using a four point severity scale. The collected data were entered in Statistical Package for Social Sciences (SPSS) version 21.0. Results: Total 104 subjects with the demographic parameters such as age, sex, ASA and weight comparable between the two groups were analysed. Group I recorded lesser number of patients (17, 32.7%) to myoclonus as compared with Group II (21, 40.4%), (p-value=0.41). Maximum patients in Group I developed grade I myoclonus while in Group II, it was grade 2. No patients in Group I developed grade 3 myoclonus as against 5 patients in Group II (p-value=0.03). Conclusion: Dexmedetomidine and Lignocaine were equally effective in the prevention of Etomidate-induced myoclonus but dexmeditomedine was better because of lesser incidence of severe grade myoclonus.

Comparative assessment of different doses of midazolam to prevent etomidate-induced myoclonus – A randomized, double-blind, placebo-controlled trial

Background: Etomidate is a popular induction agent, due to its several advantages for example, an extremely stable hemodynamic profile with no effects on sympathetic nervous system and baroreceptors, minimal effect on respiration and also prevents histamine release in healthy patients or in those with reactive airway disease. It, however, may be associated with myoclonus whose incidence has been reported as 50%–80% in nonpremedicated patients. Ideally, a pretreatment drug for preventing myoclonic movements should be short acting, not have significant effects on respiration and hemodynamics, and not prolong recovery from anesthesia. Midazolam has been used as a pretreatment to attenuate myoclonus in different doses with varied results, but the optimal dose has not been established. The present study was planned to compare the effect of three doses of midazolam, i.e., 0.015 mg/kg, 0.03 mg/kg, and 0.05 mg/kg in preventing etomidate-induced myoclonus.Materials and Methods: This study comprised 164 American Society of Anesthesiologists I/II consenting patients between 18 and 60 years. They were randomly divided into four groups after which pretreatment with normal saline in group M0, midazolam 0.015 mg/kg in group M0.015, 0.03 mg/kg in group M0.03, and 0.05 mg/kg in group M0.05 was administered. The primary outcome was the incidence of myoclonus after etomidate. The secondary outcome measures included severity of myoclonus and changes in hemodynamic parameters. One-way analysis of variance with Bonferroni's correction was used to compare quantitative data. Chi-square test was applied for qualitative data. Further, as there were four groups with multiple comparisons, Bonferroni's correction was applied and P < 0.01 was considered statistically significant.Results: We observed a significant reduction in the incidence of myoclonus of group M0.015 as compared to group M0 (P < 0.001). A significant reduction in severity of myoclonus was observed in all the three midazolam groups compared to the control group (P < 0.001) without any significance among the patients receiving different doses of midazolam.Conclusion: We recommend using midazolam pretreatment in a dose of 0.015 mg/kg for prevention of etomidate-induced myoclonus.

A Comparative Study of Different Doses of Lignocaine on Prevention of Etomidate Induced Myoclonus during Induction of Anesthesia

Abstract Background and Aims Etomidate, an intravenous (IV) induction agent known for its stable myocardial action, can produce myoclonus which can be detrimental for the cardiac patients. Though lignocaine has proven its efficacy in attenuating the etomidate-induced myoclonus, the ideal dose of lignocaine is not known. The aim of our trial was to analyze two different doses of lignocaine on the occurrence and intensity of etomidate induced myoclonus. Materials and Methods A total of 120 patients were randomly assigned into three groups of 40 each. Patients in group A were injected lignocaine 0.5 mg/kg intravenously, group-B patients were injected lignocaine 1 mg/kg intravenously, and group-C patients were injected saline placebo. After 2 minutes, anesthesia was induced with 0.3 mg/kg of etomidate over 30 seconds. The patients were assessed for myoclonus using clinical severity scoring system during first 2 minutes of induction. Our primary outcome was the incidence of myoclonus. The severity of myoclonus and adverse effects were the secondary outcomes. Results No remarkable variation was found regarding demographic profile among three groups. Incidence of myoclonus in groups A and B was 35% and in group C was 98%, the difference being statistically significant. Both doses of lignocaine reduced the severity of myoclonus up to same extent. Conclusion Pretreatment with IV lignocaine 0.5mg/kg and 1 mg/kg IV remarkably decreased the occurrence and severity of myoclonus induced by etomidate up to same extent.

Wearable monitoring of positive and negative myoclonus in progressive myoclonic epilepsy type 1

ObjectiveTo develop and test wearable monitoring of surface electromyography and motion for detection and quantification of positive and negative myoclonus in patients with progressive myoclonic epilepsy type 1 (EPM1). MethodsSurface electromyography and three-dimensional acceleration were measured from 23 EPM1 patients from the biceps brachii (BB) of the dominant and the extensor digitorum communis (EDC) of the non-dominant arm for 48 hours. The patients self-reported the degree of myoclonus in a diary once an hour. Severity of myoclonus with action was evaluated by using video-recorded Unified Myoclonus Rating Scale (UMRS). Correlations of monitored parameters were quantified with the UMRS scores and the self-reported degrees of myoclonus. ResultsThe monitoring-based myoclonus index correlated significantly (p < 0.001) with the UMRS scores (ρ = 0.883 for BB and ρ = 0.823 for EDC) and with the self-reported myoclonus degrees (ρ = 0.483 for BB and ρ = 0.443 for EDC). Ten patients were assessed as probably having negative myoclonus in UMRS, while our algorithm detected that in twelve patients. ConclusionsWearable monitoring was able to detect both positive and negative myoclonus in EPM1 patients. SignificanceOur method is suitable for quantifying objective, real-life treatment effects at home and progression of myoclonus.

To evaluate efficacy of pregabalin for the prevention of etomidate-induced myoclonus: A prospective, randomized, placebo-controlled, double-blind study

Context: The incidence of myoclonus after etomidate induction is 50%–80%. The present study evaluated the efficacy of oral pregabalin for the prevention of etomidate-induced myoclonus. Settings and Design: A prospective, randomized, placebo-controlled, double-blind study. Subjects and Methods: Seventy-four patients of the American Society of Anesthesiologists physical status Grade I or II scheduled for elective surgery under anesthesia were recruited. Following exclusion, 66 patients were randomized into two groups. In Group P patients received pregabalin 150 mg orally 1 h before induction of anesthesia and in Group C patients received placebo tablet. The primary outcome was the incidence and severity of myoclonus. The secondary outcome was the postoperative sedation level. Results: The incidence and severity of myoclonus were significantly decreased in Group P compared with Group C (P 0.05). Conclusion: Pretreatment with pregabalin 150 mg orally reduced the incidence and severity of etomidate-induced myoclonus however incidence of sedation was more.

Pretreatment with dexmedetomidine and magnesium sulphate in prevention of etomidate induced myoclonus - A double blinded randomised controlled trial.

Pretreatment with dexmedetomidine and magnesium sulphate in prevention of etomidate induced myoclonus - A double blinded randomised controlled trial.

Cortico-muscular and cortico-cortical coherence changes resulting from Perampanel treatment in patients with cortical myoclonus

ObjectiveTo investigate the mechanisms by which Perampanel (PER) reduces the severity of action myoclonus, we studied on MEG signals the changes occurring in cortico-muscular coherence (CMC) and cortico-cortical connectivity in patients with progressive myoclonus epilepsies. MethodsThe subjects performed an isometric extension of the hand; CMC and cortico-cortical connectivity were assessed using autoregressive models and generalized partial-directed coherence. The contralateral (Co) sensors showing average CMC values >0.7 of the maximum (set to 1) were grouped as central (C) regions of interest (ROI), while adjacent sensors showing CMC values >0.3 were grouped as Surrounding (Sr) ROIs. ResultsUnder PER treatment, CMC decreased on Co C and Sr ROIs, but also on homologous ipsilateral (Ip) ROIs; out-degrees and betweenness centrality increased in Co ROIs and decreased in Ip ROIs. The flow from Ip to Co ROIs and from activated muscles to Ip C ROI decreased. ConclusionThe improvement of myoclonus corresponded to decreased CMC and recovered leadership of the cortical regions directly involved in the motor task, with a reduced interference of ipsilateral areas. SignificanceOur study highlights on mechanisms suitable to treating myoclonus and suggests the role of a reduced local synchronization together a better control of distant synaptic effects.

Delineating the motor phenotype of SGCE-myoclonus dystonia syndrome

ObjectiveTo perform phenotype and genotype characterization in myoclonus-dystonia patients and to validate clinical rating tools. MethodTwo movement disorders experts rated patients with the Burke-Fahn-Marsden and Unified-Myoclonus rating scales using a video-recording protocol. Clinimetric analysis was performed. SGCE mutations were screened by Sanger sequencing and multiplex ligation-dependent probe amplification. Results48 patients were included and 43/48 rated. Mean age at assessment was 12.9±10.5 years (range 3–51) and 88% were ≤18 years of age. Myoclonus was a universal sign with a rostro-caudal severity-gradient. Myoclonus increased in severity and spread to lower limbs during action tests. Stimulus-evoked myoclonus was observed in 86.8% cases. Dystonia was common but mild. It had a focal distribution and was action-induced, causing writer's cramp (69%) and gait dystonia (34%). The severity of both myoclonus and dystonia had a strong impact on hand writing and walking difficulties.The Unified Myoclonus Rating scale showed the best clinimetric properties for the questionnaire, action myoclonus and functional subscales, and exceeded the Burke-Fahn-Marsden scale in its utility in assessing functional impairment in MDS patients.Twenty-one different SGCE mutations were identified in 45/48 patients, eleven being novel (most prevalent p. Val187*, founder mutation in Canary Islands). ConclusionThis study quantifies the severity of the motor phenotype in SGCE-myoclonus dystonia syndrome, with a special focus on children, and identifies disabilities in gross and fine motor tasks that are essential for childhood development. Our results contribute to the knowledge of SGCE-related MDS in the early stage of evolution, where disease-modifying therapies could be initiated in order to prevent long-term social and physical burdens.

Dissociation in reactive and proactive inhibitory control in Myoclonus dystonia

Myoclonus-dystonia (MD) is a syndrome characterized by myoclonus of subcortical origin and dystonia, frequently associated with psychiatric comorbidities. The motor and psychiatric phenotypes of this syndrome likely result from cortico-striato-thamalo-cerebellar-cortical pathway dysfunction. We hypothesized that reactive and proactive inhibitory control may be altered in these patients. Using the Stop Signal Task, we assessed reactive and proactive inhibitory control in MD patients with (n = 12) and without (n = 21) deep brain stimulation of the globus pallidus interna and compared their performance to matched healthy controls (n = 24). Reactive inhibition was considered as the ability to stop an already initiated action and measured using the stop signal reaction time. Proactive inhibition was assessed through the influence of several consecutive GO or STOP trials on decreased response time or inhibitory process facilitation. The proactive inhibition was solely impaired in unoperated MD patients. Patients with deep brain stimulation showed impairment in reactive inhibition, independent of presence of obsessive–compulsive disorders. This impairment in reactive inhibitory control correlated with intrinsic severity of myoclonus (i.e. pre-operative score). The results point to a dissociation in reactive and proactive inhibitory control in MD patients with and without deep brain stimulation of the globus pallidus interna.

Perampanel for nonepileptic myoclonus in Angelman syndrome

BackgroundAngelman syndrome (AS) is a neurodegenerative disorder caused by functional loss of the maternal ubiquitin-protein ligase 3A gene. Nonepileptic myoclonus, also described as tremulous movement, often occurs during puberty and increases in adulthood. The involuntary movement in AS has not been defined patho-physiologically and the drugs used such as levetiracetam and piracetam are not always effective. Recently, the alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionate (AMPA) receptor antagonist, perampanel (PER), was used to alleviate myoclonus in progressive myoclonus epilepsy. Herein, we tested the efficacy of PER for nonepileptic myoclonus. Methods and resultsFour patients with AS, aged from 20 to 40 years at the beginning of treatment, were enrolled in our study. All patients reported disruption to their daily lives from the myoclonus movement. They experienced mild to moderate improvement with the starting dose of 2 mg. The dose was increased to 4 mg in one patient to achieve sufficient efficacy, while two had their dose reduced to 1 mg due to dizziness or possible exacerbation of myoclonus. The last patient continued to take the starting dose. Follow-up over 16–20 months revealed a significant reduction in the severity of nonepileptic myoclonus in all patients. ConclusionOur study suggests that PER could be one of the promising drugs for nonepileptic myoclonus in AS.

Effect of dexmedetomidine on etomidate-induced myoclonus: a randomized, double-blind controlled trial.

Background: Etomidate used for the induction of general anesthesia can result in myoclonus. We tested the hypothesis that pretreatment with dexmedetomidine (Dex) reduces the incidence of etomidate-induced myoclonus during the induction of general anesthesia.Materials and methods: One hundred patients who were scheduled for selective operations under general anesthesia were included in this randomized, double-blind controlled trial. Patients were randomized to receive either Dex 0.5 µg/kg in 20 mL of normal saline or the same volume of normal saline as pretreatment agents 15 mins before the injection of etomidate 0.3 mg/kg. The primary endpoint was the incidence of etomidate-induced myoclonus. Secondary endpoints were the severity of etomidate-induced myoclonus and the incidence of adverse effects from the onset of action of Dex or normal saline to the injection of etomidate, such as dizziness, respiratory depression, bradycardia, hypotension and nausea/vomiting.Results: All of the 100 patients completed the trial. Dex resulted in a significant 38% reduction in the number of patients who experienced etomidate-induced myoclonus: 13 (26%) vs 32 (64%) (P=0.0001). Additionally, the severity of myoclonus was also reduced in the Dex group than that in the placebo group (P=0.02). Incidence of dizziness, respiratory depression, bradycardia, hypotension and nausea/vomiting was similar in both groups.Conclusions: Pretreatment with Dex 0.5 µg/kg 15 mins before the induction of general anesthesia not only resulted in a 38% reduction in the incidence of etomidate-induced myoclonus, but also reduced the severity of myoclonus, without inducing any adverse effects.

Pretreatment with lidocaine reduces both incidence and severity of etomidate-induced myoclonus: a meta-analysis of randomized controlled trials.

ObjectiveOne conundrum that frequently occurs during clinical anesthesia is etomidate-induced myoclonus, which results in multiple risks. The aim of the study was to evaluate systematically the effect of pretreatment with lidocaine on preventing etomidate-induced myoclonus.Materials and methodsThe literature search was performed from the inception to April 2018 in PubMed, Embase, Cochrane Library, and China National Knowledge Infrastructure. All randomized controlled trials that used lidocaine to prevent etomidate-induced myoclonus were enrolled. The primary outcome included the incidence and severity of etomidate-induced myoclonus. The data were combined to calculate the risk ratio and relevant 95% CI. A meta-analysis was performed following the guidelines of the Cochrane Reviewer’s Handbook and the Preferred Reporting Items for Systematic Reviews and Meta Analyses statement.ResultsA total of eight studies were enrolled, and the existing evidence indicated that 1) pretreatment with lidocaine can reduce the incidence of etomidate-induced myoclonus (the incidence of myoclonus: 37.6% in lidocaine vs 73.6% in saline, risk ratio =0.46, with 95% CI [0.34, 0.63], P<0.0001); 2) the pretreatment with lidocaine can reduce the incidence of mild, moderate, and severe myoclonus; 3) a dose of pretreatment with lidocaine cannot significantly decrease the duration of myoclonus compared to placebo; 4) the administration of lidocaine produced no effect on the stable hemodynamic parameters and no more additional adverse effects.ConclusionPretreatment with lidocaine could be served as one effective approach to decrease both the incidence and the severity of etomidate-induced myoclonus, with limited influence on the hemodynamic stability of patients. However, to confirm precise safety and efficacy of such intervention, more high-quality evidence is necessary.

Comparison of priming versus slow injection for reducing etomidate-induced myoclonus: a randomized controlled study.

BackgroundEtomidate injection is often associated with myoclonus. Etomidate injection technique influences the incidence of myoclonus. This study was designed to clarify which of the two injection techniques—slow injection or priming with etomidate—is more effective in reducing myoclonus.MethodsThis prospective randomized controlled study was conducted on 189 surgical patients allocated to three study groups. Control group (Group C, n = 63) received 0.3 mg/kg etomidate (induction dose) over 20 s. Priming group (Group P, n = 63) received pretreatment with 0.03 mg/kg etomidate, followed after 1 min by an etomidate induction dose over 20 s. Slow injection group (Group S, n = 63) received etomidate (2 mg/ml) induction dose over 2 min. The patients were observed for occurrence and severity of myoclonus for 3 min from the start of injection of the induction dose.ResultsThe incidence of myoclonus in Group P (38/63 [60.3%], 95% CI: 48.0–71.5) was significantly lower than in Group C (53/63 [84.1%], 95% CI: 72.9–91.3, P = 0.003) and Group S (49/63 [77.8%], 95% CI: 66.0–86.4, P = 0.034). Myoclonus of moderate or severe grade occurred in significantly more patients in Group C (68.3%) than in Group P (36.5%, P < 0.001) and Group S (50.8%, P = 0.046), but the difference between Groups P and S was not significant (P = 0.106).ConclusionsPriming is more effective than slow injection in reducing the incidence of myoclonus, but their effects on the severity of myoclonus are comparable.

Effects of transcutaneous acupoint electrical stimulation combined with low-dose sufentanil pretreatment on the incidence and severity of etomidate-induced myoclonus: A randomized controlled trial.

Background:Myoclonus is an undesirable phenomenon that occurs after induction of general anesthesia using etomidate. Opioids such as sufentanil are considered effective pretreatment drugs for myoclonus inhibition, although high doses are required. Transcutaneous acupoint electrical stimulation (TAES), a noninvasive technique involving electrical stimulation of the skin at the acupuncture points, exhibits analgesic effects, promotes anesthetic effects, decreases the dose of anesthetic drugs, and increases endogenous opioid peptide levels. In the present study, we investigated the effects of TAES combined with low-dose sufentanil pretreatment on the incidence and severity of etomidate-induced myoclonus in patients undergoing elective hysteroscopy.Methods:In a double-blind manner, 172 patients (American Society of Anesthesiologists class I–II; age, 20–55 years) scheduled to undergo elective hysteroscopy were randomized into the following groups (n = 43 each): control (false TAES followed by saline injection after 30 min), TAES (TAES followed by saline injection after 30 minutes), sufentanil [false TAES followed by low-dose sufentanil (0.1 μg/kg) injection after 30 minutes], and sufentanil plus TAES (TAES followed by low-dose sufentanil injection after 30 minutes). In all groups, general anesthesia was induced by etomidate 0.3 mg/kg after sufentanil or saline injection. The incidence and severity of myoclonus were assessed for 2 minutes after etomidate administration. The visual analogue scale (VAS) scores for pain at 1 hour after surgery were recorded. The heart rate (HR), mean arterial pressure (MAP), and peripheral capillary oxygen saturation (SPO2) were recorded before premedication, after etomidate injection, after uterus expansion, and after recovery from anesthesia.Results:The incidence of myoclonus was highest in the control group (88.3%), followed by TAES (74.4%), sufentanil (60.4%), and TAES plus sufentanil (48.8%) groups. Thus, the incidence was significantly higher in the control and TAES groups than in the sufentanil and TAES plus sufentanil groups. Grade 3 myoclonus occurred in 30.2%, 9.3%, 11.6%, and 9.3% patients in the control, TAES, sufentanil, and TAES plus sufentanil groups, respectively, with significant differences between the control group and the other 3 groups. Furthermore, the postoperative VAS scores for pain were significantly lower in the TAES, sufentanil, and TAES plus sufentanil groups compared with those in the control group. There were no significant differences in any other parameters among groups.Conclusion:Our results suggest that TAES combined with low-dose opioids such as sufentanil can decrease the incidence and severity of etomidate-induced myoclonus.