Using dezocine to prevent etomidate-induced myoclonus: a meta-analysis of randomized trials

Dexamethasone alleviates etomidate-induced myoclonus by reversing the inhibition of excitatory amino acid transporters

Background

Etomidate can induce myoclonus with an incidence of 50 ~ 85% during anesthesia induction. Dexamethasone, as a long-acting synthetic glucocorticoid, has neuroprotective effects. However, the effects of dexamethasone on the etomidate-induced myoclonus remain uncertain.

Methods

Adult male Sprague-Dawley rats were randomly assigned to receive etomidate (1.5 mg/kg) plus dexamethasone (4 mg/kg) (etomidate plus dexamethasone group) or etomidate (1.5 mg/kg) plus the same volume of normal saline (NS) (etomidate plus NS group). The mean behavioral scores, local field potentials and muscular tension were recorded to explore the effects of dexamethasone on etomidate-induced myoclonus. Liquid chromatography coupled with tandem mass spectrometric system (LC-MS/MS), quantitative real-time polymerase chain reaction (qRT-PCR), and western blotting were applied to analyze the levels of glutamate and γ-aminobutyric acid (GABA), the mRNA and protein expression of excitatory amino acid transporters (EAATs), and plasma corticosterone levels at different time points after anesthesia.

Results

Compared with the etomidate plus NS treatment, the etomidate plus dexamethasone treatment significantly decreased the mean behavioral score at 1, 3, 4, and 5 min after administration; the peak power spectral density (PSD) (p = 0.0197) in the analysis of ripple waves; and the glutamate level (p = 0.0139) in the neocortex. However, compared with etomidate plus NS, etomidate plus dexamethasone increased the expression of the neocortical proteins of EAAT1 (p = 0.0207) and EAAT2 (p = 0.0022) and aggravated the inhibition of corticosterone at 4 h (p = 0.0019), 5 h (p = 0.0041), and 6 h (p = 0.0009) after administration.

Conclusion

Dexamethasone can attenuate the myoclonus, inhibit the glutamate accumulation, and reverse the suppression of EAATs in the neocortex induced by etomidate following myoclonus, while conversely aggravating etomidate-induced adrenal suppression.

The need to monitor emerging issues in etomidate usage: the misuse or abuse potential

Since 2011, the misuse or abuse of etomidate has gradually increased when propofol was designated a controlled drug under the Narcotics Control Act in Korea. Accordingly, the Ministry of Food and Drug Safety announced that etomidate would be under the 'Regulation on the designation of drugs that may cause concerns of misuse or abuse' rule in June 2020, which is less stringent than the Narcotics Control Act. Therefore, this review investigates potential misuse or abuse cases of etomidate to consider strengthening its management. A literature search was conducted to compare etomidate with other sedatives in their efficacy and side effects, as well as identify the adverse health outcomes, abuse cases, and analytical methods of etomidate. Etomidate has an equal or higher sedative efficacy and lower risk of adverse cardiopulmonary events than propofol. However, major adverse effects of etomidate include adrenocortical suppression and unproven associated deaths, as well as myoclonus requiring pre-treatment. Although the issue of abuse and misuse of etomidate is emerging in recent years, there are few academic reports on these issues and analytical methods in the forensic field. In order to effectively manage the misuse or abuse of etomidate, it is necessary to continuously monitor related cases with great interest and to be more intensively studied on its abuse potential.

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

OBJECTIVE

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.

INTRODUCTION

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.

INCLUSION CRITERIA

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.

METHODS

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.

RESULTS

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.

CONCLUSIONS

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.

Beyond the surface: analyzing etomidate and propofol as anesthetic agents in electroconvulsive therapy-A systematic review and meta-analysis of seizure duration outcomes

Background

Electroconvulsive therapy (ECT) is a widely used treatment for severe psychiatric disorders such as schizophrenia, depression, and mania. The procedure involves applying brief electrical stimulation to induce a seizure, and anesthesia is used to ensure sedation and muscle relaxation. Finding the right anesthetic agent with minimal side effects, especially on seizure duration, is crucial for optimal outcomes because seizure duration is an important factor in the effectiveness of ECT, but the anesthetic agents used can affect it.

Objective

This systematic review and meta-analysis aimed to pool the results of all relevant studies comparing the two induction agents, etomidate and propofol, for motor and electroencephalogram (EEG) seizure duration outcomes.

Methods

A comprehensive literature search was conducted in the PubMed, Medline, and Cochrane Library databases to identify the relevant articles. The primary outcome measures were motor and EEG seizure durations. Statistical power was ensured by performing heterogeneity, publication bias, sensitivity analysis, and subgroup analysis. Standard mean difference and 95% confidence intervals were calculated for continuous outcomes, and a random-effects model was used.

Results

A total of 16 studies were included in this meta-analysis, comprising 7 randomized control trials (RCTs), 7 crossover trials, and 2 cohorts. The overall motor seizure duration was statistically significantly longer with etomidate than with propofol. The overall result for EEG seizure duration was also longer with the use of etomidate over propofol and was statistically significant. In addition, subgrouping was performed based on the study design for both outcomes, which showed insignificant results in the cohort's subgroup for both outcomes, while the RCTs and crossover subgroups supported the overall results. Heterogeneity was assessed through subgrouping and sensitivity analysis.

Conclusion

Our meta-analysis found that etomidate is superior to propofol in terms of motor and EEG seizure duration in ECT, implying potentially better efficacy. Hence, etomidate should be considered the preferred induction agent in ECT, but larger studies are needed to further validate our findings.

Anesthesia management of patients undergoing thoracic endovascular aortic repair: A retrospective analysis of single center

Thoracic endovascular aortic repair (TEVAR) is a new alternative surgical treatment for aortic pathologies, which is more minimally invasive. The aim of current study was to summarize the single-center experience of general anesthesia for patients undergoing TEVAR. In adult patients undergoing surgery for congenital heart disease, the strategy of "fast-track" anesthesia with early extubation in theater is associated with a shorter intensive care unit (ICU) stay, and lower health-care-related costs. Fast-track anesthesia has not been assessed in patients under TEVAR. Adult patients who received general anesthesia for TEVAR in our center from January 2020 to December 2020 were included. Baseline characteristics, airway management, anesthetic techniques and major complications were collected. A total of 204 (171 male, mean age 58.1 ± 11.5 years) patients met inclusion criteria for this study. The distribution of pathologies included 29 descending thoracic aneurysms, 87 type B dissections, and 88 intramural hematoma/perforating aortic ulcer. Etomidate was the induction agent in 190 (93.1%) patients, compared with propofol in 16 (7.8%). Cisatracurium was the muscle relaxant in 201 (98.5%), compared with rocuronium in 3 (1.5%). Midazolam (benzodiazepines) was given to 124 (60.8%) patients during anesthesia induction. General anesthesia was maintained with sevoflurane in 85.3% (174) patients, dexmedetomidine in 201 (98.5%) and propofol in 204 (100%). Postoperative length of stay (LOS) in the hospital was 6.0 (5.0-7.8) days. LOS in the ICU was 23.0 (20.0-27.8) hours. Overall neurologic event rate was 2.0% (n = 4) (spinal cord ischemia 1.5% [n = 3]; stroke 0.5% [n = 1]). After matching, patients who received "fast-track" anesthesia had a shorter LOS in ICUs (21.0 [18.0-24.0] vs 24.0 [20.0-44.0] hours; P = .005), and a shorter postoperative LOS in hospital (5.0 [4.0-7.0] vs 6.0 [5.0-8.0] days; P = .001). There were no in-hospital deaths. Fast-track anesthesia is feasible and safe in patients underwent TEVAR. This management strategy is associated with shorter LOS of ICU and total postoperative hospital stays. An early extubation strategy should be implemented for hemodynamically stable patients.

Effect of etomidate and propofol on airway mechanics during induction - A prospective randomized trial

Background and Aims

Intravenous induction agents like propofol and etomidate change the airway mechanics and thus influence mask ventilation. These changes have an impact on the administration of muscle relaxant in a difficult mask ventilation scenario. The difference in dynamics of airway after administration of two different intravenous agents has been assessed in this study.

Material and Methods

After formal registry in clinical trials, patients undergoing general anesthesia were recruited and randomized into group P and E. Patients were induced with either of the intravenous agents, and mask ventilation was performed with a ventilator. After 60 s, rocuronium was administered and ventilation continued. Measurements of tidal volume, peak airway pressure, and compliance were taken from the anesthesia ventilator at different time points - induction, relaxant, and intubation.

Results

There was no statistically significant difference between the two groups with respect to demographics, airway parameters, and airway mechanics, as measured by tidal volume, peak airway pressure, and lung compliance. There was an improvement in the tidal volume and compliance following induction with propofol, with a P value of 0.007 and 0.032, respectively, obtained in within-group comparison.

Conclusion

Propofol and etomidate were comparable in airway mechanics, but compliance and tidal volumes improved with propofol, which facilitated face mask ventilation.

Median Effective Dose of an Etomidate-Propofol Mixture with Dezocine in Inhibiting the Response to Gastroscope Insertion: Gender Differences in a Randomized Controlled Study Using Dixon’s Up-and-Down Method

What Is Known and Objective. Appropriate doses of sedatives are crucial for a successful, painless upper gastrointestinal endoscopy. Hence, we conducted a randomized controlled study to explore the effects of dezocine on the median effective dose (ED50) of the etomidate-propofol (E-P) mixture in prohibiting response to gastroscope insertion in patients of different genders. Methods. Patients aged 18–65 years enrolled in the study of the American Society of Anesthesiologists (ASA) with physical status I or II undergoing elective gastroscopy were included. Patients were randomly assigned to the male normal saline group (MS group), male dezocine group (MD group), female normal saline group (FS group), and female dezocine group (FD group). All patients were anesthetized with an E-P mixture of 1 : 1. The FD and MD groups were intravenously injected (i.v.) 50 µg/kg dezocine 5 min before anesthesia, while the FS and MS groups were injected with an equal volume of normal saline 5 min before anesthesia. According to the preexperiment, the initial dose of the E-P mixture for the FD and MD groups was 0.4 and 0.3 mL/kg for the FS and MS groups. The variation proportion was set as 0.9 between dosages. Dixon’s up-and-down method was adopted to confirm the dose of the E-P mixture for the next patient, which was reduced if the insertion was performed successfully; otherwise, the dose was increased. Centered isotonic regression was employed to determine the ED50 and 90% confidence interval (CI) values of the E-P mixture in the four groups. The total amount of E-P mixture consumed was recorded as well as the adverse events of patients. Results. The ED50 and 90% CI of the MS, MD, FS, and FD groups were 0.315 (0.285–0.349), 0.206 (0.175–0.237), 0.329 (0.305–0.355), and 0.207 (0.188–0.227) mL/kg, respectively. The MD group was <MS group ( $P\le 0.001$ ), and the FD group was <FS group ( $P\le 0.001$ ); no statistical difference was observed between the MS and FS groups and MD and FD groups. Dezocine reduced the total amount of E-P mixture consumed and the overall incidence of adverse events. What Is New and Conclusion. Dezocine significantly decreased the ED50 of the E-P mixture in inhibiting the response of patients to gastroscope insertion and the occurrence rate of adverse events. Further, gender had no impact on the ED50 of the E-P mixture.

Comparison of the Effectiveness of Various Drug Interventions to Prevent Etomidate-Induced Myoclonus: A Bayesian Network Meta-Analysis

Background

Myoclonic movement is a very common but undesirable phenomenon during the induction of general anesthesia using etomidate. Such movement may cause unnecessary problems. Currently, there is an increasing number of drugs for preventing etomidate-induced myoclonus (EM). However, direct comparisons of various drugs are lacking, and this interferes with clinical decision-making. Our network meta-analysis (NMA) aimed to compare the efficacy of different drugs for the prevention of moderate-to-severe general myoclonus.

Methods

Using several biomedical databases, randomized controlled trials (RCTs) published in English from inception to August 22, 2021 were searched. Among the various interventions, we selected nine types of intervention drugs (dexmedetomidine, etomidate, lidocaine, NMDA receptor antagonist, κ opioid receptor agonist, μ opioid receptor agonist, muscle relaxant, gabapentin, and midazolam) for comparison, according to the number of studies. Bayesian NMA was performed using STATA16 and R softwares. The relative risk of EM was assessed using risk ratios (RRs) and the corresponding 95% confidence intervals (CI).

Results

A total of 31 RCTs (3209 patients) were included. NMA results showed that, compared with a placebo, etomidate (RR 4.0, 95%CI 2.1–7.8), κ opioid receptor agonist (RR 2.9, 95%CI 1.9–4.6), μ opioid receptor agonist (RR 3.1, 95%CI 2.3–4.3), NMDA receptor antagonist (RR 1.7, 95%CI 1.0–2.8), dexmedetomidine (RR 2.4, 95%CI 1.5–3.9), lidocaine (RR 2.1, 95%CI 1.2–3.9), and midazolam (RR 2.2, 95%CI 1.5–3.2) can significantly reduce the risk of EM. In contrast, the effects of muscle relaxants (RR 2.1, 95%CI 0.81–5.3) and gabapentin (RR 2.8, 95%CI 0.92–9.3) were inconclusive. Further subgroup analyses showed that preoperative low-dose etomidate, μ-opioid receptor agonist, and κ-opioid receptor agonist were significantly better than other interventions in the prevention of moderate to severe EM.

Conclusion

Preoperative use of small doses of etomidate or opioids may be the most effective way to avoid EM, especially moderate and severe EM, which makes anesthesia induction safer, more stable, and aligns better with the requirements of comfortable medicine.

Systematic Review Registration

[https://www.crd.york.ac.uk/prospero/], [CRD4202127706].

Efficacy of dezocine on preventing opioid-induced cough during general anaesthesia induction: a PRISMA-compliant systematic review and meta-analysis

OBJECTIVES

To systematically review the effects of dezocine (DZC) on the occurrence rate and severity of opioid-induced cough (OIC).

DESIGN

Systematic review and meta-analysis DATA SOURCES: PubMed, Embase, Cochrane Library, Ovid, Web of Science as well as Chinese BioMedical Literature & Retrieval System, China National Knowledge Infrastructure, Wanfang and VIP Data were searched from 1978 to 31 December 2020.

INCLUSION CRITERIA

All randomised controlled trials (RCTs) comparing DZC with placebo on the occurrence rate and severity of OIC.

DATA ANALYSIS

All data were analysed by using RevMan V.5.3. Each outcome was tested for heterogeneity, and randomised-effects or fixed-effects model was used in the presence or absence of significant heterogeneity.

RESULTS

Our search yielded 33 RCTs including 4442 patients, and 2521 patients were allocated into the DZC group and 1921 into the control group. Fentanyl was administrated in 1880 patients and sufentanil in 2562 patients during the induction of general anaesthesia. The meta-analysis demonstrated that DZC significantly reduced the occurrence rate of OIC induced by either fentanyl (8.8% vs 49.7%, OR=0.07, 95% CI 0.04 to 0.12, p<0.00001) or sufentanil (5.0% vs 41.5%, OR=0.07, 95% CI 0.04 to 0.12, p<0.00001). The meta-analysis also indicated that the occurrence rate of mild, moderate and severe OIC in the DZC group was remarkably lower than that of the control group (mild: 3.6% vs 13.6%, OR=0.19, 95% CI 0.14 to 0.25, p<0.00001; moderate: 2.0% vs 13.6%, OR=0.12, 95% CI 0.09 to 0.18, p<0.00001; severe: 1.0% vs 13.9%, OR=0.08, 95% CI 0.05 to 0.12, p<0.00001). Additionally, the current meta-analysis indicated that DZC pretreatment was not associated with increased occurrence rate of adverse effects (7.0% vs 4.2%, OR=2.34, 95% CI 0.60 to 9.14, p=0.22) except for dizziness (11.8% vs 0%, OR=8.06, 95% CI 1.40 to 46.35, p=0.02).

CONCLUSION

This meta-analysis demonstrated that DZC significantly inhibited OIC and may be used to manage OIC. More high-quality RCTs are needed to complement the safety of DZC.

PROSPERO REGISTRATION NUMBER

CRD42019141255.

Anesthetic Induction With Etomidate in Cardiac Surgical Patients: A PRISMA-Compliant Systematic Review and Meta-Analysis

OBJECTIVE

This meta-analysis aimed to systematically review the effects of etomidate (ETM) during anesthetic induction on patients undergoing cardiac surgery.

DESIGN

Systematic review and meta-analysis.

SETTING

Operating room.

PARTICIPANTS

Patients undergoing cardiac surgery.

INTERVENTIONS

ETM or control drugs.

MEASUREMENTS AND MAIN RESULTS

PubMed, Cochrane Library, OVID, and EMBASE were searched through August 31, 2020. Primary outcomes included hemodynamic profiles and stress responses. Secondary outcomes included morbidity, mortality, and postoperative recovery. For continuous/dichotomous variables, treatment effects were calculated as weighted mean difference (WMD)/odds ratio (OR) and 95% confidence interval (CI). A database search yielded 18 randomized controlled trials including 1,241 patients. The present meta-analysis demonstrated that ETM-anesthetized patients had lower heart rates (WMD, -3.31; 95% CI -5.43 to -1.19; p = 0.002), higher blood pressures (systolic blood pressure: WMD, 12.02; 95% CI 6.24 to 17.80; p < 0.0001; diastolic blood pressure: WMD, 5.23; 95% CI 2.39 to 8.08; p = 0.0003; mean arterial pressure (MAP): WMD, 8.64; 95% CI 5.85 to 11.43; p < 0.00001), less requirement for vasopressor (OR, 0.26; 95% CI 0.15 to 0.44; p < 0.00001), and more nitroglycerin usage (OR, 14.89; 95% CI 4.92 to 45.08; p < 0.00001) during anesthetic induction. Current meta-analysis also demonstrated that single-dose ETM lowered cortisol levels transiently and did not have a significant effect on endogenous norepinephrine and epinephrine levels and was not associated with increased postoperative inotrope and/or vasopressor requirement. Additionally, the meta-analysis suggested that ETM anesthesia was associated with neither increased mortality nor morbidity, except a higher incidence of transient adrenal insufficiency in ETM recipients.

CONCLUSION

The present meta-analysis suggested that single-dose ETM during anesthetic induction could be associated with more stable hemodynamics, transient and reversible lower cortisol levels, and a higher adrenal insufficiency incidence, but not worse outcomes in cardiac surgical patients.

Is dezocine effective and safe in preventing opioids-induced cough during general anaesthesia induction? A protocol for systematic review and meta-analysis

INTRODUCTION

Cough is often observed when administrating a bolus of opioids. Opioid-induced cough (OIC) is mostly transient, benign and self-limiting, but could be associated with adverse effects. Numerous pharmacological and non-pharmacological interventions have been used to manage OIC with controversial efficacy and safety. Recent studies suggested that, pretreatment of intravenous dezocine (DZC) could completely suppress OIC during anaesthesia induction. To address this knowledge lack, we will perform a systemic review and meta-analysis to evaluate the efficacy of DZC on OIC and possible complications. We provide here a protocol that will outline the methods and analyses planned for the systematic review.

METHODS

PubMed, Embase, Cochrane Library, Web of Science as well as Chinese BioMedical Literature & Retrieval System (SinoMed), China National Knowledge Infrastructure, Wanfang Data and VIP Data will be searched from 1978 to 31 December 2019 to identify all randomised controlled trials comparing DZC with placebo on the incidence and severity of OIC. Primary outcomes of interest include the incidence and severity of OIC. Secondary outcomes of interest include possible complications or adverse effects of DZC. Two authors will independently extract relevant variables and outcome data. For continuous variables, treatment effects will be calculated as weighted mean difference and 95% CI. For dichotomous data, treatment effects will be calculated as OR and 95% CI. Each outcome will be tested for heterogeneity, and randomised-effects or fixed-effects model will be used in the presence or absence of significant heterogeneity. Sensitivity analyses will be done by examining the influence of statistical model and individual trial(s) on estimated treatment effects. Publication bias will be explored through visual inspection of funnel plots of the outcomes. Statistical significance will be defined as p<0.05.

ETHICS AND DISSEMINATION

This study is a protocol of meta-analysis of previously published literatures, ethical approval was not necessary according to the Ethical Committee of Fuwai Hospital. The study will be submitted to a peer-reviewed journal and disseminated via research presentations.

PROSPERO REGISTRATION NUMBER

CRD42019141255.

Dezocine regulates the malignant potential and aerobic glycolysis of liver cancer targeting Akt1/GSK-3β pathway

Background

Due to the “ceiling effect” of respiratory depression and the non-addictiveness, the consumption of dezocine is increasing quickly in the cancer surgery perioperative period for security and comfort reasons in China. Former studies find dezocine inhibits the norepinephrine transporters (NET) and serotonin transporters (SERT) and sigma-1opioid receptors. Given the complexity of the molecular mechanism, the effect of dezocine on tumor cells need to be studied. In this study, we investigated the effect of dezocine on HepG2 and Hep 3B liver cancer cell lines growth and glycolysis, and the molecular mechanisms behind.

Methods

HepG2 and Hep 3B cells viability and migration were measured by CCK8, Wound healing and transwell assay, Extracellular acidification rate (ECAR) was used to index the aerobic glycolysis of liver cancer cells and western blot analysis showed protein expression levels in the cells. SC79, an agonist of Akt, and the siRNA silence of Akt1 aimed to regulate Akt1 activity and expression in the reverse experiments.

Results

Dezocine played opposite roles in HepG2 and Hep 3B cells viability and migration in a concentration-dependent manner (P<0.01). Dezocine has diverse effects on aerobic glycolysis and adjusts the serine/threonine kinase 1 (Akt1)-glycogen synthase kinase-3β (GSK-3β) pathway. The effects of SC79 and the siRNA silence of Akt1 could reverse the effects of dezocine on HepG2 and Hep 3B cells.

Conclusions

As an analgesic drug widely used in clinical practice, dezocine play reversed roles on HepG2 and Hep 3B cells viability and migration targeting Akt1/GSK-3β pathway then the glycolysis in a concentration-dependent manner.

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.

Effect of butorphanol on etomidate-induced myoclonus: a systematic review and meta-analysis

Objective: To evaluate the effect of butorphanol on the prevention of myoclonus induced by etomidate.

Materials and methods: We searched the PubMed, Embase, Cochrane Library, and China National Knowledge Infrastructure databases to collect relevant randomized controlled trials (RCTs) evaluating the effect of butorphanol on etomidate-induced myoclonus in January 2019 without any language restrictions. The primary outcome was the incidence of etomidate-induced myoclonus. Secondary outcomes included the incidence of myoclonus at various degrees and the incidence of adverse effects. Risk ratios (RRs) were calculated for binary outcomes. All statistical analysis were performed by using RevMan 5.3 software.

Results: We identified 6 RCTs involving a total of 608 patients who reported the incidence of etomidate-induced myoclonus. In pooled analyses, the incidence of etomidate-induced myoclonus in the butorphanol group was significantly lower than that in the control group (RR =0.15, 95% CI [0.10, 0.22], P<0.00001). Subgroup analyses showed that butorphanol significantly decreased the numbers of patients with mild myoclonus (RR =0.41, 95% CI [0.25, 0.68], P=0.0005), moderate myoclonus (RR =0.18, 95% CI [0.09, 0.34], P<0.00001), and severe myoclonus (RR =0.04, 95% CI [0.01, 0.10], P<0.00001). Additionally, butorphanol did not increase the incidence of postoperative nausea/vomiting (RR =3.0, 95% CI [0.32, 28.42], P=0.34) or dizziness (RR =6.79, 95% CI [0.84, 54.84], P=0.07) associated with etomidate.

Conclusion: Our findings suggest that butorphanol can effectively prevent the incidence of etomidate-induced myoclonus and alleviate the intensity of etomidate-induced myoclonus, without inducing postoperative nausea/vomiting and dizziness.

Butorphanol effectively prevents etomidate-induced myoclonus: a pooled analysis of 788 patients

OBJECTIVE

To evaluate the efficacy of pre-injection of butorphanol on etomidate-induced myoclonus during anesthesia induction.

METHODS

Randomized controlled trials (RCTs) of the ability of butorphanol to prevent etomidate-induced myoclonus were collected by searching PubMed, Cochrane Library, CNKI, and WanFang databases, from the day of database establishment until May 2017. The literature was screened independently by two evaluators, and the data were then extracted and independently evaluated. Finally, meta-analysis was performed by using RevMan 5.2 software.

RESULTS

Eight RCTs were analyzed. The results of meta-analysis showed that: 1. compared with the control group, butorphanol was effective in preventing etomidate-induced myoclonus [RR = 0.15, 95% CI: 0.11, 0.21]; 2. butorphanol was effective in preventing mild, moderate, and severe etomidate-induced myoclonus [RR = 0.40, 95% CI: 0.25, 0.63; RR = 0.15, 95% CI: 0.08, 0.27; and RR = 0.04, 95% CI: 0.01, 0.09]; 3. butorphanol did not increase the incidence of dizziness and nausea associated with etomidate.

CONCLUSIONS

Butorphanol could reduce the incidence and degree of etomidate-induced myoclonus. Notably, it did not increase the incidence of dizziness and nausea associated with etomidate.

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

Objective

One 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 methods

The 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.

Results

A 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.

Conclusion

Pretreatment 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.