Etomidate Injection Research Articles

The effect of midazolam co-induction on cardiorespiratory variables, myoclonus and etomidate dose requirements in healthy cats.

To evaluate dose requirements of etomidate for endotracheal intubation, with or without midazolam co-induction, and to describe induction quality and associated cardiorespiratory variables in healthy cats. Randomized prospective experimental study. A group of 24 adult neutered cats (17 females, seven males). Cats were premedicated with intramuscular butorphanol (0.4 mg kg-1) and alfaxalone (2 mg kg-1), and anesthesia was induced with etomidate following midazolam (0.3 mg kg-1) or physiologic saline (0.06 mL kg-1) intravenously. Heart rate, respiratory rate (fR) and arterial blood pressure were measured following premedication, at co-induction, after etomidate administration, and after orotracheal intubation and compared using repeated-measures anova. Pre- and post-etomidate blood samples were assessed for the presence of hemolysis. Etomidate dose requirements and prevalence of myoclonus were compared with Wilcoxon signed ranks test and Fisher's test. Values of p < 0.05 were considered significant. Mean ± standard deviation etomidate doses required for orotracheal intubation were 0.84 ± 0.26 and 1.39 ± 0.33 mg kg-1 for midazolam and saline co-induction, respectively (p= 0.001). The presence of myoclonus at sedated baseline, co-induction and etomidate was 6/12, 8/12 and 9/12 in the saline group, respectively, and 10/12, 2/12 and 0/12 in the midazolam group. The prevalence of myoclonus was lower in the midazolam group after co-induction and etomidate injection (p= 0.036 and p < 0.001, respectively). Cardiorespiratory variables did not differ between groups at any time point. Compared with baseline, fR decreased in both groups after etomidate injection and intubation. Hemolysis was observed in all post-etomidate plasma samples. Etomidate, with or without midazolam co-induction, provides acceptable cardiovascular function in premedicated healthy cats. Midazolam reduces etomidate requirements for orotracheal intubation and improves induction quality in cats premedicated with intramuscular butorphanol-alfaxalone.

Unconscious classification of quantitative electroencephalogram features from propofol versus propofol combined with etomidate anesthesia using one-dimensional convolutional neural network.

Establishing a convolutional neural network model for the recognition of characteristic raw electroencephalogram (EEG) signals is crucial for monitoring consciousness levels and guiding anesthetic drug administration. This trial was conducted from December 2023 to March 2024. A total of 40 surgery patients were randomly divided into either a propofol group (1% propofol injection, 10 mL: 100 mg) (P group) or a propofol-etomidate combination group (1% propofol injection, 10 mL: 100 mg, and 0.2% etomidate injection, 10 mL: 20 mg, mixed at a 2:1 volume ratio) (EP group). In the P group, target-controlled infusion (TCI) was employed for sedation induction, with an initial effect site concentration set at 5-6 μg/mL. The EP group received an intravenous push with a dosage of 0.2 mL/kg. Six consciousness-related EEG features were extracted from both groups and analyzed using four prediction models: support vector machine (SVM), Gaussian Naive Bayes (GNB), artificial neural network (ANN), and one-dimensional convolutional neural network (1D CNN). The performance of the models was evaluated based on accuracy, precision, recall, and F1-score. The power spectral density (94%) and alpha/beta ratio (72%) demonstrated higher accuracy as indicators for assessing consciousness. The classification accuracy of the 1D CNN model for anesthesia-induced unconsciousness (97%) surpassed that of the SVM (83%), GNB (81%), and ANN (83%) models, with a significance level of p < 0.05. Furthermore, the mean and mean difference ± standard error of the primary power values for the EP and P groups during the induced period were as follows: delta (23.85 and 16.79, 7.055 ± 0.817, p < 0.001), theta (10.74 and 8.743, 1.995 ± 0.7045, p < 0.02), and total power (24.31 and 19.72, 4.588 ± 0.7107, p < 0.001). Large slow-wave oscillations, power spectral density, and the alpha/beta ratio are effective indicators of changes in consciousness during intravenous anesthesia with a propofol-etomidate combination. These indicators can aid anesthesiologists in evaluating the depth of anesthesia and adjusting dosages accordingly. The 1D CNN model, which incorporates consciousness-related EEG features, represents a promising tool for assessing the depth of anesthesia. https://www.chictr.org.cn/index.html.

Comparison of the effect of lidocaine and its combination with melatonin and the Valsalva maneuver on etomidate induced injection pain

Background &amp; Objective: Etomidate is commonly used in anesthesia practice because of its rapid recovery time, low incidence of apnea, and lower incidence of allergic reactions; but pain upon injection is one of the unfavorable complications of this drug, which can cause both physical and mental discomfort to the patients. It is imperative to use appropriate means to lower the pain at the injection site of etomidate in patients undergoing anesthesia. We conducted this study to compare the effects of lidocaine, lidocaine and the Valsalva maneuver, with a combination of lidocaine, melatonin and the Valsalva maneuver on decreasing the pain of etomidate injection. Methodology: This clinical trial enrolled 135 patients. The patients were allocated into 3 groups, with one group receiving lidocaine (Group 1), the second group receiving lidocaine and the Valsalva maneuver (Group 2), and the last group receiving a combination of lidocaine, melatonin and the Valsalva maneuver. The pain resulting from injecting etomidate was evaluated based upon the Visual Analog Scale (VAS) score (with 1 being no pain and 10 the most severe imaginable pain). Data were compared and analyzed using proper statistical tests using SPSS version 23. Results: The results of this study showed that the overall pain score in all of the groups after injection of etomidate did not show any significant difference. The mean VAS score in Group 1 was 0.27 ± 0.88, in Group 2 it was 0.16 ± 0.63, and in Group 3 0.04 ± 0.2. However, the difference between the groups was statistically not significant (P = 0.32). Conclusion: The current study shows that the pain on injection of etomidate in the three groups of the study was reduced in a similar fashion; however, in the group which combined lidocaine, melatonin and the Valsalva maneuver, pain was the lowest, but the overall differences in score in the three groups were statistically not different. Keywords: Etomidate, lidocaine, melatonin, Valsalva maneuver. Citation: Nazemroaya B, Poudeh ND. Comparison of the effect of lidocaine and its combination with melatonin and the Valsalva maneuver on etomidate induced injection pain. Anaesth. pain intensive care 2024;28(5):842−849; DOI: 10.35975/apic.v28i5.2279 Received: July 27, 2024; Reviewed: September 04, 2024; Accepted: September 09, 2024

Evaluation of the efficacy of the valsalva maneuver and fentanyl administration for attenuating etomidate injection pain: A double-blind clinical trial

Objective: Etomidate is mentioned as one of the rapid intravenous anesthetic drugs whose unique characteristics include hemodynamic stability, negligible respiratory depression, and brain protection. The most common complication of etomidate is intravenous pain during injection. The purpose of this study was to compare the effectiveness of the Valsalva maneuver and fentanyl in reducing the pain caused by etomidate injection for anesthesia induction. Methods: This clinical trial was performed on 96 patients at Alzahra hospital, affiliated with the Isfahan University of Medical Sciences, from January to June 2021. Patients were divided into two groups of 48 people: the Valsalvamaneuver group (group 1) and the fentanyl group (group 2). Blood pressure, heart rate (HR), oxygen saturation, and pain of etomidate injection using the withdrawal response score were graded on a four-point scale (no pain=zero, mild pain=1, average pain=2, and severe pain=3). The collected information was entered into SPSS software version 24. Then, the pain score in the two groups was compared using the chi-square test. The significance level in the present study was P&lt;0.05. Results: The mean HR (P=0.07), mean arterial pressure (MAP) (P=0.33), systolic pressure (P=0.90), diastolic pressure (P=0.67), and oxygen saturation level (P=0.27) at different times between the two groups showed no significant difference (P&gt;0.05). However, during the etomidate injection, the HR increased and after the injection, the HR decreased in both groups (P=0.042). The two groups had no significant difference regarding pain frequency. Conclusion: There was no difference in the effect of the Valsalva maneuver and fentanyl on reducing the pain caused by etomidate injection.

Effect of Pretreatment with a Small Dose of Esketamine on Myoclonus Induced by Etomidate: A Randomized Controlled Trial.

Etomidate has been observed to precipitate myoclonus in patients undergoing induction of general anaesthesia. This study was designed to investigate the effect of pretreatment with a small dose of esketamine on the incidence of myoclonus induced by etomidate. One hundred adult patients, who were scheduled to undergo selective operations with general anesthesia, were randomly divided into two groups, with one group receiving esketamine (Group E) and the other receiving normal saline (Group C). The group receiving esketamine (Group E) was administered an injection of 0.15 mg/kg of esketamine, while the control group (Group C) was given an equivalent volume of normal saline two minutes before the administration of 0.3 mg/kg of etomidate. The primary objective was to determine the incidence of etomidate-induced myoclonus. Secondary endpoints included the severity of etomidate-induced myoclonus and changes in haemodynamic variables at various time intervals. Additionally, the incidence of adverse effects such as dizziness, bradycardia, hypotension and hallucination were recorded from the administration of esketamine or normal saline to the injection of etomidate. The incidence of myoclonus was significantly lower in Group E (20%) than in Group C (62%). Compared with the control group, the esketamine group also experienced a reduction in the moderate and severe of myoclonus. However, there was no statistically significant difference between the two groups for mild etomidate-induced myoclonus. The haemodynamic data (mean arterial pressure and heart rate) showed no statistically significant differences between two groups at the three time points. The incidence of dizziness, bradycardia, hypotension and hallucination was similar in both groups. Pretreatment with 0.15 mg/kg esketamine prior to anaesthesia induction with etomidate was observed to markedly reduce the incidence and severity of myoclonus, while having no effect on mild etomidate-induced myoclonus and maintaining a stable haemodynamic status.

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.

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.

Comparing intensity of pain due to intravenous injection of sodium thiopental, propofol, diazepam, and etomidate during induction of general anesthesia.

The aim of the present study was to compare the pain intensity due to intravenous injection of sodium thiopental, propofol, diazepam, and etomidate during the induction of general anesthesia. This was a non-controlled quasi-experimental double-blinded study performed on eligible patients referred to the operating room of Shahid Beheshti Hospital in Yasouj. A total of 200 patients were randomly selected by convenience sampling and based on a table of random numbers generated on a computer. They were then randomly divided into four intervention groups based on random blocks (sodium thiopental, propofol, etomidate, and diazepam). Finally, the collected data were analyzed using descriptive as well as analytical statistical tests such as Chi-square, analysis of covariance (ANCOVA), and Bonferroni post hoc test were analyzed in SPSS ver. 24. The results of the present study showed that the diazepam group experienced the highest pain intensity (8.42) compared to other groups, which was statistically significant (P = 0.001). Also, the sodium thiopental group experienced the highest pain (6.92) after the diazepam group, which was also statistically significant as compared to the other remaining two groups (P = 0.001). Propofol and etomidate groups experienced the lowest pain intensity (3.30 and 3.26, respectively). The present study revealed that the use of diazepam and sodium thiopental as anesthetic drugs was generally associated with greater pain intensity during injection and less hemodynamic stability. The results of the present study indicated that propofol and etomidate are preferred over diazepam and sodium thiopental in abdominal and gastrointestinal surgeries, considering their less pain intensity and fewer hemodynamic changes.

A comparison of pretreatment with lignocaine versus dexmedetomidine in prevention of etomidate induced myoclonus- A randomised comparative trial

Etomidate is a short-acting non-barbiturate intravenous anesthetic with rapid induction and rapid awakening. It is frequently utilized in clinical practice, especially for patients with an unstable cardiovascular system, due to its minimal influence on hemodynamics and respiratory depression. However, Etomidate might cause side effects during anaesthetic induction, such as injection discomfort, phlebitis, hemolysis, and myoclonus. This study was, therefore, conducted in order to compare the pre-treatment with lignocaine versus dexmedetomidine in deterrence of myoclonus resulting from Etomidate.60 patients were allocated randomly into two study groups. Each group comprising 30 patients. Patients in GroupI received injection Lignocaine (1 mg/kg)and Group II received injection Dexmedetomidine (0.5μg/kg) in 10 ml of normal saline over 10 min followed by Etomidate injection (0.3 mg/kg) over 30 s. Patients were observed for 2 minutes for occurrence of myoclonus and the intensity and time of occurrence was noted by a person blinded to the drug used.In our study, 90% patients were myoclonus grade zero, followed by 6.7%, 3.3% and no one of myoclonus grade one, two and three in dexmedetomidine group at 1 min. 60.0%, 10.0%, 13.3% and 16.7% patients had grade zero, one, two, three of myoclonus respectively in lignocaine group at 1 min. 80.0% patients were myoclonus grade zero, followed by 13.3%, 3.3%, 3.3% of patients had myoclonus grade one, two, three respectively in dexmedetomidine group at 2mins. 53.3%, 10.0%, 16.7%, 20.0% patients were myoclonus grade zero, one, two and three respectively in lignocaine group at 2mins. On the whole 46.7% patients in lignocaine group developed Myoclonus; but 20.0% in dexmedetomidine group shows the myoclonus.We conclude that the prevalence of Etomidate-induced myoclonus was significantly decreased in patients who were pre-treated with dexmedetomidine in comparison with lignocaine.

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.

Comparison of Pain on Injection of Etomidate versus Etomidate-Lipuro in Patients Undergoing Elective Orthopedic Surgery: A Double-Blind Randomized Clinical Trial

Background: Etomidate is an efficient general anesthetic associated with injection pain. Etomidate-Lipuro is its lipid emulsion, suggested to have less adverse effects. We aim to compare the injection pain of etomidate vs. etomidate-lipuro. Methods: This double-blind randomized clinical trial investigated 46 hands (23 patients) undergoing elective orthopedic surgery referring to our hospital from May to September 2017. For each patient, intravenous (IV) access was put on both hands, on one of which 2 ml of etomidate (drug A) and on the other one, 2 ml of etomidate-lipuro (drug B) were infused simultaneously. Pain scores were compared between drug types by the Wilcoxon signed-rank test using the SPSS software. Results: Among 23 patients included in the study, 8 (34.8%) were female. Mean ± standard deviation (SD) of the patients’ age was 40.52 ± 13.07 years (range: 22-60 years). The type of drug injected to the right hand was drug A in 14 hands (60.9%) and drug B in 9 hands (39.1%). Mean ± SD of pain scores was 3.57 ± 3.30 for drug A (P &lt; 0.001). The hand side (left/right) showed no significant effect on the pain scores (P = 0.535). Conclusion: This randomized clinical trial used each person as his/her own control (left/right hands). Given the results, etomidatelipuro showed significant superiority over etomidate regarding injection pain. In fact, most patients felt no pain, which suggests etomidate-Lipuro as an appropriate sedative.

Correlation between pain rating index and end-tidal sevoflurane concentration during sevoflurane anesthesia.

ObjectiveTo investigate the correlation between the pain rating index (PRi), which is an index derived from processed electroencephalography signals, and the end-tidal sevoflurane concentration (ETsevo).MethodsThis study involved 50 adults with a body mass index of 18 to 25 kg/m2 who were undergoing elective surgery under general anesthesia. Thyrocricocentesis was performed with 2.5 mL of 2% tetracaine for endotracheal surface anesthesia, and intravenous injections of midazolam, etomidate, and rocuronium were then administered. The patients’ tracheas were intubated and their ventilatory rate was adjusted to maintain the partial pressure of end-tidal carbon dioxide at 30 to 35 mmHg. Anesthesia was maintained with sevoflurane. The ETsevo was adjusted to maintain anesthesia at 0.6, 0.8, 1.0, and 1.2 minimum alveolar concentration for 15 minutes each, and the PRi, mean arterial pressure (MAP), and heart rate were recorded at each concentration.ResultsA negative correlation was found between the PRi and ETsevo (−0.882) and between the MAP and ETsevo (−0.571). A low positive correlation was found between the PRi and MAP (0.484).ConclusionsThe PRi showed a high negative correlation with the ETsevo. Therefore, the PRi can be used to guide the depth regulation of sevoflurane anesthesia.Clinical trial registration number: ChiCTR-IPR-17012092

Etomidate anesthesia in chicks: Effect of xylazine

The current study aimed to evaluate the etomidate anesthetic action, its toxicity profile and safety alone and to determine the benefit of xylazine coadministration to enhance its anesthetic duration, efficacy and to reach a state of balanced anesthesia in chicks. By using the up-and-down technique, it was found that the hypnotic Median Effective Dose (ED50) of the etomidate was 4.30 mg/kg, IM, whereas the acute Median Toxic Dose (TD50) was 17.90 mg/kg, IM in the chicks. In response, the calculated Therapeutic Index (TI) and Standard Safety Margin (SSM) indicate that the etomidate has a wide safety margin. Etomidate injection at 4, 8 and 16 mg/kg, IM yields a significant dose-response and dependent hypnosis in the chicks by evaluating the onset of the righting reflex loss, its period and regaining from it. The combination composed of etomidate and xylazine at 5 mg/kg, IM for each, reduced the onset of hypnosis and significantly distended its period besides a significant rise of the recovery time when compared with the group receiving etomidate alone. At the same time, this coadministered drugs elicited a significant raise in analgesic efficacy. Concerning plasma glucose, Alanine Transaminase (ALT) and Aspartate Transaminase (AST) concentrations, neither etomidate nor etomidate plus xylazine differ significantly from the control group. The results of this study propose the likelihood of using etomidate as an anesthetic agent for short surgical trials in the chickens that can be more effective by using xylazine to yield balanced anesthesia without causing significant side effects.

A comparison of fentanyl and dexamethasone pretreatment for prevention of etomidate induced myoclonus, a randomized double blind placebo controlled study

Etomidate is used for induction of anaesthesia in haemodynamically unstable patients but its use is associated with undesirable side effects like myoclonus, incidence of which is 50-80%. This prospective, randomized, placebo controlled study is to compare the effect of dexamethasone and fentanyl for prevention of etomidate induced myoclonus. Ninety adult patients were randomly assigned into three groups to receive Dexamethasone (group D), Fentanyl (group F) and placebo (group P) five min before injection etomidate 0.3mg/kg IV. The patients were assessed for myoclonus using a four point intensity scoring system over a period of 5 min. ANOVA and chi square test were used for statistical analysis and P&amp;#60;0.05 was considered as statistically significant. The incidence of myoclonus was significantly reduced in groups D and F compared with group P (p value 0.001).The incidence of pain associated with Etomidate induced myoclonus also was significantly reduced in groups D and F compared to group P (p value 0.001). Dexamethasone significantly reduces the incidence of myoclonus as compared to placebo. It also significantly reduces the pain associated with Etomidate injection. However its efficacy to reduce pain and myoclonus as compared to Fentanyl is much less.

Hippocampal microglial activation triggers a neurotoxic-specific astrocyte response and mediates etomidate-induced long-term synaptic inhibition

BackgroundAccumulating evidence has highlighted the importance of microglial and astrocyte responses in the pathological development of postoperative cognitive dysfunction (POCD). However, the mechanisms involved are not well understood.MethodsA perioperative neurocognitive disorders (PND) mouse model was generated by administering etomidate, and cognitive function was assessed using the Morris water maze and novel object recognition tests. Excitatory and inhibitory postsynaptic currents were recorded to analyze neuronal activity. In addition, microglia and astrocytes were isolated by magnetic-activated cell sorting, and genes that were activated in these cells were identified using quantitative polymerase chain reaction.ResultsWe observed dramatic cognitive impairment at 1 and 3 weeks after etomidate was administered to 18 month-old mice. Microglia and astrocytes isolated from the hippocampus showed significant microglial activation during the early pathological stage (i.e., 1 week after etomidate injection) and an A1-specific astrocyte response during the late pathological stage (i.e., 3 weeks after etomidate injection). Furthermore, when microglia were eliminated before etomidate was injected, the A1-specific astrocyte activation response was significantly reduced, and cognitive function improved. However, when microglia were eliminated after etomidate application, astrocyte activation and cognitive function were not significantly altered. In addition, activating microglia immediately after a sedative dose of etomidate was injected markedly increased A1-specific astrocyte activation and cognitive dysfunction.ConclusionsA1-specific astrocyte activation is triggered by activated microglia during the initial pathological stage of PND and induces long-term synaptic inhibition and cognitive deficiencies. These results improve our understanding of how PND develops and may suggest therapeutic targets.

Phospholipase C-related inactive protein type-1 deficiency affects anesthetic electroencephalogram activity induced by propofol and etomidate in mice.

The general anesthetics propofol and etomidate mainly exert their anesthetic actions via GABA A receptor (GABAA-R). The GABAA-R activity is influenced by phospholipase C-related inactive protein type-1 (PRIP-1), which is related to trafficking and subcellular localization of GABAA-R. PRIP-1 deficiency attenuates the behavioral reactions to propofol but not etomidate. However, the effect of these anesthetics and of PRIP-1 deficiency on brain activity of CNS are still unclear. In this study, we examined the effects of propofol and etomidate on the electroencephalogram (EEG). The cortical EEG activity was recorded in wild-type (WT) and PRIP-1 knockout (PRIP-1 KO) mice. All recorded EEG data were offline analyzed, and the power spectral density and 95% spectral edge frequency of EEG signals were compared between genotypes before and after injections of anesthetics. PRIP-1 deficiency induced increases in EEG absolute powers, but did not markedly change the relative spectral powers during waking and sleep states in the absence of anesthesia. Propofol administration induced increases in low-frequency relative EEG activity and decreases in SEF95 values in WT but not in PRIP-1 KO mice. Following etomidate injection, low-frequency EEG power was increased in both genotype groups. At high frequency, the relative power in PRIP-1 KO mice was smaller than that in WT mice. The lack of PRIP-1 disrupted the EEG power distribution, but did not affect the depth of anesthesia after etomidate administration. Our analyses suggest that PRIP-1 is differentially involved in anesthetic EEG activity with the regulation of GABAA-R activity.

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.

The pain reduction efficacy of granisetron, dexmedetomidine and lidocaine after etomidate injection for surgery under general anaesthesia

Introduction: Pain on injection of anaesthetics is significant for patients' dissatisfaction. The present study aimed to compare the efficacy of granisetron, dexmedetomidine and lidocaine on the reduction of etomidate injection pain. Materials and Methods: A clinical trial was performed on 132 patients aged 18–50 years undergoing elective surgery under general anaesthesia. Two cannulas were inserted into the veins on the dorsum of both hands, and arterial drainage of both was occluded. The patients were randomised into three groups and injected with 6 mg granisetron, 40 mg lidocaine and 5 mcg dexmedetomidine, respectively, into one arm, while injecting normal saline into the other arm. Two minutes later, the tourniquet was released in each group, and 2 mg etomidate was injected into each arm. Participants were asked to rate their pain using the visual analogue scale for each arm on injection, as well as 5 min after injection. Results: A significant difference was found in pain scores of etomidate injection in the three groups of dexmedetomidine, lidocaine and granisetron. Moreover, the pain reduction effect was lower both immediately and at 5 min after injection in dexmedetomidine group than other groups (P = 0.03). In addition, the mean of pain score was lower in lidocaine group than granisetron group (P = 0.01). Nevertheless, the trend of haemodynamic parameters was not significant and different among studied groups (P > 0.05). Conclusion: Dexmedetomidine seems to have been more efficient than the others in reducing etomidate injection pain. However, the adverse effect of the three interventions was not different, and the haemodynamic parameters were stable during anaesthesia.

Etomidate affects the anti-oxidant pathway to protect retinal ganglion cells after optic nerve transection.

Our previous studies revealed that etomidate, a non-barbiturate intravenous anesthetic agent, has protective effects on retinal ganglion cells within 7 days after optic nerve transection. Whether this process is related to anti-oxidative stress is not clear. To reveal its mechanism, we established the optic nerve transection injury model by transecting 1 mm behind the left eyeball of adult male Sprague-Dawley rats. The rats received an intraperitoneal injection of etomidate (4 mg/kg) once per day for 7 days. The results showed that etomidate significantly enhanced the number of retinal ganglion cells retrogradely labeled with Fluorogold at 7 days after optic nerve transection. Etomidate also significantly reduced the levels of nitric oxide and malonaldehyde in the retina and increased the level of glutathione at 12 hours after optic nerve transection. Thus, etomidate can protect retinal ganglion cells after optic nerve transection in adult rats by activating an anti-oxidative stress response. The study was approved by the Animal Ethics Committee at Air Force Medical University, China (approval No. 20180305) on March 5, 2018.

Mechanisms of Etomidate-Mediated Decrease of Spontaneous Spike Activity of Mouse Cerebellar Purkinje Cells in vivo

Etomidate is an imidazole, nonbarbiturate hypnotic agent that is increasingly used in procedural sedation. However, the effects of etomidate on the spontaneous activity of cerebellar Purkinje cells (PCs) in living mouse have not been fully understood. In this study, we investigated the effects of etomidate on the spontaneous simple spike (SS) activity of PCs in urethane-anesthetized mice by cell-attached recording and pharmacological methods. Cerebellar surface application of etomidate (50 μmol\\L) reduced the SS firing rate in a concentration-dependent manner (IC50: 43.4 µmol\\L). Application of either a γ-aminobutyric acid type A (GABA_A) receptor antagonist, SR95531 (20 μmol\\L) or a glycine receptor antagonist strychnine (10 μmol\\L) significantly attenuated but not abolished the etomidate-induced decrease in PC SS firing rate. However, co-application of SR95531 (20 μmol\\L) and strychnine (10 μmol\\L) abolished the etomidate-induced decrease in PC SS firing rate. Moreover, intraperitoneal injection of etomidate (3 mg/kg body weight) also induced a significant depression in PC SS firing rate, which was blocked by the co-application of SR95531 and strychnine on the cerebellar surface. These results indicate that both GABA_A and glycine receptors are involved in the etomidate-induced decrease in PC SS firing rate in vivo in mice.