OBJECTIVES: To establish a method for the simultaneous quantitative analysis of etomidate and its metabolite etomidate acid in blood, and to discuss its application value in actual cases. METHODS: Acetonitrile precipitate protein method was used, and C₁₈ column was selected. Gradient elution was performed with acetonitrile and 5 mmol/L ammonium acetate within 6 min. Electrospray ionization source in positive ion mode was used. The internal standard etomidate acid-d₅ was obtained by etomidate-d₅ alkaline hydrolysis reaction. Ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) was used for quantitative analysis. The methodological verification was conducted. RESULTS: Etomidate and etomidate acid in blood showed good linear relationship in the quantitative linear range (r>0.999), with the lower limit of quantification was 2.5 ng/mL and 7.5 ng/mL, respectively. The accuracy, precision, recovery rate, and matrix effect of the method met the professional verification standards. The practical application results showed that etomidate and etomidate acid could be detected in the blood of the abusers, and their mass concentrations ranged from 17.24 to 379.93 ng/mL. CONCLUSIONS The method established in this study can simultaneously quantify etomidate and etomidate acid in blood, which is simple and convenient to operate with accuracy. It can meet the detection needs of actual cases and provide technical support for law enforcement to crack down on etomidate abuse.
Chromatography, High Pressure Liquid/methods* ; Chromatography, Liquid ; Etomidate ; Tandem Mass Spectrometry/methods* ; Liquid Chromatography-Mass Spectrometry ; Acetonitriles

OBJECTIVES: To explore the effect of etomidate on the neuronal activity of ventral thalamic reuniens nucleus and the underlying mechanisms. METHODS: Whole-cell patch clamp method was used to explore the effect of etomidate on the activity of ventral thalamic reuniens neurons in the acute brain slices obtained from 4-5 weeks old C57BL/6J mice. The electrophysiological characteristics of ventral thalamic reuniens neurons were recorded in the current clamp mode, and then the effects of etomidate (0.5, 2.0, 8.0 μmol/L etomidate groups) and intralipid (intralipid group) on the discharge frequency and membrane potential of ventral thalamic reuniens neurons were recorded. During the experiment, the ventral thalamic reuniens neuron firing rates (RNFRs) were recorded as F RESULTS: In the intralipid group, there was no significant difference among the F CONCLUSIONS Etomidate can inhibit the activity of ventral thalamic reuniens neurons in concentration-dependent manner, and which is reversible. Etomidate with sub-anesthetic concentration inhibits the activity of ventral thalamic reuniens neurons via targeting the GABA
Animals ; Etomidate/pharmacology* ; Mice ; Mice, Inbred C57BL ; Neurons ; Patch-Clamp Techniques ; Receptors, GABA-A

OBJECTIVE: To investigate the effects of etomidate on electrophysiological properties and nicotinic acetylcholine receptors (nAChRs) of ventral horn neurons in the spinal cord. METHODS: The spinal cord containing lumbosacral enlargement was isolated from 19 neonatal SD rats aged 7-12 days. The spinal cord were sliced and digested with papain (0.18 g/30 mL artificial cerebrospinal fluid) and incubated for 40 min. At the ventral horn, acute mechanical separation of neurons was performed with fire-polished Pasteur pipettes, and perforated patch-clamp recordings combined with pharmacological methods were employed on the adherent healthy neurons. In current-clamp mode, the spontaneous action potential (AP) of the ventral horn neurons in the spinal cord was recorded. The effects of pretreatment with different concentrations of etomidate on AP recorded in the ventral horn neurons were examined. In the voltage-clamp mode, nicotine was applied to induce inward currents in the ventral horn neurons, and the effect of pretreatment with etomidate on the inward currents induced by nicotine were examined with different etomidate concentrations, different holding potentials and different use time. RESULTS: The isolated ventral horn neurons were in good condition with large diverse somata and intact processes. The isolated spinal ventral horn neurons (=21) had spontaneous action potentials, and were continuously perfused for 2 min with 0.3, 3.0 and 30.0 μmol/L etomidate. Compared with those before administration, the AP amplitude, spike potential amplitude and overshoot were concentration-dependently suppressed ( < 0.01), and spontaneous discharge frequency was obviously reduced ( < 0.01, =12). The APs of the other 9 neurons were completely abolished by etomidate at 3.0 or 30 μmol/L. At the same holding potential (VH=-70 mV), pretreatment with 0.3, 3.0 or 30.0 μmol/L etomidate for 2 min concentration-dependently suppressed the current amplitude induced by 0.4 mmol/L nicotine ( < 0.01, =7). At the holding potentials of - 30, - 50, and - 70 mV, pretreatment with 30.0 μmol/L etomidate for 2 min voltage-dependently suppressed the current amplitude induced by 0.4 mmol/L nicotine ( < 0.01, =6 for each holding potential). During the 6 min of 30.0 μmol/L etomidate pretreatment, the clamped cells were exposed to 0.4 mmol/L nicotine for 4 times at 0, 2, 4, and 6 min (each exposure time was 2 s), and the nicotinic current amplitude decreased gradually as the number of exposures increased. But at the same concentration, two nicotine exposures (one at the beginning and the other at the end of the 6 min pretreatment) resulted in a significantly lower inhibition rate compared with 4 nicotine exposures ( < 0.01, =6). CONCLUSIONS etomidate reduces the excitability of the spinal ventral neurons in a concentration-dependent manner and suppresses the function of nAChR in a concentration-, voltage-, and use-dependent manner.
Animals ; Animals, Newborn ; Etomidate ; Neurons ; Patch-Clamp Techniques ; Rats ; Spinal Cord

Currently, sedation anesthesia is increasingly used in many medical fields, from gastroscopy to medical imaging. The demand for sedation anesthesia is expected to increase gradually with increasing number of day surgeries and increased expectations from medical services. The demand for sedation anesthesia is considerably higher than the available pool of anesthesiologists; therefore, in a significant number of cases, sedation anesthesia is induced by non-anesthesiologists. However, there is no systematic provision of education or expertise for non-anesthesiologists in delivering sedation anesthesia. In cases of non-anesthesiologists inducing anesthesia, social controversy is often caused by medical accidents and substance abuse. In this review, I have briefly summarized what non-anesthesiologists should know about sedation anesthesia and have presented guidelines simplifying sedation anesthesia for non-anesthesia medical personnel.
Ambulatory Surgical Procedures ; Anesthesia ; Dexmedetomidine ; Diagnostic Imaging ; Education ; Etomidate ; Gastroscopy ; Hypnotics and Sedatives ; Ketamine ; Propofol ; Substance-Related Disorders

BACKGROUND/AIMS: Recent studies have demonstrated that etomidate is a safe sedative drug with noninferior sedative effects. In our recent study, we revealed that etomidate/midazolam was more hemodynamically stable than propofol/midazolam in elderly patients undergoing colonoscopies. We aimed to investigate whether compared with propofol/midazolam, etomidate/midazolam causes fewer cardiopulmonary adverse events with noninferior efficacy for screening colonoscopies in patients of all ages. METHODS: In this single-center, randomized, double-blind study, we prospectively enrolled 200 patients. The patients were divided into etomidate and propofol groups. The primary outcome was the occurrence of cardiopulmonary adverse events. The secondary outcomes were the proportion of patients with fluctuations in vital signs (oxygen desaturation and transient hypotension), adverse events interrupting the procedure, and sedation-related outcomes. RESULTS: Adverse cardiopulmonary events were more common in the propofol group than the etomidate group (65.0% vs 51.0%, respectively; p=0.045). Forty-six patients (46.0%) in the propofol group and 29 (29.0%) in the etomidate group experienced fluctuations in their vital signs (p=0.013). The proportions of patients experiencing adverse events that interrupted the procedure, including myoclonus, were not significantly different between the two groups (etomidate: 20.0% vs propofol: 11.0%; p=0.079). Both groups had similar sedation-related outcomes. Multivariate analysis revealed that compared with the propofol groups, the etomidate group had a significantly lower risk of fluctuations in vital signs (odds ratio, 0.427; 95% confidence interval, 0.230 to 0.792; p=0.007). CONCLUSIONS: Compared with using propofol/midazolam, using etomidate/midazolam for screening colonoscopies results in more stable hemodynamic responses in patients of all ages; therefore, we recommend using etomidate/midazolam for colonoscopies in patients with cardiovascular risk factors.
Aged ; Colonoscopy ; Double-Blind Method ; Etomidate ; Hemodynamics ; Humans ; Hypnotics and Sedatives ; Mass Screening ; Midazolam ; Multivariate Analysis ; Myoclonus ; Propofol ; Prospective Studies ; Risk Factors ; Vital Signs

Eisenmenger's syndrome describes the elevation of pulmonary arterial pressure to the systemic level caused by an increased pulmonary vascular resistance with reversed or bi-directional shunt through an intracardiac or aortopulmonary communication. We report the case of 48-year-old woman with an elective total hip replacement arthroplasty for right femur neck fracture with Eisenmenger's syndrome secondary to large atrial septal defect. Anesthesia was induced with etomidate and rocuronium, maintained with desflurane 5 vol% and O₂ 3 L/min. Mirinone and norepinephrine were infused continuously to decrease right to left shunt. The patient was extubated after spontaneous breathing recovery and transferred to the intensive care unit. She was treated with mirinone, norepinephrine, dopamine, and dobutamine for hypoxemia and hypotension. After 3 hours of admission to intensive care unit, the patient had a cardiac arrest and died 30 minutes later.
Anesthesia ; Anoxia ; Arterial Pressure ; Arthroplasty ; Arthroplasty, Replacement, Hip* ; Dobutamine ; Dopamine ; Eisenmenger Complex* ; Etomidate ; Female ; Femoral Neck Fractures ; Heart Arrest ; Heart Septal Defects, Atrial ; Humans ; Hypertension, Pulmonary ; Hypotension ; Intensive Care Units ; Middle Aged ; Norepinephrine ; Respiration ; Vascular Resistance

BACKGROUND: Etomidate 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. METHODS: This 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. RESULTS: The 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). CONCLUSIONS: Priming is more effective than slow injection in reducing the incidence of myoclonus, but their effects on the severity of myoclonus are comparable.
Etomidate ; Humans ; Incidence ; Myoclonus* ; Prospective Studies

For ectopic adrenocorticotropic hormone (ACTH) syndrome (EAS), when surgery is not feasible, or in cases of severe biochemical disturbances, immunosuppression or mental instability, medical therapy with agents such as etomidate is indicated. We present our experience in using etomidate for a 41-year old female with EAS secondary to a malignant mediastinal paraganglioma. We were able to demonstrate that etomidate can be used effectively to control severe hypercortisolism in a lower dose than previously described.
Etomidate ; ACTH Syndrome, Ectopic

Despite the wide application of general anesthetic drugs in clinic, it is still unclear how these drugs induce the state of general anesthesia. Larval zebrafish has emerged as an ideal model for dissecting the mechanism of neural systems due to the conserved and simple brain structure. In the present study, we established an anesthesia model from behavioral to electrophysiological levels using larval zebrafish for the first time. Bath application of etomidate, as a kind of intravenous anesthetic drugs, suppressed the spontaneous locomotion of zebrafish in a concentration-dependent manner. Consistently, in vivo fictive motor patterns of spinal motoneurons recorded extracellularly were significantly inhibited as well. Furthermore, using in vivo extracellular recording and whole-cell recording, we found that etomidate application suppressed local field potentials (LFP) of the brain and blocked visually evoked responses of optic tectal neurons. The study indicates that larval zebrafish can serve as an ideal vertebrate animal model for studying neural mechanisms underlying general anesthesia.
Anesthesia ; Anesthetics, Intravenous ; Animals ; Etomidate ; Larva ; Locomotion ; Motor Neurons ; Patch-Clamp Techniques ; Zebrafish

BACKGROUNDEtomidate (R-1-[1-ethylphenyl] imidazole-5-ethyl ester) is a widely used anesthetic drug that had been reported to contribute to cognitive deficits after general surgery. However, its underlying mechanisms have not been fully elucidated. In this study, we aimed to explore the neurobiological mechanisms of cognitive impairments that caused by etomidate.

METHODSA total of 30 Sprague-Dawley rats were used and divided into two groups randomly to receive a single injection of etomidate or vehicle. Then, the rats' spatial memory ability and neuronal survival were evaluated using the Morris water maze test and Nissl staining, respectively. Furthermore, we analyzed levels of oxidative stress, as well as cyclic adenosine 3',5'-monophosphate response element-binding (CREB) protein phosphorylation and immediate early gene (IEG, including Arc, c-fos, and Egr1) expression levels using Western blot analysis.

RESULTSCompared with vehicle-treated rats, the etomidate-treated rats displayed impaired spatial learning (day 4: 27.26 ± 5.33 s vs. 35.52 ± 3.88 s, t = 2.988, P = 0.0068; day 5: 15.84 ± 4.02 s vs. 30.67 ± 4.23 s, t = 3.013, P = 0.0057; day 6: 9.47 ± 2.35 s vs. 25.66 ± 4.16 s, t = 3.567, P = 0.0036) and memory ability (crossing times: 4.40 ± 1.18 vs. 2.06 ± 0.80, t = 2.896, P = 0.0072; duration: 34.00 ± 4.24 s vs. 18.07 ± 4.79 s, t = 3.023, P = 0.0053; total swimming distance: 40.73 ± 3.45 cm vs. 27.40 ± 6.56 cm, t = 2.798, P = 0.0086) but no neuronal death. Furthermore, etomidate did not cause oxidative stress or deficits in CREB phosphorylation. The levels of multiple IEGs (Arc: vehicle treated rats 100%, etomidate treated rats 86%, t = 2.876, P = 0.0086; c-fos: Vehicle treated rats 100%, etomidate treated rats 72%, t = 2.996, P = 0.0076; Egr1: Vehicle treated rats 100%, etomidate treated rats 58%, t = 3.011, P = 0.0057) were significantly reduced in hippocampi of etomidate-treated rats.

CONCLUSIONOur data suggested that etomidate might induce memory impairment in rats via inhibition of IEG expression.

Anesthesia ; adverse effects ; Animals ; Etomidate ; adverse effects ; Hippocampus ; drug effects ; metabolism ; Hypnotics and Sedatives ; adverse effects ; Immediate-Early Proteins ; genetics ; metabolism ; Maze Learning ; drug effects ; Memory Disorders ; chemically induced ; genetics ; Rats ; Rats, Sprague-Dawley