Long-term use of etomidate disrupts the intestinal homeostasis and nervous system in mice

Etomidate (ETO) is used as an anesthetic in surgery, but it is being abused in some populations. The damage caused by long-term intake of ETO to intestinal and brain functions is not yet clear, and it remains to be determined whether the drug affects the central nervous system through the gut-brain axis. This study aimed to investigate the neurotoxic and gastrointestinal effects of ETO at doses of 1 mg/kg and 3 mg/kg in mice over 14 consecutive days. The results showed that long-term injection of ETO led to drug resistance in mice, affecting their innate preference for darkness and possibly inducing dependence on ETO. The levels of 5-hydroxytryptamine in the brain, serum, and colon decreased by 37%, 51%, and 42% respectively, while the levels of γ-aminobutyric acid reduced by 38%, 52%, and 41% respectively. H&E staining revealed that ETO reduced goblet cells in the colon and damaged the intestinal barrier. The expression of tight junction-related genes Claudin4 and ZO-1 was downregulated. The intestinal flora changed, the abundance of Akkermansia and Lactobacillus decreased by 33% and 14%, respectively, while Klebsiella increased by 18%. TUNEL results showed that high-dose ETO increased apoptotic cells in the brain. The expression of Claudin1 in the brain was downregulated. Untargeted metabolomics analysis of the colon and brain indicated that ETO caused abnormalities in glycerophospholipid metabolism. Abnormal lipid metabolism might lead to the production or accumulation of lipotoxic metabolites, causing central nervous system diseases. ETO induced changes in the intestinal flora and metabolism, further affecting the central nervous system through the gut-brain axis. The study unveiled the detrimental effects on the brain and gastrointestinal system resulting from long-term intake of ETO, which holds significant implications for comprehending the adverse impact of ETO abuse on human health.

A case of fatal poisoning caused by etomidate: evidence from pathological and toxicological analyses

Etomidate is a nonbarbiturate sedative derived from imidazole. Prolonged and excessive use of etomidate can lead to the suppression of adrenocortical function, myoclonus, and even death. This report describes a rare case of a 47-year-old man who died from acute intoxication after oral ingestion of liquid containing etomidate. The cause of death was conclusively attributed to etomidate based on a comprehensive investigation, including autopsy, histopathological examination, toxicological analysis, and biochemical analysis. This is the first reported case of a fatality solely resulting from the oral ingestion of etomidate, which can provide valuable insights for future forensic investigations involving etomidate poisoning. Therefore, it is imperative to share this case with the scientific community.

Etomidate inhibits tumor growth of glioblastoma by regulating M1 macrophage polarization

Glioblastoma (GBM) is a common primary central nervous system tumor. Although the multimodal integrated treatment for GBM has made great progress in recent years, the overall survival time of GBM is still short. Thus, novel treatments for GBM are worth further investigation and exploration. This study aimed to investigate the effects of etomidate on GBM tumor growth and the underlying mechanism. A xenograft tumor model was established and treated with etomidate to assess tumor growth. Immunohistochemistry (IHC) assay evaluated the positive rate of Ki67 cells in tumor tissues. Cell counting kit (CCK)-8 and EdU assays accessed the cell viability and proliferation. Immunofluorescence (IF) staining detected the distribution of macrophage markers in tumor tissues. The percentages of M1- and M2-like macrophages in tumor-associated macrophages (TAMs) and co-culture system (macrophages and GBM cells) were detected using flow cytometry. Macrophage polarization-related genes were measured using reverse transcription-quantitative polymerase chain reaction (RT-qPCR). Etomidate treatment inhibited the tumor growth, and increased the CD86+ cells but decreased the CD206+ cells in TAMs. The gene expression of M1 markers was increased in TAMs of etomidate-treated mice, whereas that of M2 markers was decreased. Moreover, etomidate treatment increased the number of CD86+ M1-like macrophages co-cultured with tumor cells but decreased that of CD206+ M2-like macrophages, with the upregulation of M1 markers and downregulation of M2 markers. Etomidate inhibited GBM tumor growth by promoting M1 macrophage polarization, suggesting a new insight into the clinical treatment of GBM.

Etomidate enhances cerebellar CF-PC synaptic plasticity through CB1 receptor/PKA cascade in vitro in mice

Etomidate (ET) is a widely used intravenous imidazole general anesthetic, which depresses the cerebellar neuronal activity by modulating various receptors activity and synaptic transmission. In this study, we investigated the effects of ET on the cerebellar climbing fiber-Purkinje cells (CF-PC) plasticity in vitro in mice using whole-cell recording technique and pharmacological methods. Our results demonstrated that CF tetanic stimulation produced a mGluR1-dependent long-term depression (LTD) of CF-PC excitatory postsynaptic currents (EPSCs), which was enhanced by bath application of ET (10 µM). Blockade of mGluR1 receptor with JNJ16259685, ET triggered the tetanic stimulation to induce a CF-PC LTD accompanied with an increase in paired-pulse ratio (PPR). The ET-triggered CF-PC LTD was abolished by extracellular administration of an N-methyl-(D)-aspartate (NMDA) receptor antagonist, D-APV, as well as by intracellular blockade of NMDA receptors activity with MK801. Furthermore, blocking cannabinoids 1 (CB1) receptor with AM251 or chelating intracellular Ca2+ with BAPTA, ET failed to trigger the CF-PC LTD. Moreover, the ET-triggered CF-PC LTD was abolished by inhibition of protein kinase A (PKA), but not by inhibition of protein kinase C inhibiter. The present results suggest that ET acts on postsynaptic NMDA receptor resulting in an enhancement of the cerebellar CF-PC LTD through CB1 receptor/PKA cascade in vitro in mice. These results provide new evidence and possible mechanism for ET anesthesia to affect motor learning and motor coordination by regulating cerebellar CF-PC LTD.

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.

Effects of propofol on presynaptic synapsin phosphorylation in the mouse brain in vivo

The commonly used general anesthetic propofol can enhance the γ-aminobutyric acid-mediated inhibitory synaptic transmission and depress the glutamatergic excitatory synaptic transmission to achieve general anesthesia and other outcomes. In addition to the actions at postsynaptic sites, the modulation of presynaptic activity by propofol is thought to contribute to neurophysiological effects of the anesthetic, although potential targets of propofol within presynaptic nerve terminals are incompletely studied at present. In this study, we explored the possible linkage of propofol to synapsins, a family of neuron-specific phosphoproteins which are the most abundant proteins on presynaptic vesicles, in the adult mouse brain in vivo. We found that an intraperitoneal injection of propofol at a dose that caused loss of righting reflex increased basal levels of synapsin phosphorylation at the major representative phosphorylation sites (serine 9, serine 62/67, and serine 603) in the prefrontal cortex (PFC) of male and female mice. Propofol also elevated synapsin phosphorylation at these sites in the striatum and S9 and S62/67 phosphorylation in the hippocampus, while propofol had no effect on tyrosine hydroxylase phosphorylation in striatal nerve terminals. Total synapsin protein expression in the PFC, hippocampus, and striatum was not altered by propofol. These results reveal that synapsin could be a novel substrate of propofol in the presynaptic neurotransmitter release machinery. Propofol possesses the ability to upregulate synapsin phosphorylation in broad mouse brain regions.

Comparison of induction agents for rapid sequence intubation in refractory status epilepticus: A single-center retrospective analysis

Endotracheal intubation, frequently required during management of refractory status epilepticus (RSE), can be facilitated by anesthetic medications; however, their effectiveness for RSE control is unknown. We performed a single-center retrospective review of patients admitted to a neurocritical care unit (NCCU) who underwent in-hospital intubation during RSE management. Patients intubated with propofol, ketamine, or benzodiazepines, termed anti-seizure induction (ASI), were compared to patients who received etomidate induction (EI). The primary endpoint was clinical or electrographic seizures within 12 h post-intubation. We estimated the association of ASI on post-intubation seizure using logistic regression. A sub-group of patients undergoing electroencephalography during intubation was identified to evaluate the immediate effect of ASI on RSE. We screened 697 patients admitted to the NCCU for RSE and identified 148 intubated in-hospital (n = 90 ASI, n = 58 EI). There was no difference in post-intubation seizure (26 % (n = 23) ASI, 29 % (n = 17) EI) in the cohort, however, there was increased RSE resolution with ASI in 24 patients with electrographic RSE during intubation (ASI: 61 % (n = 11/18) vs EI: 0 % (n = 0/6), p =.016). While anti-seizure induction did not appear to affect post-intubation seizure occurrence overall, a sub-group of patients undergoing electroencephalography during intubation had a higher incidence of seizure cessation, suggesting potential benefit in an enriched population.

A highly efficient liquid chromatography-tandem mass spectrometry (LC-MS/MS) assay for etomidate and etomidate acid in urine, liver and kidney

Etomidate (ETO) is a highly-efficient drug that can induce anesthesia with increasing doses, thus subject to strict regulation. However, an accurate and efficient method for ETO intake detection is currently lacking. Therefore, this study developed a straightforward sample preparation method using LC-MS/MS to analyze ETO and its primary metabolite, etomidate acid (ETA), in urine, liver, and kidney samples. Snap frozen pig liver and kidney samples were ground into a fine powder. Then, all the biological samples, including human urine, pig liver and kidney tissues, were deproteinized using acetonitrile and filtered for analysis. The separation was achieved in 9.01 min with gradient elution. The calibration curves ranged from 0.5 to 50 ng/mL for ETO in urine and 0.5 to 50 ng/g in liver and kidney, while the curves ranged from 1 to 100 ng/mL for ETA in urine and 1 to 100 ng/g in liver and kidney. The correlation coefficients (R2) were greater than 0.9957. The Limit of detection (LOD) and limit of quantitation (LOQ) for ETO were 0.2 and 0.5 ng/mL in urine samples and 0.2 and 0.5 ng/g in liver and kidney samples, respectively. For ETA, the LOD and LOQ were 0.5 and 1 ng/mL in urine samples and 0.5 and 1 ng/g in liver and kidney samples. This method was assessed by validation parameters, including selectivity, intra- and inter-day precision and accuracy, recovery, matrix effect, dilution integrity and stability. It was successfully applied to a practical case, revealing ETO and ETA concentrations in urine of 1.01 and 5.58 μg/mL, in liver samples of 12.30 and 1.13 μg/g, and in kidney samples of 6.95 and 4.23 μg/g. This suggests that the method is suitable for routine forensic detection of illicit ETO abuse.

Etomidate versus propofol for electroconvulsive therapy: An intraindividual comparative study during the COVID-19 pandemic

OBJECTIVES

The Coronavirus disease 2019 (COVID-19) pandemic markedly influenced mental health care practices, notably regarding electroconvulsive therapy (ECT). This was due to the redistribution of anesthetic agents used during ECT such as propofol, for intensive care units. Because in our center propofol was switched to etomidate to avoid ECT activity discontinuation, we undertook this study in order to compare Propofol and Etomidate regarding electroencephalographic seizure duration and stimulus intensity.

METHODS

We performed a retrospective and comparative study, each patient being its own control. We included patients with at least two courses of ECT on propofol and two others with etomidate over the period from September 2019 to April 2021, regardless of the psychiatric diagnosis. Our data collection process notably targeted stimulus intensity, seizure duration recorded using electroencephalography, and medication used for anesthetic induction.

RESULTS

Overall, we included 18 patients with a male: female ratio of 1:2.6 and a mean (and standard deviation) age of 62.7±13.4 years. We found that the mean intensity of stimulation was significantly lower with etomidate when compared to propofol (425.3±250.0 vs. 658.9±280.2 mC, P=0.001). The mean duration of electroencephalographic seizure was significantly higher with etomidate in comparison to propofol (53.5±16.6 vs. 35.0±12.2seconds, P<0.001).

CONCLUSION

By using each patient as its own control, our study found that etomidate, while compared to propofol, was related to a lower level of stimulatory intensity and a longer electroencephalographic seizure duration.

Etomidate Improves the Antidepressant Effect of Electroconvulsive Therapy by Suppressing Hippocampal Neuronal Ferroptosis via Upregulating BDNF/Nrf2

Electroconvulsive therapy (ECT) performed under general anesthesia is an effective treatment for severe depression. Etomidate is an intravenous anesthetic that shows beneficial effects on ECT. However, the potential mechanisms have rarely been reported. In this study, male rats were exposed to chronic unpredictable mild stress for 4 weeks, followed by ECT for 10 days, with or without intervention with ferrostatin-1 (2 mg/kg) or all-trans retinoic acid (ATRA, 5 mg/kg). Rats subjected to etomidate (20 mg/kg) or propofol (120 mg/kg) treatment were administered with designated anesthetic before ECT. Compared to depressive rats without ECT, those who received ECT showed increased numbers of hippocampal neurons, increased expression of negative regulators of ferroptosis including glutathione peroxidase 4, ferritin heavy chain 1, and ferroptosis suppressor protein 1, upregulation of brain-derived neurotrophic factor and nuclear factor erythroid 2-related factor, and downregulation of acyl-CoA synthetase long-chain family member 4, a positive regulator of ferroptosis in the hippocampus. Additionally, compared with propofol, etomidate used in ECT resulted in higher upregulation of BDNF/Nrf2 and inhibited neuronal ferroptosis in hippocampus. These results showed etomidate may enhance the antidepressant effect of ECT by protecting hippocampal neurons against ferroptosis.

Etomidate in the treatment of Cushing syndrome

Cushing syndrome is a metabolic disease caused by chronic exposure to high levels of glucocorticoids. It can present as an endocrine emergency due to a rapid increase in circulating cortisol leading to increased risk of cardiovascular disease and infection. Etomidate rapidly reduces plasma cortisol levels by inhibiting the action of 11β-hidroxilase. We report the case of a patient with severe hypercortisolaemia accompanied by metabolic and psychiatric disorders in whom administration of etomidate reduced preoperative levels of cortisol.

Etomidate as an induction agent for endotracheal intubation in critically ill patients: A meta-analysis of randomized trials

PURPOSE

We performed a meta-analysis of randomized controlled trials to evaluate if etomidate impacted mortality in critically ill adults when compared with other induction agents.

MATERIALS AND METHODS

We searched PubMed, Embase, and the Cochrane Central Register of Controlled Trials for randomized controlled trials which compared etomidate with any other induction agent in critically ill adult patients undergoing endotracheal intubation. The primary outcome was mortality at the main timepoint defined by the study. We conducted a fixed-effects meta-analysis for the risk ratio. Using that risk ratio and 95% confidence interval, we then estimated the probability of any harm (RR > 1) and the number needed to harm ≤100 (RR ≥ 1.05).

RESULTS

We included 11 randomized trials comprising 2704 patients. We found that etomidate increased mortality (319/1359 [23%] vs. 267/1345 [20%]; risk ratio (RR) = 1.16; 95% confidence interval (CI), 1.01-1.33; P = 0.03; I2 = 0%; number needed to harm = 31). The probabilities of any increase and a 1% increase (NNH ≤100) in mortality were 98.1% and 92.1%, respectively.

CONCLUSIONS

This meta-analysis found a high probability that etomidate increases mortality when used as an induction agent in critically ill patients with a number needed to harm of 31.

Bilirubin potentiates etomidate-induced sedation by enhancing GABA-induced currents after bile duct ligation

OBJECTIVES

Our previous clinical trial showed that etomidate requirements to reach an appropriate level of anesthesia in patients with obstructive jaundice were reduced, which means that these patients are more sensitive to etomidate. However, the mechanism is still not completely clear. The present study was aimed to investigate the mechanism by which bilirubin facilitates etomidate induced sedation.

METHODS

A bile duct ligation (BDL) rat model was used to simulate obstructive jaundice. Anesthesia sensitivity to etomidate was determined by the time to loss of righting reflex (LORR). Intrathecal injection of bilirubin was used to test the effects of bilirubin on etomidate induced sedation. The modulating effects of bilirubin on GABA responses were studied using the whole-cell patch clamp technique.

RESULTS

The time to LORR induced by etomidate was significantly decreased in the BDL groups (p < 0.05), and unconjugated bilirubin in serum and cerebrospinal fluid (CSF) were markedly increased (p < 0.05). The time to LORR induced by etomidate was decreased after intrathecal injection of bilirubin (p < 0.05). A bilirubin concentration of 1.0 μM increased the GABA-induced currents of rat cortical pyramidal neurons (p < 0.05). Furthermore, 1.0 μM bilirubin enhanced GABA-induced currents modulated by etomidate (p < 0.05).

CONCLUSIONS

Our results demonstrated that pathologic bilirubin in CSF could enhance etomidate induced sedation. The mechanism may be that bilirubin increase the GABA-induced currents of rat pyramidal neurons.

Etomidate Depresses Spontaneous Complex Spikes Activity of Cerebellar Purkinje Cells via Cannabinoid 1 Receptor in vivo in Mice

INTRODUCTION

Complex spikes (CSs) activity of cerebellar Purkinje cells plays critical roles in motor coordination and motor learning by transferring information to cerebellar cortex, which is an accessible and useful model for neurophysiological investigation. Etomidate is an ultrashort-acting nonbarbiturate intravenous anesthetic, which inhibits the spontaneous activity of cerebellar Purkinje cells through activation of GABAA and glycine receptors in vivo in mice. However, the effect of etomidate on the spontaneous CSs activity of cerebellar Purkinje cells in living mouse is not clear.

METHODS

We here investigated the effects of etomidate on spontaneous CSs activity of cerebellar Purkinje cell in urethane-anesthetized mice by electrophysiology recording technique and pharmacological methods.

RESULTS

Our results showed that cerebellar surface perfusion of etomidate significantly depressed the activity of spontaneous CSs, which exhibited decreases in the number of spikelets and the area under curve (AUC) of the CSs. The etomidate-produced inhibition of CSs activity was persisted in the presence of GABAA and glycine receptors antagonists. However, application of cannabinoid 1 (CB1) receptor antagonist, AM-251, completely blocked the etomidate-induced inhibition of CSs. Furthermore, application of the CB1 receptor agonist, WIN55212-2, induced a decrease of CSs. Moreover, in the presence of a specific protein kinase A (PKA) inhibitor, KT5720, etomidate failed to produce decreases in the spikelets number and the AUC of the spontaneous CSs.

CONCLUSION

These results indicate that cerebellar surface application of etomidate facilitates CB1 receptor activity resulting in a depression of spontaneous CSs activity of Purkinje cells via PKA signaling pathway in mouse cerebellar cortex. Our present results suggest that the etomidate administration may impair the function of cerebellar cortical neuronal circuitry by inhibition of the climbing fiber - Purkinje cells synaptic transmission through activation of CB1 receptors in vivo in mice.

Efficacy of Granisetron versus Sufentanil on Reducing Myoclonic Movements Following Etomidate: Double-blind, randomised clinical trial

Objectives

This study aimed to reduce the intensity of myoclonus movements by comparing the effectiveness of granisetron and sufentanil in reducing the intensity of etomidate-induced myoclonic movements. Etomidate-induced myoclonus occurs in up to 85% of patients under general anaesthesia. This type of myoclonus can induce significant clinical and economic problems in patients with special conditions.

Methods

This double-blind randomised clinical trial study consisted of 96 adult patients recruited between January and July 2021 from Mashhad University of Medical Sciences, Mashhad, Iran. Using block randomisation, subjects were divided into three groups of 32 patients: the group receiving granisetron 40 μg/kg (group G), the group receiving sufentanil 0.2 μg/kg (group S) and the control group who did not receive the pretreatment (group C). Patients received these medications as pretreatments 120 seconds before induction with etomidate. After the injection of etomidate with a dose of 0.3 mg/kg, the incidence of myoclonus was evaluated. After evaluating the myoclonus, the full dose of narcotics (fentanyl 1 μg/kg) and muscle relaxants (atracurium 0.5 mg/kg) were administered to patients and a suitable airway was established for them.

Results

The findings indicated that granisetron reduced the intensity and incidence of myoclonic movements more than sufentanil. In addition, myoclonic movements were observed at a significantly higher intensity in the control group (P = 0.001).

Conclusion

The results obtained from the current study indicate that granisetron and sufentanil as pretreatments are effective for reducing myoclonus in patients.

The effect-site concentration of remifentanil blunting endotracheal intubation responses during anesthesia induction with etomidate: a dose-finding study

BACKGROUND

Remifentanil can inhibit the hemodynamic responses caused by endotracheal intubation, but the effect-site concentration of it required to control intubation responses when combined with etomidate has not been demonstrated. The purpose of this study was to determine the effect-site concentration of remifentanil blunting tracheal intubation responses in 50% and 95% of patients (EC₅₀ and EC₉₅) during etomidate anesthesia.

METHODS

American Society of Anesthesiologists physical status (ASA) I-II elective surgical patients receiving target-controlled infusion (TCI) of remifentanil, followed by etomidate and rocuronium for anesthesia were enrolled. The Belive Drive A2 monitor was used to calculate the MGRSSI (Maygreen Sedative state index) of hypnotic effect and the MGRNOX (Maygreen Nociception index) of nociception. The MGRSSI and the MGRNOX value were generated every 1 s. Mean arterial pressure (MAP) and heart rate (HR) were measured every minute, noninvasively. Using the modified Dixon's up-and-down method, the concentration of remifentanil was determined based on the intubation response of the previous patient. The cardiovascular response during endotracheal intubation was defined as positive when MAP or HR is 20% higher than the pre-intubation value. A probit analysis was used for calculating EC₅₀, EC₉₅ and 95% confidence interval (CI).

RESULTS

The EC₅₀ and EC₉₅ of remifentanil blunting tracheal intubation responses were found to be 7.731 ng/ml (95%CI: 7.212-8.278 ng/ml) and 8.701 ng/ml (95%CI: 8.199-11.834 ng/ml). There were statistically significant increases in HR, MGRSSI and MGRNOX value to tracheal intubation in the positive responses group compared to the negative group. The most common adverse event was postoperative nausea and vomiting, which occurred in 3 patients.

CONCLUSION

Remifentanil effect-site concentration of 7.731 ng/ml is effective in blunting sympathetic responses to tracheal intubation in 50% of patients when combined with etomidate anesthesia.

TRIAL REGISTRATION

The trial was registered at the Chinese Clinical Trials Registry ( www.chictr.org.cn , registration number: ChiCTR2100054565, date of registration: 20/12/2021).

Ketamine versus etomidate for rapid sequence intubation in patients with trauma: a retrospective study in a level 1 trauma center in Korea

BACKGROUND

Ketamine and etomidate are commonly used as sedatives in rapid sequence intubation (RSI). However, there is no consensus on which agent should be favored when treating patients with trauma. This study aimed to compare the effects of ketamine and etomidate on first-pass success and outcomes of patients with trauma after RSI-facilitated emergency intubation.

METHODS

We retrospectively reviewed 944 patients who underwent endotracheal intubation in a trauma bay at a Korean level 1 trauma center between January 2019 and December 2021. Outcomes were compared between the ketamine and etomidate groups after propensity score matching to balance the overall distribution between the two groups.

RESULTS

In total, 620 patients were included in the analysis, of which 118 (19.9%) were administered ketamine and the remaining 502 (80.1%) were treated with etomidate. Patients in the ketamine group showed a significantly faster initial heart rate (105.0 ± 25.7 vs. 97.7 ± 23.6, p = 0.003), were more hypotensive (114.2 ± 32.8 mmHg vs. 139.3 ± 34.4 mmHg, p < 0.001), and had higher Glasgow Coma Scale (9.1 ± 4.0 vs. 8.2 ± 4.0, p = 0.031) and Injury Severity Score (32.5 ± 16.3 vs. 27.0 ± 13.3, p < 0.001) than those in the etomidate group. There were no significant differences in the first-pass success rate (90.7% vs. 90.1%, p > 0.999), final mortality (16.1% vs. 20.6, p = 0.348), length of stay in the intensive care unit (days) (8 [4, 15] (Interquartile range)), vs. 10 [4, 21], p = 0.998), ventilator days (4 [2, 10] vs. 5 [2, 13], p = 0.735), and hospital stay (days) (24.5 [10.25, 38.5] vs. 22 [8, 40], p = 0.322) in the 1:3 propensity score matching analysis.

CONCLUSION

In this retrospective study of trauma resuscitation, those receiving intubation with ketamine had greater hemodynamic instability than those receiving etomidate. However, there was no significant difference in clinical outcomes between patients sedated with ketamine and those treated with etomidate.

Effect of vitamin C on adrenal suppression following etomidate for rapid sequence induction in trauma patients: a randomized clinical trial

BACKGROUND

Etomidate is an imidazole derivative that is widely used in the emergency department for Rapid Sequence Intubation (RSI). Although it has a safe hemodynamic profile, there are some concerns about its suppressant effects on the adreno-cortical axis. Vitamin C, as an antioxidant, can play a protective role in this issue.

METHOD

In a controlled clinical trial, we studied adult traumatic patients who needed RSI with etomidate. In one group underwent RSI with etomidate and cortisol levels were measured three hours later. In the other group, we administered one gram of vitamin C before etomidate administration, and the cortisol level was measured three hours later.

RESULTS

Fifty-one patients have been studied. The serum cortisol level was significantly lower after RSI with etomidate in both groups. In the Vitamin C group, there was a significantly higher cortisol level after RSI in comparison to the control group.

CONCLUSION

Etomidate can suppress the cortisol level in trauma patients who undergo RSI. Vitamin C can reduce this suppressant effect of etomidate.

TRIAL REGISTRATION

IRCT registration number: IRCT20090923002496N11, URL of trial registry record: https://en.irct.ir/trial/34586 , Date of trial registration: 19/04/2019. Full date of the first registration: 30/05/2019.

Etomidate-ketamine versus dexmedetomidine-ketamine for entropy-guided procedural sedation during endoscopic retrograde cholangiopancreatography procedures: A randomized single blind study

BACKGROUND AND AIMS

The major challenge for the anesthetist in endoscopic retrograde cholangiopancreatography (ERCP) procedures is to provide moderate to deep levels of sedation in prone position with preservation of spontaneous respiratory efforts in shared airway scenario with an endoscopist. These patients have other comorbidities, making them vulnerable to complications during the routinely used sedation with propofol. We compared the entropy-guided efficacy of combination of etomidate-ketamine to dexmedetomidine-ketamine in patients undergoing ERCP.

METHODS

This prospective single blind randomized entropy-guided trial was conducted on 60 patients with etomidate-ketamine in group I (n = 30) and dexmedetomidine-ketamine in group II (n = 30). The purpose was to compare etomidate-ketamine versus dexmedetomidine-ketamine for ERCP in terms of intraprocedural hemodynamics with desaturation, onset of sedation, recovery time and endoscopist's satisfaction.

RESULTS

Hypotension was observed only in six (20%) patients of group II (p < 0.009). Two patients of group I and three in group II desaturated (Spo2 < 90) briefly during the procedure, but none of the patient required intubation (p > 0.05). The mean time in minutes of onset of sedation was 1.15 in group I and 5.6 in group II (p < 0.001). Endoscopists' satisfaction was better in group I (p ≤ 0.001) and length of recovery room stay was shorter in group I as compared to that in group II (p ≤ 0.007).

CONCLUSION

We conclude that entropy-guided intravenous procedural sedation with etomidate-ketamine combination provides faster onset of sedation, stable periprocedural hemodynamics, rapid recovery and fair to excellent endoscopist satisfaction compared to dexmedetomidine-ketamine combination for ERCP.

Accidental Intrathecal Injection of Etomidate During Spinal Anesthesia: A Case Report

Etomidate is an ultra-short-acting anesthetic agent derived from imidazole that can only be administered intravenously. Etomidate has excellent hemodynamic properties in inducing anesthesia, making it an ideal choice for patients with shock, hypovolemia, or significant cardiovascular disease, with minimal reduction in blood pressure. We report a case of a female patient who was given accidental etomidate intrathecally instead of ropivacaine because of its similar appearance, which led to a slight decrease in blood pressure and no change in the pulse rate. The patient had stable vital signs and no neurological complications.

Effect of remimazolam tosilate versus etomidate on hemodynamics in patients undergoing valve replacement surgery: study protocol for a randomized controlled trial

BACKGROUND

Patients with a history of cardiac disease are prone to develop cardiovascular adverse events such as hypotension, hypertension, and tachycardia during anesthesia induction. Therefore, hemodynamic stability is one of the most important concerns for induction of anesthesia in patients undergoing cardiac surgery. Remimazolam tosilate is a new, ultra-short-acting benzodiazepine agent, with the advantages of rapid onset, rapid offset, and minimal cardiorespiratory depression. We aim to compare the effect of remimazolam tosilate and etomidate on hemodynamics during anesthesia induction in patients undergoing valve replacement surgery.

METHODS/DESIGN

The trial is a prospective, randomized, double-blinded, controlled, single-center trial to compare the effect of remimazolam tosilate and etomidate on hemodynamics in patients undergoing valve replacement surgery. One hundred seventeen patients undergoing selective valve replacement surgery between January 1, 2022, and December 31, 2023, will be enrolled and randomly allocated into one of three groups: low-dose remimazolam group (Group LR), high-dose remimazolam group (Group HR), or etomidate group (Group E). The primary outcome is hemodynamic fluctuations during anesthesia induction (the difference between mean arterial pressure [MAP] to baseline, ▴MAP; and the difference between maximum or minimum heart rate [HR] and baseline, ▴HR). Secondary outcomes include the incidence of adverse cardiovascular events (hypotension, severe bradycardia, hypertension, tachycardia, and arrhythmia), the cumulative doses of vasoactive drugs used per patient, incidence and degree of injection pain and myoclonus, blood glucose values, and vital signs at different time points.

DISCUSSION

This research will determine the effectiveness and safety of remimazolam tosilate induction on hemodynamics in patients undergoing valve replacement surgery.

TRIAL REGISTRATION

www.chictr.org .cn identifier ChiCTR2100052535 . Registered on 17th Dec 2021, http://www.chictr.org.cn/ ).

Efficacy and safety of remimazolam for non-obese patients during anesthetic induction in cardiac surgery: study protocol for a multicenter randomized trial

BACKGROUND

Valvular heart disease remains common in both developed and developing countries, and it requires timely surgical treatment when necessary. However, the stability of hemodynamics during anesthesia induction in patients undergoing valve replacement surgery is difficult to maintain due to their impaired cardiac function. Remimazolam, a novel and ultrashort-acting intravenous sedative-hypnotic, may be beneficial to stable hemodynamics, but the evidence is limited. Therefore, this study aims to evaluate the effect of remimazolam induction on hemodynamics compared with midazolam and etomidate in patients undergoing valve replacement surgery.

METHODS

This is a prospective, multicenter randomized controlled trial (RCT). Three hundred and sixty-three non-obese adult patients aged 45 to 80 years old undergoing valve surgery with cardiopulmonary bypass will be randomly allocated to receive remimazolam tosilate, midazolam, or etomidate during anesthetic induction. The primary outcome is the incidence of hypotension within 20 min after the administration of investigated drugs. The hypotension is defined as systolic blood pressure (SBP) < 90 mmHg or a 30% reduction in SBP from baseline or the application of vasoactive drugs. Secondary outcomes include incidence of successful sedation, time to successful sedation, incidence of delirium and postoperative low cardiac output syndrome within 7 days after surgery, hospital mortality, mechanical ventilation time, ICU length of stay, and hospital length of stay.

DISCUSSION

To our knowledge, this is the first prospective RCT to investigate the efficacy and safety of remimazolam induction in adult cardiac surgery compared with midazolam and etomidate. This study will provide important information on the application of remimazolam in cardiac surgery in the future.

TRIAL REGISTRATION

Chinese Clinical Trial Registry chictr.org.cn ChiCTR2100050122. Registered on August 16, 2021.

Cushing's syndrome: a combined treatment with etomidate and osilodrostat in severe life-threatening hypercortisolemia

Endogenous Cushing's syndrome (CS) is associated with increased morbidity and mortality. Early diagnosis and initiation of therapy are essential, but effective treatment remains a challenge. In a long-term follow-up, biochemical control of hypercortisolemia, especially when severe, is difficult to achieve. Life-threatening hypercortisolemia is difficult to control due to the limitations of pharmacotherapy, including its side effects, and may require etomidate infusion in the intensive care unit (ICU) to rapidly lower cortisol levels. The effectiveness of hypercortisolemia management can be increased by a dual blockade of cortisol production. We report the efficacy, safety, and tolerability of combined therapy with two steroidogenesis inhibitors, etomidate, and osilodrostat, in a 32-year-old woman diagnosed with severe ACTH-dependent hypercortisolemia, subsequently maintaining a stable level of cortisol with osilodrostat monotherapy. This approach enabled achievement of relatively rapid control of the hypercortisolemia while using an etomidate infusion and concomitant increasing doses of oral osilodrostat applying a "titrations strategy." Our experience shows that it is worth taking advantage of the synergistic anticortisolic action of etomidate with osilodrostat.

A systematic review and meta-analysis of the hemodynamic effects of etomidate versus other sedatives in patients undergoing rapid sequence intubation

INTRODUCTION

Rapid sequence intubation is an airway rescue and protection technique in which different sedatives are used to perform orotracheal intubation. Etomidate, due to its pharmacokinetic and pharmacodynamic qualities, particularly hemodynamic stability, is the most widely used sedative in this scenario. However, its superiority over other sedatives is controversial.

MATERIALS AND METHODS

We performed a meta-analysis using a pre-designed protocol and PRISMA guidelines to evaluate the mean difference between systolic blood pressure before and after administration of the sedative. We also analyzed the relative risks of hypotension.

RESULTS

Ten studies were included. The incidence of hypotension in patients receiving etomidate ranged from 6.4% to 75.2%, and between 24.0% and 65.9% in patients receiving other sedatives. No significant differences were found in the mean difference in systolic blood pressure during pre-intubation 0.01 mm Hg (95% CI: -0.90; 0.92) or in post-intubation 0.98 mmHg (95% CI: -0.24; 2.20). The relative risk analysis showed that the risk of hypotension is equal to an RR of 1.19 (95% CI: 0.92-1.54) between those who received etomidate and those who received the other sedatives.

CONCLUSIONS

The risk of hypotension after rapid intubation sequence with etomidate does not differ significantly compared to other sedatives. However, the studies included in this review were heterogeneous.

Ketamine is not associated with more post-intubation hypotension than etomidate in patients undergoing endotracheal intubation

INTRODUCTION

Emergency department (ED) patients undergoing emergent tracheal intubation often have multiple physiologic derangements putting them at risk for post-intubation hypotension. Prior work has shown that post-intubation hypotension is independently associated with increased morbidity and mortality. The choice of induction agent may be associated with post-intubation hypotension. Etomidate and ketamine are two of the most commonly used agents in the ED, however, there is controversy regarding whether either agent is superior in the setting of hemodynamic instability. The goal of this study is to determine whether there is a difference in the rate of post-intubation hypotension who received either ketamine or etomidate for induction. Additionally, we provide a subgroup analysis of patients at pre-existing risk of cardiovascular collapse (identified by pre-intubation shock index (SI) > 0.9) to determine if differences in rates of post-intubation hypotension exist as a function of sedative choice administered during tracheal intubation in these high-risk patients. We hypothesize that there is no difference in the incidence of post-intubation hypotension in patients who receive ketamine versus etomidate.

METHODS

A retrospective cohort study was conducted on a database of 469 patients having undergone emergent intubation with either etomidate or ketamine induction at a large academic health system. Patients were identified by automatic query of the electronic health records from 1/1/2016-6/30/2019. Exclusion criteria were patients <18-years-old, tracheal intubation performed outside of the ED, incomplete peri-intubation vital signs, or cardiac arrest prior to intubation. Patients at high risk for hemodynamic collapse in the post-intubation period were identified by a pre-intubation SI > 0.9. The primary outcome was the incidence of post-intubation hypotension (systolic blood pressure < 90 mmHg or mean arterial pressure < 65 mmHg). Secondary outcomes included post-intubation vasopressor use and mortality. These analyses were performed on the full cohort and an exploratory analysis in patients with SI > 0.9. We also report adjusted odds ratios (aOR) from a multivariable logistic regression model of the entire cohort controlling for plausible confounding variables to determine independent factors associated with post-intubation hypotension.

RESULTS

A total of 358 patients were included (etomidate: 272; ketamine: 86). The mean pre-intubation SI was higher in the group that received ketamine than etomidate, (0.97 vs. 0.83, difference: -0.14 (95%, CI -0.2 to -0.1). The incidence of post-intubation hypotension was greater in the ketamine group prior to SI stratification (difference: -10%, 95% CI -20.9% to -0.1%). Emergency physicians were more likely to use ketamine in patients with SI > 0.9. In our multivariate logistic regression analysis, choice of induction agent was not associated with post-intubation hypotension (aOR 1.45, 95% CI 0.79 to 2.65). We found that pre-intubation shock index was the strongest predictor of post-intubation hypotension.

CONCLUSION

In our cohort of patients undergoing emergent tracheal intubation, ketamine was used more often for patients with an elevated shock index. We did not identify an association between the incidence of post-intubation hypotension and induction agent between ketamine and etomidate. Patients with an elevated shock index were at higher risk of cardiovascular collapse regardless of the choice of ketamine or etomidate.

Comparison of the Sedative, Hemodynamic, and Anesthetic Effect of Dexmedetomidine, Ketamine, and Etomidate on Cataract Surgery by Phacoemulsification Method: A Randomized Clinical Trial

Purpose

To compare dexmedetomidine, ketamine, and etomidate in the induction of sedation and hemodynamic changes in patients undergoing cataract surgery by phacoemulsification method.

Methods

This was a double-blind clinical trial study carried out on 128 patients. Using the block randomization method, the patients were divided into four equal groups (dexmedetomidine, ketamine, etomidate, and control). Mean arterial pressure, heart rate, and arterial oxygen saturation, Ramsay Sedation Score were recorded every 5 min intraoperatively, in recovery, and 1, 2, 4, and 6 h postoperatively. Moreover, the Aldrete score was measured in recovery time for discharge from the recovery room.

Results

The mean age of participants was found to be 63.16 ± 6.07 years, and there was no statistically significant difference between the groups in terms of age, sex, and body mass index, SpO_2, and heart rate (P > 0.05). From 15 min after the start of surgery to 6 h postoperatively, the mean arterial pressure in the dexmedetomidine group was significantly lower than that in the other three groups, including ketamine, etomidate, and control (P < 0.05). The mean sedation score (Ramsay) during recovery and 1 h postoperatively was higher in the dexmedetomidine group compared with that in the control group, whereas the recovery time in the dexmedetomidine group was higher than that in the other groups (P < 0.001). In addition, the amount of propofol consumption in the two groups of dexmedetomidine and ketamine was significantly less than that in the etomidate and control groups (P < 0.001).

Conclusions

According to the results, dexmedetomidine caused better hemodynamic changes with more reduction in blood pressure and heart rate, and patients in the dexmedetomidine group did not require any specific medical treatment. Moreover, higher patient satisfaction and longer recovery duration were observed in the dexmedetomidine group than in the other study groups. As such, it is suggested that dexmedetomidine be used as an adjuvant in cataract surgery for more sedation, analgesia, and optimal intraoperative conditions.

Intravenous anesthesia with different doses of propofol combined with etomidate for painless colonoscopy in elderly obese patients: Effectiveness and impact on neurocognitive disorders

BACKGROUND

Painless colonoscopy in elderly obese patients is an invasive examination and requires good anesthesia and analgesia. Intravenous anesthesia with propofol combined with etomidate has good analgesic and sedative effects. However, there is no uniform standard for propofol dosage.

AIM

To investigate the effectiveness of intravenous anesthesia with different doses of propofol compounded with etomidate for painless colonoscopy in elderly obese patients and the effect on neurocognitive disorders.

METHODS

One hundred and twelve elderly obese patients who underwent painless colonoscopy at our hospital from January 2021 to March 2022 were selected and divided into either a control group or a study group (56 patients each) according to the odd-even nature of admission serial number. The control group (odd serial number) underwent intravenous anesthesia with a regular dose of propofol and etomidate for intravenous anesthesia, and the study group (even serial number) was given a small dose of propofol with etomidate for intravenous anesthesia. The anesthetic effect, time of colonoscopy, heart rate (HR) at different time points in the perioperative period, mean arterial pressure (MAP), incidence of adverse effects, use of anesthetic drugs, and cognitive function (Mini-mental State Examination [MMSE] score) before and after surgery were compared between the two groups.

RESULTS

There was no statistically significant difference in the onset of anesthesia, anesthesiologist's satisfaction with anesthesia, or colonoscopy time between the two groups, and the time to awakening and post-awakening observation room stay were significantly shorter in the study group than in the control group (P < 0.05). HR and MAP at T1 and T2 were lower than those at T0 in both groups (P < 0.05), and HR and MAP at all time points did not differ significantly between the two groups (P > 0.05). The dosage of propofol in the study group was significantly less than that of the control group (P < 0.05), though the dosage of etomidate and the number of propofol additions were not significantly different between the two groups. The incidence of adverse reactions in the study group (8.93%) was significantly lower than that in the control group (23.21%; P < 0.05). The postoperative 1-h MMSE score was lower than the preoperative score in both groups, but it was significantly higher in the study group than in the control group (P < 0.05).

CONCLUSION

The use of intravenous anesthesia with low-dose propofol with etomidate in painless colonoscopy in elderly obese patients can ensure the effectiveness of anesthesia, improve the quality of postoperative awakening, reduce adverse effects, and mitigate the impact on cognitive function.

Etomidate affects spatial learning and memory and neuronal apoptosis of rats via MAPK/ERK pathway

OBJECTIVE

To observe the effect of etomidate on spatial learning and memory and neuronal apoptosis in rats of different ages.

METHODS

The rats of different ages were divided into 3 age groups: juvenile (21-day old), adult (~3-months old) and elderly (~19-months old). Then, rats with similar age within a group were randomly divided into three subgroups, with 10 rats in each group. The experimental subgroups were intraperitoneally injected with etomidate (emulsion formulated, i.p. injection) at a dose of 5 mg/kg; the solvent control subgroups were given intraperitoneal injection of vehicle emulsion; and blank control subgroups received laparoscopic injection of normal saline. The rats' learning and memory ability was tested by Morris water maze. The tissue sections of each group's hippocampus were analyzed by H&E staining. The apoptosis of hippocampal cells was detected by TUNEL staining. MAPK expression in hippocampus was tested by Western blot.

RESULTS

Etomidate significantly extended the escape latency and reduced the platform crossings and the swimming time at original platform of juvenile rats, indicating that the spatial learning and memory function of juvenile rats can be affected by etomidate. However, etomidate had no effect on spatial learning and memory in adult and elderly rats. There were no obvious abnormalities in number of neurons and morphology of vertebral cells in the hippocampus of all experimental subgroups when compared with those of corresponding blank control subgroups. There was no statistically significant difference in apoptosis index of the hippocampal tissue between the experimental subgroups and corresponding blank control subgroups (P>0.05). Within juvenile group, the expression of p-ERK in the hippocampus of experimental subgroup was remarkably lower than that of solvent control subgroup and blank control subgroup (P<0.05), while there were no significant differences in p-p38 and p-JNK expressions among the three subgroups of juvenile rats (P>0.05). The expressions of p-ERK, p-p38 and p-JNK in adult and elderly rats were not affected by etomidate.

CONCLUSION

Etomidate may have certain effects on spatial learning and memory in juvenile rats but not in adult and elderly rats. Etomidate affects neither the number of neurons in the CA1 area of the hippocampus nor the morphology of vertebral cells and did not cause the apoptosis of nerve cells. The mechanism of etomidate influence on the spatial learning and memory function of young rats may connect with the inhibition of MAPK/ERK pathway.

Determination of the median effective dose of sufentanil for inhibiting the laryngeal mask insertion response in geriatric patients: a prospective, double-blinded, dose-response trial

Background

Laryngeal mask airway(LMA) have been widely used in clinical practice. Irritation to the patient during the insertion of a laryngeal mask can cause hemodynamic fluctuations, which is particularly unsafe for geriatric patients. We used probit regression analysis to determine the median effective dose of sufentanil to inhibit the response to LMA insertion in geriatric patients.

Methods

A total of 90 patients were selected for the study using the following inclusion criteria: age ≥ 65 years old, ASA grade I–III, and scheduled to undergo intravenous general anesthesia with LMA insertion. Each patient received a dose of sufentanil for anesthesia induction in one of six levels: 0.05, 0.1, 0.15, 0.2, 0.25, or 0.3 μg kg⁻¹. LMA insertion was scored with a 3-point, 6-category scale, with scores ≥ 16 indicating effective LMA insertion, and < 16 indicating ineffective LMA insertion. Mean arterial blood pressure (MAP), heart rate (HR), and bispectral index (BIS) were recorded 1 min before induction (T1), 1 min after induction (T2), 1 min after LMA insertion (T3), and 5 min after LMA insertion (T4) in each group. In addition, the plasma norepinephrine (NE) levels and adverse reactions were measured at T2 and T3 in each dosage group.

Results

Probit regression analysis showed that the ED50 of sufentanil inhibiting the response to LMA insertion in geriatric patients was 0.18 μg kg⁻¹ (95% CI: 0.16–0.21 μg kg⁻¹), and the ED95 was 0.31 μg kg⁻¹ (95% CI: 0.27–0.38 μg kg⁻¹), and the probit(p) = -2.34 + 12.90 × ln(Dose)(\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\chi^{2}$$\end{document}χ2 = 0.725, p = 0.948). Among all the patients, the number of effective LMA insertions was 57 (group A), and the number of ineffective LMA insertions was 33 (group B). The MAP, HR, and NE in group B were significantly higher than in group A at T3.

Conclusions

Sufentanil can effectively inhibit the patient’s response to LMA insertion, with stable hemodynamics and small stress response. The ED50 and ED95 were 0.18 μg kg⁻¹ (95% CI: 0.16–0.21 μg kg⁻¹) and 0.31 μg kg⁻¹(95% CI: 0.27–0.38 μg kg⁻¹), respectively.

Trial registration

This study was registered in the Chinese Clinical Trial Registry (Registration number: ChiCTR2100051827) on October 6, 2021.

The influence of anaesthetic choice on seizure duration of electroconvulsive therapy; etomidate versus methohexital

Background

Many of the anaesthetic drugs used for electroconvulsive therapy have anticonvulsant properties and may influence efficacy of electroconvulsive therapy. With this study we aim to provide more information on the effect of etomidate and methohexital on seizure duration. We explore the relationship between induction drug, motor and electroencephalography seizure duration. Moreover, we study the relationship of seizure duration and number of therapies.

Methods

In this retrospective study we collected data from patient records from 2005 until 2016. Inclusion criteria were the use of etomidate and/or methohexital and documentation of dosage, electroconvulsive therapy dosage and seizure duration. Exclusion criteria were missing data on either induction drug, dosage or seizure duration.

Results

Thirty seven patients were analysed. The mean age was 52 years and seventy six percent were female. Most patients were suffering from affective disorders (81%). Motor and electroencephalography seizure duration were analysed in 679 and 551 electroconvulsive therapies, respectively. Compared to methohexital, motor and electroencephalography seizures under etomidate were 7 and 13 s longer, respectively. Furthermore, there was a negative association between seizure duration and number of treatment and a negative association between seizure duration and electroconvulsive therapy dosage.

Conclusions

This study demonstrates significant longer motor and electroencephalography seizure duration using etomidate compared to methohexital. Etomidate might therefore increase the effectiveness of electroconvulsive therapy. Moreover, we observed a negative association between seizure duration, number of treatment and electroconvulsive therapy dosage. With this study we contribute to the available literature comparing methohexital and etomidate as induction agents for electroconvulsive therapy.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12871-022-01745-y.

The superiority of ketofol and etomidate against propofol or thiopental anesthesia for ECT

OBJECTIVES

Most anesthetic drugs used for electroconvulsive therapy (ECT) have dose-dependent anticonvulsive effects, counter-acting seizure induction, lowering seizure quality. However, a consummate drug for ECT anesthesia has not yet been established. Therefore, in this study, we aimed to investigate the effects of etomidate, thiopental, propofol and co-administration of ketamine-propofol (ketofol) on seizure quality and hemodynamic safety.

METHODS

Registries of 121 patients (1077 sessions) were retrospectively evaluated. The effects of anesthetics on ECT-related parameters (stimulation charge, central seizure duration, number of failed stimulation trials, mean arterial pressure, and peak heart rate) were analyzed via linear mixed-effects models.

RESULTS

Overall, the seizure duration decreased, and the stimulation charge increased in time with continuing sessions within a course of ECT. The decrease in seizure duration and the increase in required stimulation charge was significantly lower with etomidate and ketofol. Additionally, ketofol was significantly related to a lower number of failed stimulation trials compared to propofol. Ketofol and propofol use was associated with a significantly lower postictal mean arterial pressure.

CONCLUSION

Ketofol and etomidate were equivalently superior in the rate of decrease in seizure duration and the required elevation in stimulus charge, which would interpret into valuable clinical guidance, especially for "seizure resistant" patients, and their use may potentially lower ECT related cognitive side effects.

Effects of adding low-dose ketamine to etomidate on serum cortisol levels in critically ill cardiac patients: a randomized clinical trial

BACKGROUND

Etomidate was associated with an inhibition of adrenal steroid synthesis. This study aimed to evaluate the effects of adding low-dose ketamine to etomidate to minimize the decrease in serum cortisol level in critically ill cardiac patients.

METHODS

Sixty adult cardiac patients, ≥ 18 years, who underwent upper endoscopy and Colonoscopy to manage acute anemia in the cardiac intensive care units were enrolled. Patients were randomly divided into two groups: (group (E): n = 30) received etomidate 0.2 mg/kg IV followed by etomidate 0.05 mg/kg IV, and (group (KE): n = 30) received ketamine 0.5 mg/kg IV, then etomidate 0.1 mg/kg IV, followed by etomidate 0.05 mg/kg IV. The primary outcome was Serum cortisol level at 6 h after the procedure.

RESULTS

The mean postoperative cortisol level was significantly lower in group E (295.60 ± 49.218 nmol/L) versus group KE (461.00 ± 67.946 nmol/L), with 95% CI = 351.94 to 404.66; p = 0.000. In addition, the estimated serum cortisol reduction level was also significant between groups; In group E, the estimated cortisol level decreased nearly 53% from 632.40 ± 35.066 nmol/L to 295.60 ± 49.218 nmol/L 6 hours postoperative. While in group KE, the estimated cortisol level decreased only 27% from 639.13 ± 43.035 nmol/L to 461.00 ± 67.946 nmol/L.

CONCLUSIONS

Single-dose ketamine (0.5 mg/kg) was helpful to decrease the total dose of etomidate and hence decreased the percentage of serum cortisol level in such critically ill patients with preservation of patient satisfaction.

TRIAL REGISTRATION

This study is registered on ClinicalTrials.gov ( NCT04857450 ; principal investigator: Mostafa Mohammed Elsaid Elhamamsy; registration date: 23/04/ 2021).

A Comparative Study of the Effect of Anesthesia Induction with the Use of Four Drug Combinations Including "Propofol," "Etomidate-Propofol," "Thiopental," and "Midazolam-Thiopental" on Hemodynamic Changes during the Insertion of Laryngeal Mask in Eye Surgery

Background:

This study aimed to compare the efficacies of four anesthetic induction drugs (thiopental, propofol, midazolam-thiopental, and etomidate-propofol) on cardiovascular response during laryngeal mask airway (LMA) placement in eye surgery.

Materials and Methods:

The present clinical trial study included 128 patients who were candidates for ophthalmic surgery in four groups. Patients in the first group were given a combination of midazolam (0.04 mg/kg) with thiopental (2.5 mg/kg) (Group T + M). We administered propofol alone (2.5 mg/kg) to patients in the second group (Group P). The third group received a combination of etomidate (0.1 mg/kg) with propofol (1 mg/kg) (ET + P group) and patients in the fourth group received thiopental drug (5 mg/kg) alone (Group T). Then, the stability of patients' hemodynamic parameters before anesthesia was evaluated and compared immediately after anesthesia, 1, 3, and 5 min after LMA placement.

Results:

There was no significant difference between the four groups in changes in oxygen saturation level (P > 0.05). Furthermore, the difference between decreased systolic blood pressure and diastolic blood pressure over time was not significant in 5 min in both Groups T + M and T (P > 0.05). In addition, the stability of these two groups was higher than the other two groups (P < 0.05) and the most unstable group was Group P. The changes pulse ratein the P group were significant (P < 0.05).

Conclusion:

According to the results of the current study, thiopental and Midazolam can be used as an effective induction compound to facilitate LMA insertion with higher hemodynamic stability compared to propofol alone, propofol and etomidate, and thiopental alone.

Using Etomidate in a Two-month-old Infant with Cushing Syndrome due to Adrenocortical Carcinoma

Cushing syndrome (CS) is a rare disease caused by hypercortisolemia. Although surgical treatment is the first-line treatment in CS, the appropriate medication for the patient’s condition should be selected when medical treatment is needed. Etomidate is an adrenal-blocking drug used to treat CS and the most suitable for severe hypercortisolemia and adrenocortical carcinoma (ACC), due to cardiovascular stability and an anti-tumorigenic effect. However, its use and safe recommended dosage in infants with CS is unreported. Here we describe the case of a 2-month-old girl treated with etomidate for CS caused by ACC. Even though radical mass excision was performed, severe hypercortisolemia persisted, resulting from metastatic lesions in the liver, and medical treatment was considered. The etomidate doses, no bolus dose and infusion rate of 0.03 mg/kg/hour, may be an appropriate dose for severe hypercortisolemia in infants. This case will help determine future treatment strategies for similar cases in infants.

Endotracheal intubation sedation in the intensive care unit

Endotracheal intubation is one of the most common, yet most dangerous procedure performed in the intensive care unit (ICU). Complications of ICU intubations include severe hypotension, hypoxemia, and cardiac arrest. Multiple observational studies have evaluated risk factors associated with these complications. Among the risk factors identified, the choice of sedative agents administered, a modifiable risk factor, has been reported to affect these complications (hypotension). Propofol, etomidate, and ketamine or in combination with benzodiazepines and opioids are commonly used sedative agents administered for endotracheal intubation. Propofol demonstrates rapid onset and offset, however, has drawbacks of profound vasodilation and associated cardiac depression. Etomidate is commonly used in the critically ill population. However, it is known to cause reversible inhibition of 11 β-hydroxylase which suppresses the adrenal production of cortisol for at least 24 h. This added organ impairment with the use of etomidate has been a potential contributing factor for the associated increased morbidity and mortality observed with its use. Ketamine is known to provide analgesia with sedation and has minimal respiratory and cardiovascular effects. However, its use can lead to tachycardia and hypertension which may be deleterious in a patient with heart disease or cause unpleasant hallucinations. Moreover, unlike propofol or etomidate, ketamine requires organ dependent elimination by the liver and kidney which may be problematic in the critically ill. Lately, a combination of ketamine and propofol, “Ketofol”, has been increasingly used as it provides a balancing effect on hemodynamics without any of the side effects known to be associated with the parent drugs. Furthermore, the doses of both drugs are reduced. In situations where a difficult airway is anticipated, awake intubation with the help of a fiberoptic scope or video laryngoscope is considered. Dexmedetomidine is a commonly used sedative agent for these procedures.

Evolving Techniques in RSI: Can the Choice of Induction Agent Matter in Securing a Definitive Airway in Emergency Settings?

How to cite this article: George B, Joachim N. Evolving Techniques in RSI: Can the Choice of Induction Agent Matter in Securing a Definitive Airway in Emergency Settings? Indian J Crit Care Med 2022;26(1):15-17.

Etomidate versus ketamine for emergency endotracheal intubation: a randomized clinical trial

PURPOSE

Etomidate and ketamine are hemodynamically stable induction agents often used to sedate critically ill patients during emergency endotracheal intubation. In 2015, quality improvement data from our hospital suggested a survival benefit at Day 7 from avoidance of etomidate in critically ill patients during emergency intubation. In this clinical trial, we hypothesized that randomization to ketamine instead of etomidate would be associated with Day 7 survival after emergency endotracheal intubation.

METHODS

A prospective, randomized, open-label, parallel assignment, single-center clinical trial performed by an anesthesiology-based Airway Team under emergent circumstances at one high-volume medical center in the United States. 801 critically ill patients requiring emergency intubation were randomly assigned 1:1 by computer-generated, pre-randomized sealed envelopes to receive etomidate (0.2-0.3 mg/kg, n = 400) or ketamine (1-2 mg/kg, n = 401) for sedation prior to intubation. The pre-specified primary endpoint of the trial was Day 7 survival. Secondary endpoints included Day 28 survival.

RESULTS

Of the 801 enrolled patients, 396 were analyzed in the etomidate arm, and 395 in the ketamine arm. Day 7 survival was significantly lower in the etomidate arm than in the ketamine arm (77.3% versus 85.1%, difference - 7.8, 95% confidence interval - 13, - 2.4, p = 0.005). Day 28 survival rates for the two groups were not significantly different (etomidate 64.1%, ketamine 66.8%, difference - 2.7, 95% confidence interval - 9.3, 3.9, p = 0.294).

CONCLUSION

While the primary outcome of Day 7 survival was greater in patients randomized to ketamine, there was no significant difference in survival by Day 28.

Etomidate Compared to Ketamine for Induction during Rapid Sequence Intubation: A Systematic Review and Meta-analysis

AIMS AND OBJECTIVES

The objective of the study was to compare the safety and efficacy of etomidate and ketamine as induction agents for rapid sequence intubation (RSI) in acutely ill patients in emergency department and prehospital settings with respect to post-induction hypotension and first-pass intubation success during RSI.

MATERIALS AND METHODS

For this systematic review and meta-analysis, we searched PubMed, Embase, Cochrane, and ClinicalTrials.gov between database inception and June 1, 2021. Articles were included if they compared safety and efficacy of etomidate vs ketamine as induction agents, in patients undergoing RSI in emergency department and prehospital settings, without any restrictions on study design. The outcome measures were incidence of post-induction hypotension and first-pass intubation success. The dichotomous outcomes were assessed for odds ratio (OR) with 95% confidence interval (CI) using random-effects meta-analysis.

RESULTS

Of 87 records identified, 9 were eligible, all assessed as having a low to moderate risk of overall bias. Six studies, including 12,060 patients from prehospital emergency medical services, air medical transport, and emergency department settings, compared post-induction hypotension incidence between etomidate and ketamine groups. The meta-analysis showed that etomidate was associated with decreased risk of post-induction hypotension compared to ketamine (OR: 0.53; 95% CI: 0.31-0.91; I 2 = 68%). Seven studies, including 15,574 patients, reported on the rate of first-pass intubation success with etomidate vs ketamine. In the pooled analysis, no differences were seen in first-pass intubation success during RSI using etomidate vs ketamine as the induction agent (OR: 1.13; 95% CI: 0.95-1.36; I 2 = 16%).

CONCLUSION

The use of etomidate for induction during RSI is associated with a decreased risk of post-induction hypotension as compared to the use of ketamine, without an impact on the first-pass intubation success rate.

HOW TO CITE THIS ARTICLE

Sharda SC, Bhatia MS. Etomidate Compared to Ketamine for Induction during Rapid Sequence Intubation: A Systematic Review and Meta-analysis. Indian J Crit Care Med 2022;26(1):108-113.

Physical and Chemical Compatibility of Etomidate and Propofol Injectable Emulsions

INTRODUCTION

The mixture of etomidate and propofol is widely used in clinical practice to improve efficacy of general anesthesia and to minimize side effects. As a thermodynamically unstable system, emulsion is prone to destabilization through mechanisms including coalescence, flocculation, and creaming. Such unwanted phenomenon can induce fat embolism after intravenous administration. This study was aimed to investigate the physical and chemical stability of the mixture of etomidate and propofol in the dosage form of emulsion.

METHODS

This compatibility study focused on the critical quality attributes (CQAs) of drug-containing emulsions, such as appearance, pH, particle size and distribution, zeta potential, the observation under centrifugation, and drug content and impurity.

RESULTS

As the results, there were no significant changes in the CQAs of the mixed emulsions up to 24 h after mixing at refrigeration temperature (4°C), room temperature (25°C), and body temperature (37°C).

CONCLUSIONS

These results demonstrate that etomidate emulsion is physically and chemically compatible with propofol emulsions up to 24 h at 4°C, 25°C, and 37°C, suggesting that etomidate and propofol can be administrated in mixture without adversely affecting product characteristics, at least in vitro.

A Comparative Study of Valsalva Maneuver, Lidocaine, and Valsalva Maneuvers with Administration of Lidocaine to Reduce the Pain Associated with Administration of Etomidate During General Anesthesia

Objectives

The purpose of this study is a comparison of Valsalva, lidocaine, and Valsalva with administration of lidocaine to reduce the pain associated with administration of etomidate.

Methods

The present study is a clinical trial study. The number of samples in each group was 30 and a total of 90 people were selected. This study was a clinical trial and the subjects were randomly divided into three groups: Group 1: Valsalva, 2: Lidocaine, 3: Valsalva and Lidocaine. Pain due to etomidate was rated on a VAS from 1 (painless) to 3 (worst imaginable pain) and their information was recorded. The collected information was entered into SPSS 22 and analyzed with appropriate statistical tests.

Results

A total of 90 subjects participated in the present study and were divided into 3 groups: Valsalva, lidocaine, and Valsalva with lidocaine. No significant difference was observed between demographic variables in the study groups. There was a significant relationship between severity of pain in the three groups. According to the results, the highest pain intensity was in the Valsalva group and the lowest pain intensity was in the Valsalva with lidocaine group.

Conclusions

Valsalva with lidocaine reduces the severity of pain caused by etomidate to a greater extent than other groups.

Etomidate ameliorated advanced glycation end-products (AGEs)-induced reduction of extracellular matrix genes expression in chondrocytes

Osteoarthritis (OA) is a rheumatic disease common in the elderly. AGEs are the end products of glycation reactions and play an important role in the development of OA. Etomidate is a general anesthesia-inducing agent recently reported to exert significant anti-inflammatory effects. The present study aims to explore the protective effect of Etomidate against advanced glycation end-products (AGEs)-induced reduction of extracellular matrix gene expression in chondrocytes. In the present study, we found that AGEs significantly reduced the expression of Collagen II (COL2A1) and Aggrecan (ACAN) at the gene level. Furthermore, AGEs inhibited the expression of SRY-related high mobility group-box gene 9 (SOX-9), promoting the expression of COL2A1 and ACAN. COL2A1, ACAN, and SOX-9 in chondrocytes were significantly elevated by treatment with Etomidate alone. Consistently, Etomidate ameliorated AGEs-induced downregulation of COL2A1, ACAN, and SOX-9 in a dose-dependent manner. Importantly, we found that knockdown of SOX-9 eliminated the beneficial effects of Etomidate against AGEs-induced decrease in COL2A1 and ACAN genes. Based on these findings, we demonstrated that Etomidate could ameliorate AGEs-induced reduction of extracellular matrix gene expression in chondrocytes by upregulating SOX-9.

Application of etomidate and propofol mixture in hematoma removal in patients with intracranial epidural hematoma

OBJECTIVE

To innvestigate the application of etomidate and propofol mixture in the evacuation of hematoma in patients with epidural hematoma.

METHODS

98 patients with epidural hematoma were randomly divided into two groups: the joint group (n=49, anesthesia induction with etomidate and propofol) and the etomidate group (n=49, anesthesia induction with etomidate) using a random number table. Hemodynamics, stress response and cerebral oxygen metabolism were compared between the two groups at T0 (pre-anesthesia induction), T1 (after endotracheal intubation), T2 (10 min after the beginning of the operation) and T3 (the end of the operation). Adverse reactions were also analyzed.

RESULTS

Compared with T0, the mean arterial pressure (MAP) at T1, T2 and T3 in the joint group decreased first and then increased, and the MAP at T1 was significantly lower than that in the etomidate group (P<0.05). Compared with T0, blood oxygen saturation of internal jugular vein bulb (SjvO₂) increased in T1-T3 groups, and SjvO₂ in the joint group was higher than that in the etomidate group (all P<0.05). Compared with T0, cerebral oxygen uptake rate (CERO₂) in the T1-T3 groups decreased significantly, and CERO₂ at T3 in the joint group was higher than that in the etomidate group (all P<0.05). Compared with T0, the levels of cortisol and superoxide dismutase (SOD) at T3 in the two groups were significantly lower, but those in the etomidate group were higher than those in the combination group (all P<0.05). There was no significant difference in the incidence of postoperative anesthesia-related adverse reactions between the two groups (P>0.05).

CONCLUSION

Etomidate has less effect on hemodynamics and stress reaction during intravenous anesthesia, but its combination with propofol can improve cerebral oxygen metabolism to a certain extent with fewer adverse reactions.

Optimization, and in vitro and in vivo evaluation of etomidate intravenous lipid emulsion

The aim of this investigation was to develop an etomidate intravenous lipid emulsion (ETM-ILE) and evaluate its properties in vitro and in vivo. Etomidate (ETM) is a hydrophobic drug, and organic solvents must be added to an etomidate injectable solution (ETM-SOL) to aid dissolution, that causes various adverse reactions on injection. Lipid emulsions are a novel drug formulation that can improve drug loading and reduce adverse reactions. ETM-ILE was prepared using high-pressure homogenization. Univariate experiments were performed to select key conditions and variables. The proportion of oil, egg lecithin, and poloxamer 188 (F68) served as variables for the optimization of the ETM-ILE formulation by central composite design response surface methodology. The optimized formulation had the following characteristics: particle size, 168.0 ± 0.3 nm; polydispersity index, 0.108 ± 0.028; zeta potential, −36.4 ± 0.2 mV; drug loading, 2.00 ± 0.01 mg/mL; encapsulation efficiency, 97.65% ± 0.16%; osmotic pressure, 292 ± 2 mOsmol/kg and pH value, 7.63 ± 0.07. Transmission electron microscopy images showed that the particles were spherical or spheroidal, with a diameter of approximately 200 nm. The stability study suggested that ETM-ILE could store at 4 ± 2 °C or 25 ± 2 °C for 12 months. Safety tests showed that ETM-ILE did not cause hemolysis or serious vascular irritation. The results of the pharmacokinetic study found that ETM-ILE was bioequivalent to ETM-SOL. However, a higher concentration of ETM was attained in the liver, spleen, and lungs after administration of ETM-ILE than after administration of ETM-SOL. This study found that ETM-ILE had great potential for clinical applications.

Comparison of the effects of etomidate, ketamine, sodium thiopental, and midazolam on the mortality of patients with COVID-19 requiring intubation

Background: Among the medications administered for the management of COVID-19 patients, the induction drugs used for intubation have received little attention. The aim of this study was to compare the effect of induction drugs on the mortality of patients with COVID-19 requiring intubation.

Methods: In this retrospective study, all patients who were admitted to Shahid Sadoughi and Shahid Rahnemoun hospitals in Yazd from February to March 2020 with definitive diagnosis of COVID-19 and needed intubation were enrolled. Patients were divided into 4 groups based on the type of drugs used in intubation, and mortality rate was assessed at the end of the first, second, fourth, and seventh days of the study. Statistical analyses were performed using SPSS 20 and P values <.05 was considered significant.

Results: In this study, 76 patients were examined. Patients were divided into 4 groups, of which 21 were in etomidate group, 8 in ketamine group, 21 in sodium thiopental group, and 35 in midazolam group. Mortality rate in these 4 groups was 25%, 12.5%, 14.3%, and 14.3% (p=0.822), respectively at the end of the first day after intubation; it was 83.3%, 12.5%, 28.6%, and 25.7% (p=0.001), respectively, at the end of the second day; it was 83.3%, 12.5%, 42.9%, and 42.9% (p=0.015), respectively, until the end of the fourth day; it was 100%, 25%, 61.9%, and 65.7% (p=0.007), respectively, until the end of the seventh day. Admission to intubation time interval was 0.91±0.99, 3.12±1.95, 4.09±2.44, and 4.74±2.62 days, respectively (p<0.001).

Conclusion: The results of this study suggest that the use of etomidate may be associated with higher mortality in COVID-19 patients. Further studies are needed to verify the results of this study.

Electroencephalographic dynamics of etomidate-induced loss of consciousness

BACKGROUND

Highly structured electroencephalography (EEG) oscillations can occur in adults during etomidate-induced general anesthesia, but the link between these two phenomena is poorly understood. Therefore, in the present study, we investigated the electroencephalogram dynamics of etomidate-induced loss of consciousness (LOC) in order to understand the neurological mechanism of etomidate-induced LOC.

METHODS

This study is a prospective observational study. Etomidate-induced anesthesia was performed on eligible patients undergoing elective surgery. We analyzed EEG data from 20 patients who received etomidate for the induction of general anesthesia. We used power spectra and coherence methods to process and analyze the EEG data. Our study was based on 4-channel EEG recordings.

RESULTS

Compared with the baseline (awake period), etomidate induced an increase in power in delta, theta, alpha and beta waves during LOC. Compared with the awake period, the delta-wave (1-4 Hz), alpha-wave(8-13 Hz), and theta-wave(4-8 Hz) coherence increased significantly during LOC, while the slow-wave (< 1 Hz) coherence decreased. However, the delta wave (1.0-4.0 Hz) during etomidate-induced LOC was more coherent than during the awake period (1.86-3.17 Hz, two-group test for coherence, p < 0.001).

CONCLUSIONS

The neural circuit mechanism of etomidate-induced LOC is closely related to the induction of oscillation in delta, theta, alpha and beta waves and the enhancement of delta-wave coherence.

TRIAL REGISTRATION

ChiCTR1800017110.

Comparison of the influence of low dose etomidate and propofol as priming dose on the incidence of etomidate induced myoclonus: a randomised, double-blind clinical trial

Background

Though hemodynamically stable, etomidate is known for its myoclonus side effect following induction. The main aim of this study is an effective attempt to decrease the incidence of myoclonus with a priming agent.

Methods

A prospective, double-blind study was carried out on 50 adults posted for elective surgery. After premedication, priming was done with etomidate 0.03 mg.kg^-1 (Group E) and propofol 0.2 mg.kg^-1 (Group P), i.e., 1/10th of induction dose. After 60 seconds of priming, patients were induced with etomidate by titrating dose over 60 seconds until loss of verbal command and eyelash reflex. The grading of myoclonus, induction dosage, and hemodynamics for 10 minutes post induction were recorded.

Results

In the study, only 4 cases had myoclonus. Grade 1 myoclonus was encountered in three cases of etomidate group, while only one case in the propofol group had grade 2 myoclonus which was not statistically significant (p-value: 0.12). There was a significant reduction in the etomidate induction dosage in both groups.

Conclusion

Priming with etomidate and propofol is equally effective in reducing myoclonus with the added benefit of hemodynamic stability and reduction of an induction dose of etomidate (> 50%).

Histopathological study on neuroapoptotic alterations induced by etomidate in rat hippocampus

In human, there is substantial neurogenesis in the hippocampus that is implicated in memory formation and learning. These new-born neurons can be affected by neuropathological conditions. Anesthesia and surgical procedures are associated with postoperative cognitive changes particularly, impaired memory and learning. Therefore, the aim of this study was to evaluate the possible neurodegenerative effects of etomidate in rat hippocampus. Thirty male Wistar rats weighing 250 ± 30 g were randomly divided into 3 groups: 1) Etomidate group; four times 20 mg intraperitoneal injection with 1-h intervals, 2) Control group; the equal volume of normal saline, and 3) Normal group; without any intervention. 6 h after the last injection, the brains were removed and processed according to routine histological methods. TUNEL assay and toluidine blue staining were performed to evaluate neuro-histopathological changes in different regions of hippocampus. Our results showed that the number of TUNEL positive cells and dark neurons (DNs) in etomidate group were significantly higher in the CA1, CA2, CA3, and dentate gyrus (DG) of hippocampus compared with the control and normal groups (p < 0.05). While, there was no significant difference between the various regions of hippocampus in control and normal groups. Our findings showed that etomidate can increase apoptotic cells and dark neurons induction in different regions of hippocampus mainly in DG.

Effect of Pre-Treatment with a Combination of Fentanyl and Midazolam for Prevention of Etomidate-Induced Myoclonus

Objective

Pre-treatment with either fentanyl or midazolam has previously been used to prevent etomidate-induced myoclonus (EIM). The aim of the present study was to determine the effect of pre-treatment with a combination of midazolam and fentanyl in reducing the incidence and severity of EIM.

Methods

This prospective, randomised, double-blind study was conducted on 210 surgical patients allocated to three study groups. Group F patients received fentanyl 2 μg kg^-1 and 5 mL saline. Group M patients received midazolam 0.03 mg kg^-1 and 5 mL saline. Group FM patients received fentanyl 2 μg kg^-1 plus midazolam 0.03 mg kg^-1. The study drugs were administered intravenously over 30 s. Five minutes after study drug administration, etomidate 0.3 mg kg^-1 was administered over 60 s. Patients were observed for 1 min for occurrence and severity of EIM.

Results

The incidence of EIM was 34/70 (48.6%), 55/70 (78.6%) and 11/70 (15.7%) in groups F, M and FM, respectively (p=0.001). Myoclonus of moderate or severe grade occurred in 23/70 (32.9%), 45/70 (64.3%) and 6/70 (8.6%) in groups F, M and FM, respectively (p=0.001). Patients who experienced myoclonus exhibited a significantly higher percentage change in post-induction heart rate (p=0.02), systolic blood pressure (p=0.001) and mean blood pressure (p=0.001) from pre-induction values than those who did not.

Conclusion

Pre-treatment with a combination of fentanyl and midazolam is more effective than that with fentanyl or midazolam alone in reducing the incidence and severity of EIM. Myoclonus is associated with a higher post-induction haemodynamic variation.