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

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

Background

Etomidate has been observed to precipitate myoclonus in patients undergoing induction of general anaesthesia. This study was designed to investigate the effect of pretreatment with a small dose of esketamine on the incidence of myoclonus induced by etomidate.

Methods

One hundred adult patients, who were scheduled to undergo selective operations with general anesthesia, were randomly divided into two groups, with one group receiving esketamine (Group E) and the other receiving normal saline (Group C). The group receiving esketamine (Group E) was administered an injection of 0.15 mg/kg of esketamine, while the control group (Group C) was given an equivalent volume of normal saline two minutes before the administration of 0.3 mg/kg of etomidate. The primary objective was to determine the incidence of etomidate-induced myoclonus. Secondary endpoints included the severity of etomidate-induced myoclonus and changes in haemodynamic variables at various time intervals. Additionally, the incidence of adverse effects such as dizziness, bradycardia, hypotension and hallucination were recorded from the administration of esketamine or normal saline to the injection of etomidate.

Results

The incidence of myoclonus was significantly lower in Group E (20%) than in Group C (62%). Compared with the control group, the esketamine group also experienced a reduction in the moderate and severe of myoclonus. However, there was no statistically significant difference between the two groups for mild etomidate-induced myoclonus. The haemodynamic data (mean arterial pressure and heart rate) showed no statistically significant differences between two groups at the three time points. The incidence of dizziness, bradycardia, hypotension and hallucination was similar in both groups.

Conclusion

Pretreatment with 0.15 mg/kg esketamine prior to anaesthesia induction with etomidate was observed to markedly reduce the incidence and severity of myoclonus, while having no effect on mild etomidate-induced myoclonus and maintaining a stable haemodynamic status.

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

Background and Aims

Etomidate is a popular induction agent, but its use is associated with myoclonus in 50%-80% of non-premedicated patients. This study aims to compare dexmedetomidine and butorphanol for their relative efficacy in preventing etomidate-induced myoclonus.

Methods

This randomised study was conducted after obtaining institutional ethical committee clearance and written informed consent from sixty American Society of Anesthesiologists (ASA) I or II consenting patients between 18 and 60 years of age of either sex who had been scheduled for elective surgeries under general anaesthesia. Patients were randomly allocated to dexmedetomidine 0.5 μg/kg (Group D) or butorphanol 0.015 mg/kg (Group B). Both the drugs were given as an infusion over a period of 10 min before induction of anaesthesia. The primary outcome was the incidence of myoclonic movements after etomidate, and the secondary outcomes were the severity of myoclonus, changes in the haemodynamic parameters and incidence of airway complications. Normally distributed variables were compared using Student's t-test, and non-normally distributed variables were compared using Mann-Whitney U test. Qualitative data were analysed using Chi-square/Fisher's exact test. A P-value <0.05 was considered significant.

Results

The incidence of etomidate-induced myoclonus was significantly higher in group B compared to group D (P = 0.035). The median (interquartile range [IQR]) of myoclonus grade in patients of group D was 0.00 (0.00-3.00), and group B was 2.50 (0.00-3.00) (P = 0.035). Haemodynamics and airway-related complications were comparable between the groups.

Conclusion

Dexmedetomidine was more effective than butorphanol in preventing etomidate-induced myoclonus.

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.

Etomidate-Induced Myoclonus in Sprague-Dawley Rats Involves Neocortical Glutamate Accumulation and N -Methyl- d -Aspartate Receptor Activity

BACKGROUND

Etomidate-induced myoclonus, a seizure-like movement, is of interest to anesthetists. However, its origin in the brain and its underlying mechanism remain unclear.

METHODS

Adult male Sprague-Dawley rats were anesthetized with etomidate, propofol, or lidocaine plus etomidate. We assessed the incidence of myoclonus, behavioral scores, and levels of glutamate and γ-aminobutyric acid (GABA) in the neocortex and hippocampus. To determine the origin and how N -methyl- d -aspartate receptors (NMDARs) modulate etomidate-induced neuroexcitability, the local field potential and muscular tension were monitored. Calcium imaging in vitro and immunoblotting in vivo were conducted to investigate the mechanisms underlying myoclonus.

RESULTS

The incidence of etomidate (1.5 mg/kg in vivo)-induced myoclonus was higher than that of propofol (90% vs 10%, P = .0010) and lidocaine plus etomidate (90% vs 20%, P = .0050). Etomidate at doses of 3.75 and 6 mg/kg decreased the mean behavioral score at 1 (mean difference [MD]: 1.80, 95% confidence interval [CI], 0.58-3.02; P = .0058 for both), 2 (MD: 1.60, 95% CI, 0.43-2.77; P = .0084 and MD: 1.70, 95% CI, 0.54-2.86; P = .0060), 3 (MD: 1.60, 95% CI, 0.35-2.85; P = .0127 and MD: 1.70, 95% CI, 0.46-2.94; P = .0091) minutes after administration compared to etomidate at a dose of 1.5 mg/kg. In addition, 0.5 and 1 µM etomidate in vitro increased neocortical intracellular calcium signaling; this signaling decreased when the concentration increased to 5 and 10 μM. Etomidate increased the glutamate level compared to propofol (mean rank difference: 18.20; P = .003), and lidocaine plus etomidate (mean rank difference: 21.70; P = .0002). Etomidate in vivo activated neocortical ripple waves and was positively correlated with muscular tension amplitude (Spearman's r = 0.785, P < .0001). Etomidate at 1.5 mg/kg decreased the K-Cl cotransporter isoform 2 (KCC2) level compared with propofol (MD: -1.15, 95% CI, -1.47 to -0.83; P < .0001) and lidocaine plus etomidate (MD: -0.64, 95% CI, -0.96 to -0.32; P = .0002), DL-2-amino-5-phosphopentanoic acid (AP5) suppressed these effects, while NMDA enhanced them.

CONCLUSIONS

Etomidate-induced myoclonus or neuroexcitability is concentration dependent. Etomidate-induced myoclonus originates in the neocortex. The underlying mechanism involves neocortical glutamate accumulation and NMDAR modulation and myoclonus correlates with NMDAR-induced downregulation of KCC2 protein expression.

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

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

Effects of etomidate combined with dexmedetomidine on adrenocortical function in elderly patients: a double-blind randomized controlled trial

Etomidate has been advocated to be used in anesthesia for the elderly and the critically ill patients due to its faint effect on cardiovascular system. But the dose-dependent suppression of etomidate on adrenal cortex function leads to the limitation of its clinical application. Clinical research showed that dexmedetomidine could reduce the dose requirements for intravenous or inhalation anesthetics and opioids, and the hemodynamics was more stable during the operation. The objective was to observe the effect of etomidate combined with dexmedetomidine on adrenocortical function in elderly patients. 180 elderly patients scheduled for elective ureteroscopic holmium laser lithotripsy were randomly allocated to PR group anesthetized with propofol-remifentanil, ER group anesthetized with etomidate-remifentanil, and ERD group anesthetized with dexmedetomidine combined with etomidate-remifentanil. Patients in each group whose operation time was less than or equal to 1 h were incorporated into short time surgery group (PR₁ group, ER₁ group and ERD₁ group), and whose surgical procedure time was more than 1 h were incorporated into long time surgery group (PR₂ group, ER₂ group and ERD₂ group). The primary outcome was the serum cortisol and ACTH concentration. The secondary outcomes were the values of SBP, DBP, HR and SpO₂, the time of surgical procedure, the dosage of etomidate and remifentanil administered during surgery, the time to spontaneous respiration, recovery and extubation, and the duration of stay in the PACU. The Serum cortisol concentration was higher at t_1~2   in ERD₁ group compared to ER₁ group (P < 0.05). The Serum cortisol concentration at t_1~3   was higher in ERD₂ group than in ER₂ group (P < 0.05). The Serum ACTH concentration was lower at t_1~2  in ERD₁ group compared to ER₁ group (P < 0.05). The Serum ACTH concentration at t_1~3  was lower in ERD₂ group compared to ER₂ group (P < 0.05). The SBP at T₁ and T₃ were higher in ER₂ and ERD₂ group than in PR₂ group (P < 0.05). The DBP in ER₁ and ERD₁ group were higher at T₁ compared to PR₁ group (P < 0.05). The dosage of etomidate was significantly lower in ERD₁ group and ERD₂ group than in ER₁ group and ER₂ group (P < 0.05), respectively. The administration of dexmedetomidine combined with etomidate can attenuate the inhibition of etomidate on adrenocortical function in elderly patients and maintain intraoperative hemodynamic stability.