Etomidate revisited

Effectiveness of sodium thiopentone, propofol, and etomidate as an ideal intravenous anesthetic agent for modified electroconvulsive therapy

Introduction:

Electroconvulsive therapy (ECT) is a well-established psychiatric treatment in which seizures are electrically induced in patients for therapeutic effects. ECT can produce severe disturbances in the cardiovascular system and a marked increase in cerebral blood flow and intracranial pressure. These cardiovascular changes may be altered using various anesthetic drugs.

Aim and Objectives:

This study was undertaken to compare the effects of intravenous (IV) sodium thiopentone, propofol, and etomidate, used as IV anesthetic agents in modified ECT as regards, induction time and quality of anesthesia, alteration of hemodynamics, seizure duration, and recovery time.

Materials and Methods:

A total of 90 patients in the age group of 16–60 years of either sex, who had to undergo ECT therapy were divided randomly into three equal groups. Group A received propofol 1% - 1.5 mg/Kg, Group B received etomidate - 0.2 mg/Kg, and Group C received thiopentone 2.5% - 5 mg/Kg. All the patients were monitored for changes in heart rate, systolic blood pressure, diastolic blood pressure, and oxygen saturation at basal, after induction and 1 min, 2 min, 3 min, 5 min, 10 min, 20 min, and 30 min following ECT. Quality of anesthesia, seizure duration, and recovery times were also recorded.

Conclusion:

We found that propofol had the advantage of smooth induction, stable hemodynamic parameters and rapid recovery as compared to etomidate and thiopentone. Thiopentone had the advantage over propofol of having longer seizure duration at the cost of a relatively prolonged recovery period. Etomidate had a definite advantage of longer seizure duration.

Effect of electroacupuncture at Zusanli (ST36) and Sanyinjiao (SP6) acupoints on adrenocortical function in etomidate anesthesia patients

Background

We aimed to investigate the effect of electroacupuncture at Zusanli (ST36) and Sanyinjiao (SP6) on adrenocortical function in patients with etomidate anesthesia.

Material/Methods

We randomly divided 80 patients who underwent elective surgery into 4 groups: group etomidate (ETO), group etomidate + electroacupuncture (ETO+EA), group etomidate + sham acupuncture (ETO+SEA), and group propofol (PRO). The patients in group ETO, ETO+EA, and ETO+SEA were induced with etomidate and sufentanil and maintained with intravenous infusion of etomidate and remifentanil. Group PRO was induced with propofol and sufentanil and maintained with propofol and remifentanil. Group ETO+EA received electro-acupuncture stimulation at Zusanli and Sanyinjiao throughout the operation, while group ETO+SEA received electro-acupuncture stimulation at non-acupoints. We recorded the values of MAP, HR, BIS, CVP, cortisol, ACTH, epinephrine, norepinephrine, and arterial blood gas during the perioperative period.

Results

Cortisol concentrations were significantly higher at all times except T0 in group ETO+EA compared with group ETO. The ACTH concentrations were lower in group ETO+EA than that in group ETO at point T3.

Conclusions

Electroacupuncture at ST 36 and SP 6 can mitigate the adrenal cortical inhibition induced by etomidate and can reduce the secretion of catecholamines during surgery.

Comparison of anesthetics in electroconvulsive therapy: an effective treatment with the use of propofol, etomidate, and thiopental

OBJECTIVES

Electroconvulsive therapy (ECT) is considered to be one of the most effective treatments in psychiatry. Currently, three medications for anesthesia are used routinely during ECT: propofol, etomidate, and thiopental. The objective of this study was to evaluate the effects of the anesthetics used in ECT on seizure threshold and duration, hemodynamics, recovery from ECT, and immediate side effects.

METHODS

Our study is a retrospective cohort study, in which a comparison was made between three groups of patients who underwent ECT and were anesthetized with propofol, etomidate, or thiopental. The main effect compared was treatment dose and seizure duration. All patients were chosen as responders to ECT.

RESULTS

Data were gathered about 91 patients (39 were anesthetized with thiopental, 29 with etomidate, and 23 with propofol). Patients in the thiopental group received a lower electrical dose compared to the propofol and etomidate group (mean of 459 mC compared to 807 mC and 701 mC, respectively, P<0.001). Motor seizure duration was longer in the thiopental group compared to propofol and etomidate (mean of 40 seconds compared to 21 seconds and 23 seconds, respectively, P=0.018). Seizure duration recorded by electroencephalography was similar in the thiopental and etomidate groups and lower in the propofol group (mean of 57 seconds in both groups compared to 45 seconds, respectively, P=0.038).

CONCLUSION

Patients who were anesthetized with thiopental received a lower electrical treatment dose without an unwanted decrease in seizure duration. Thiopental might be the anesthetic of choice when it is congruent with other medical considerations.

Comparison of effects of fentanyl and remifentanil on hemodynamic response to endotracheal intubation and myoclonus in elderly patients with etomidate induction

BACKGROUND

Etomidate has a stable hemodynamic profile after induction, but hypertension and tachycardia are frequent after intubation as well as myoclonus. We compared the effects of fentanyl and remifentanil on the hemodynamic response to intubation and myoclonus during etomidate induction in elderly patients.

METHODS

Ninety ASA I or II patients aged over 65 were randomly assigned to 3 groups. Group C received normal saline 10 ml (n = 30), group F and R were pretreated with fentanyl 1.0 µg/kg (n = 30) or remifentanil 1.0 µg/kg with continuous infusion of 0.1 µg/kg/min (n = 30) 1 min before induction with etomidate 0.2 mg/kg. Endotracheal intubation was performed after administration of rocuronium 0.8 mg/kg. Systolic blood pressure (SBP), mean arterial pressure, diastolic blood pressure (DBP), heart rate (HR), and the incidence and intensity of myoclonus were recorded.

RESULTS

After intubation, group R showed significant decreases compared with groups C and F for all of the hemodynamic variables measured. The incidences of increases in SBP and HR of more than 30% of the baseline levels, SBP of > 200 mmHg, and HR of > 120 beats/min were significantly lower in group R (0%, 10%, 0%, and 0%, respectively) compared with groups C (83%, 83%, 30%, and 13%, respectively) and F (63%, 77%, 13%, and 7%, respectively). The frequency and intensity of myoclonus were significantly decreased in both groups F and R compared with group C.

CONCLUSIONS

Pretreatment with remifentanil suppressed cardiovascular reactions to endotracheal intubation more effectively than that of fentanyl during etomidate induction. Both opioids reduced the incidence of myoclonus.

Comparison between the Effects of Propofol and Etomidate on Motor and Electroencephalogram Seizure Duration during Electroconvulsive Therapy

An ideal anaesthetic for electroconvulsive therapy (ECT) should have rapid onset and offset with no effect on seizure duration, and provide cardiovascular stability during the procedure. Propofol is commonly used, even though it has been shown to shorten seizure duration which might affect the efficacy of ECT. Etomidate has been advocated as an alternative. This prospective, randomised, single-blind, crossover study was conducted to compare the effects of etomidate (Etomidate-®Lipuro, B. Braun Ltd, Melsungen, Germany) and propofol (Diprivan®, AstraZeneca, UK) on seizure duration as well as haemodynamic parameters in patients undergoing ECT. Twenty patients aged between 18 and 70 years were recruited. Group I received etomidate 0.3 mg/kg for the first course of ECT (Group IA) and propofol 1.5 mg/kg for the second ECT (Group IB), while Group II received propofol for the first ECT (Group IIA) and etomidate for the second ECT (Group IIB). There was a washout period of two to three days in between procedures. Parameters recorded included motor seizure duration, electroencephalogram seizure duration, blood pressure and heart rate. Analysis demonstrated neither period effect nor treatment period interaction. Etomidate was associated with a significantly longer motor and electroencephalogram seizure duration compared with propofol (P <0.01). Neither drug demonstrated consistent effects in suppressing the rise in heart rate or blood pressure during ECT. Myoclonus and pain on injection were the most common adverse effects in etomidate group and propofol group respectively. Etomidate is a useful anaesthetic agent for ECT and should be considered in patients with inadequate seizure duration with propofol.

A novel use of etomidate for intentional adrenal suppression to control severe hypercortisolemia in childhood

OBJECTIVE

To describe a novel use for etomidate in critically ill children. Etomidate induction of anesthesia in children is controversial due to adrenal suppression; we review this controversy and describe a therapeutic application of this "side effect" using a continuous etomidate infusion in pediatric intensive care to deliberately suppress critically elevated endogenous cortisol.

DESIGN

Case report.

SETTING

A tertiary pediatric intensive care unit.

PATIENT

A 6-year-old boy with severe, life-threatening hypercortisolemia secondary to Cushing's disease.

INTERVENTIONS

Admission to pediatric intensive care unit, before bilateral adrenalectomies, to facilitate etomidate infusion to reduce endogenous hypercortisolemia, as first-line treatment with metyrapone and ketoconazole had failed.

MEASUREMENT AND MAIN RESULTS

Continuous intravenous etomidate at 0.08 mg/kg/hr decreased serum cortisol from 1200 to 250 nmol/L within 48 hours. Once etomidate and hydrocortisone therapy provided stable serum cortisol levels, bilateral laparoscopic adrenalectomies were undertaken. A perioperative cortisol surge was seen, but to a much lower peak than expected without prior etomidate suppression.

CONCLUSIONS

The adrenal suppression caused by etomidate, so controversial in the care of the critically ill at present, can be therapeutically used for short-term control of severe hypercortisolemia in children.

Remifentanil and etomidate for laryngeal mask airway insertion

Etomidate does not depress the upper airway reflexes, making it difficult to insert a laryngeal mask airway (LMA) when using it for anaesthesia. This study investigated the effect of adding remifentanil to etomidate for LMA insertion. Fifty adult patients, undergoing cystoscopy, were randomized to two groups. The propofol-remifentanil group (n=25) received propofol anaesthesia induction (2.5 mg/kg) and a remifentanil bolus of 0.5 microg/kg, followed by a 2-min remifentanil infusion of 0.05 microg/kg per min. The etomidate-remifentanil group (n=25) received etomidate anaesthesia induction (0.3 mg/kg) and remifentanil as described. The LMA was inserted by a blinded anaesthetist who assessed a number of parameters. Only 13 LMAs were inserted at the first attempt in the etomidate-remifentanil group compared with 23 in the propofol-remifentanil group. Gagging, chest rigidity and myoclonus occurred significantly more frequently in the etomidate-remifentanil group. We conclude that the addition of remifentanil to etomidate anaesthesia induction does not improve LMA insertion.