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

BACKGROUND: Etomidate injection is often associated with myoclonus. Etomidate injection technique influences the incidence of myoclonus. This study was designed to clarify which of the two injection techniques—slow injection or priming with etomidate—is more effective in reducing myoclonus. METHODS: This prospective randomized controlled study was conducted on 189 surgical patients allocated to three study groups. Control group (Group C, n = 63) received 0.3 mg/kg etomidate (induction dose) over 20 s. Priming group (Group P, n = 63) received pretreatment with 0.03 mg/kg etomidate, followed after 1 min by an etomidate induction dose over 20 s. Slow injection group (Group S, n = 63) received etomidate (2 mg/ml) induction dose over 2 min. The patients were observed for occurrence and severity of myoclonus for 3 min from the start of injection of the induction dose. RESULTS: The incidence of myoclonus in Group P (38/63 [60.3%], 95% CI: 48.0–71.5) was significantly lower than in Group C (53/63 [84.1%], 95% CI: 72.9–91.3, P = 0.003) and Group S (49/63 [77.8%], 95% CI: 66.0–86.4, P = 0.034). Myoclonus of moderate or severe grade occurred in significantly more patients in Group C (68.3%) than in Group P (36.5%, P < 0.001) and Group S (50.8%, P = 0.046), but the difference between Groups P and S was not significant (P = 0.106). CONCLUSIONS: Priming is more effective than slow injection in reducing the incidence of myoclonus, but their effects on the severity of myoclonus are comparable.
Etomidate ; Humans ; Incidence ; Myoclonus* ; Prospective Studies

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

BACKGROUND: Etomidate frequently causes myoclonus. Since the myoclonus is caused by a transient disequilibrium due to etomidate exposure in the CNS, we hypothesized that a slow rate of injection of the drug may decrease the incidence of myoclonus. We conducted a prospective randomized study to compare the effect of two different types of the etomidate injection rate on the incidence and severity of myoclonus. METHODS: Fifty patients were randomly assigned to the fast-injection group (group F) or slow-injection group (group S): Group F patients received etomidate (0.3 mg/kg) over ten seconds. The same dose was administered over two minutes for group S patients. The response to the injection of etomidate was graded on a four-point scale in a blinded manner. The time to loss of consciousness (LOC) was also recorded. RESULTS: The incidence of myoclonus was significantly lower (P < 0.001) in group S patients; 84% and 28% in group F and group S patients, respectively. The myoclonus was also significantly less severe in group S patients (P < 0.001). The time to LOC was significantly longer in group S patients (106 +/- 22 sec) than that of group F patients (49 +/- 18 sec, P < 0.001). CONCLUSIONS: With same dose, a slower rate of injection resulted in a lower incidence of myoclonus and can effectively reduce myoclonus without the use of a pretreatment agent.
Etomidate ; Humans ; Incidence ; Myoclonus ; Prospective Studies ; Unconsciousness

BACKGROUND: Etomidate is a rapid-acting sedative/hypnotic agent with little or no cardiovascular effect and a high therapeutic index. For this reason, etomidate has been used as an anesthetic induction and maintenance agent in patients with poor cardiovascular reserve. Bispectral index (BIS), a parameter derived from electroencephalography (EEG), has been proposed as a measure of anesthetic effect and is shown to correlate with increasing sedation and loss of consciousness. To establish its utility for this purpose, it is important to determine the correlation among BIS, measured drug concentration, and increasing levels of sedation. This study was designed to evaluate this relation for etomidate. METHODS: Eighteen adult patients scheduled for elective surgery, ASA physical status I or II, were included. Etomidate was administerd until loss of consciousness (loss of verbal contact) using syringe pump with a constant rate (150 ml/h) and patients were observed until regaining consciousness as decided by prompt verbal response on command of "open your eyes". A BIS was monitored, arterial blood samples were obtained for analysis of drug concentration, and the patients were evaluated for level of sedation by the responsiveness portion of the modified observer's assessment of alertness/sedation (OAA/S) scale. RESULTS: The BIS (r = 0.86) correlated significantly with the OAA/S more than the etomidate plasma concentration (r = 0.57). The BIS values, OAA/S, and blood concentrations were 50, 1.26, and 1337 ng/ml at induction and 75, 4.6, and 236 ng/ml at awakening, respectively. CONCLUSIONS: We concluded that the BIS accurately predicted level of sedation with etomidate during anesthesia induction, but the correlation between blood concentration and level of sedation was less strong.
Adult ; Anesthesia* ; Anesthetics ; Consciousness ; Electroencephalography ; Etomidate* ; Humans ; Plasma ; Syringes ; Unconsciousness

BACKGROUND: Etomidate frequently induces myoclonus when administered intravenously with bolus injection during anesthetic induction. This can be bothersome for the anesthesiologist. The dose of remifentanil appropriate for preventing myoclonus without side effects was investigated. METHODS: All patients with American Society of Anesthesiologists (ASA) physical status I-III were divided into three groups (n = 33 per group) according to the pretreatment effect site concentration of remifentanil (Ultiva, Glaxo-Wellcome, Munchen, Germany) of 0, 2 or 4 ng/ml (Group N: 0 ng/ml, Group R: 2 ng/ml, Group Q: 4 ng/ml) by a target controlled infusion (TCI) system. After a 0.3 mg/kg dose of etomidate was injected intravenously for over 1 minute for anesthetic induction, myoclonus was observed. Before the etomidate injection, the patients were pretreated with remifentanil and their side effects were monitored. RESULTS: The number of patients showing myoclonus was significantly different among the groups. The incidence of myoclonus was 81%, 12% and 0% (groups N, R, and Q, respectively, P < 0.01). Side effects including bradycardia and hypotension did not occur in either Group R or Q. Chest wall rigidity occured in 45% of patients in Group Q. CONCLUSIONS: Administration with a 2 ng/ml effect site concentration of remifentanil could reduce the incidence of myoclonus caused by etomidate bolus injection without chest wall rigidity.
Bradycardia ; Etomidate ; Humans ; Hypotension ; Incidence ; Myoclonus ; Piperidines ; Thoracic Wall

BACKGROUND: Redistribution hypothermia can be modified by the effects of induction anesthesia on the systemic vascular resistance. This study compared the effects of etomidate and propofol on redistribution hypothermia during general anesthesia. METHODS: Forty patients were randomly allocated into one of two groups, based on the induction agent used: Group E (n = 20) received 0.2 mg/kg of etomidate and group P (n = 20) received 2.5 mg/kg propofol. After intubation, anesthesia was maintained with sevoflurane and 50% nitrous oxide in oxygen in both groups. The core and peripheral temperatures were measured, and the peripheral temperature gradients (forearm minus fingertip) were used as an index of an arteriovenous shunt. RESULTS: The patients in both groups demonstrated intense vasoconstriction prior to the induction of anesthesia with similar skin-temperature gradients. After induction, group P showed more rapid and significant vasodilation than group E (P = 0.02). The difference in vasodilation between the two groups disappeared from 5 minutes after intubation. The pre-induction core temperatures were similar in both groups. After induction, the core temperatures in group P were consistently lower than those in group E (P < 0.01). The core temperatures during the first hour of anesthesia decreased by 1.5 +/- 0.4 degrees C in group P but only by 0.9 +/- 0.4 degrees C in group E. Conclusions: Propofol caused more rapid and aggravated redistribution hypothermia during surgery than etomidate due to the earlier arteriovenous shunt vasodilation.
Anesthesia ; Anesthesia, General* ; Etomidate* ; Humans ; Hypothermia* ; Intubation ; Nitrous Oxide ; Oxygen ; Propofol* ; Vascular Resistance ; Vasoconstriction ; Vasodilation

BACKGROUND: Etomidate is short-acting non-barbiturate intravenous anesthetic with minimal cardiovascular depression. As a small change in venous capacitance significantly alters venous return and thus cardiac output, it is important to know the effects of intravenous anesthetics on venous capacitance. The purpose of this study was to examine the effect of etomidate or pentobarbital (control agent) on venous capacitance. METHOD: All twenty rats (etomidate group: 10, pentobarbital group: 10), weighing 350-450 gram, were anesthetized with pentobarbital 50 mg/kg given intraperitoneally for surgical preparation. Mean arterial pressure (MAP), heart rate (HR), and mean circulatory filling pressure (MCFP) were measured in the awake state(recovered from pentobarbital anesthesia for surgical preparation) as well as during anesthesia with etomidate or pentobarbital. Venous capacitance was assessed before and during anesthesia with etomidate or pentobarbital by measuring MCFP. MCFP was measured during a brief period of circulatory arrest produced by inflating a balloon inserted in right atrium. RESULTS: As compared with MCFP in the corresponding awake state, MCFP was not significantly altered by etomidate but significantly decreased by pentobarbital. As compared with MAP in the corresponding awake state, MAP was not significantly altered by etomidate but significantly decreased by pentobarbital. CONCLUSION: The results suggest that unaltered venous capacitance by etomidate may contribute to a maintained MAP but increased venous capacitance by pentobarbital decrease in MAP of the normovolemic rat.
Anesthesia ; Anesthetics, Intravenous ; Animals ; Arterial Pressure ; Cardiac Output ; Depression ; Etomidate* ; Heart Atria ; Heart Rate ; Pentobarbital ; Rats*

BACKGROUND: Good control of intraocular pressure (IOP) during induction and maintenance of anesthesia is essential for the success of intraocular surgery. Etomidate produces a significant and somewhat greater reduction in IOP than thiopental. This study was designed to compare the effects of etomidate on IOP with those of thiopental in patients receiving succinylcholine, and in whom tracheal intubation was performed. METHODS: Forty ASA physical status I or II patients undergoing elective surgery were divided into thiopental group (n = 20) or etomidate group (n = 20). Intraocular pressure was measured before induction, 1, 2, and 3 minutes after administration of an intravenous induction agent, after administration of succinylcholne, immediately after intubation and 2 minutes after intubation. Systolic blood pressure and heart rate were recorded simultaneously. RESULTS: Both agents produced significant decreases in IOP after administration. At 3 minutes after administration of an agent and after administration of succinylcholine, the IOP of the etomidate group was significantly lower than that of the thiopental group (P< 0.05), but there were no significant differences between the groups in IOP at other stages. CONCLUSIONS: Etomidate is not a more effective intravenous induction agent to control the increase of intraocular pressure following tracheal intubation with succinylcholine than thiopental.
Anesthesia* ; Anesthetics ; Blood Pressure ; Etomidate* ; Heart Rate ; Humans ; Intraocular Pressure* ; Intubation ; Succinylcholine ; Thiopental*

BACKGROUND: It has been reported that etomidate has the relaxant effects on vascular, tracheal, and non-pregnant uterine smooth muscle in vitro. The purpose of this study was to investigate the relaxant effects of etomidate on the contraction of the pregnant rat uterine smooth muscle. METHODS: Uterine muscle tissues were obtained from pregnant rats (n = 15). The uterine segments were mounted in organ baths filled with Krebs solution. After oxytocin-induced contractile activity had been established, etomidate in incremental concentrations (10(-7) to 10(-3) M) was added cumulatively to the bath, each administered 20 min apart, and resultant changes in contractile activity were continuously recorded. EC5 (effective concentration of 5% reduction), EC25, EC50, EC75, and EC95 on active tension were calculated using a probit model. RESULTS: Etomidate (10(-7) to 10(-3) M) induced dose-dependent decreases in amplitude and frequency of uterine contraction. The EC50 of etomidate on active tension were 5.91 x 10(-5) M. CONCLUSIONS: These results demonstrate that etomidate had inhibitory effects on pregnant rat uterine muscle at supraclinical concentration (5.91 x 10(-5) M).
Animals ; Baths ; Contracts ; Etomidate ; Female ; Isotonic Solutions ; Mice ; Muscle, Smooth ; Myometrium ; Oxytocin ; Rats ; Uterine Contraction