Metabolic Profile of Etomidate and Its Three Analogs in Zebrafish, Human Liver Microsomes, Human Urine and Hair Samples Using UHPLC-Q Exactive Orbitrap-HRMS

Etomidate is a short-acting non-barbiturate imidazole used as an intravenous anesthetic agent in humans, while metomidate and propoxate are common anesthetic drug for fishes. Today, etomidate, and its analogs, including isopropoxate, are increasingly abused, leading to many public malignant events. The goal of this work was to use liquid chromatography-high resolution mass spectrometry (LC-HRMS) to study the in vivo and in vitro metabolism of etomidate and its analogs in zebrafish, human liver microsomes (HLMs), human urine and hair samples. Eight metabolites of metomidate, 11 metabolites of etomidate, six metabolites of propoxate, and 10 metabolites of isopropoxate were detected in our study. The main metabolic pathways included hydroxylation, dealkylation, dehydrogenation, and glucuronidation. Etomidate acid and metomidate were detected in samples after metabolism of all four substances. Our results support the use of the monohydroxylated metabolites as metabolic biomarkers for etomidate and its analogs. Among the tested human samples, 38 samples showed one type of our targeted substances, and 20 samples showed two or more drugs. Thus, polydrug use in etomidate and its analogs was a phenomenon worth noting. This study is the first to identify target metabolic compounds for monitoring the abuse of etomidate and its analogs in human, and to provide insights into the in vivo and in vitro biotransformation of them.

Impact of anesthetic induction with etomidate, thiopentone, and propofol on regional cerebral oxygenation: An observational study in patients with traumatic brain injury

Background and Aims

Anesthetic induction plays a pivotal role in determining the operative course and the outcome in patients with acute traumatic brain injury (TBI). The present study compared the effect of anesthetic induction with etomidate, thiopentone, and propofol primarily on systemic hemodynamics and regional cerebral oxygenation (rScO2) and secondarily on the serum cortisol levels in TBI patients.

Material and Methods

In this prospective observational study, eligible patients were recruited and divided into three groups as per the induction agent received. Data collected were hemodynamic parameters and rScO2 levels at baseline, following 3 min of preoxygenation, and over 10 min of induction. Serum cortisol levels were measured before and after 24 h of induction. The statistical analysis was done using R software.

Results

A total of 115 patients were included: 32, 33, and 50 in thiopentone, propofol, and etomidate groups, respectively. A significant increase (P < 0.001) in bilateral rScO2 was noted in all three groups following anesthetic induction. Intergroup comparison of the propofol and the etomidate groups revealed significantly lesser increase in contralateral rScO2 (P = 0.019) and a greater fall in mean arterial pressure (P = 0.003) on using propofol as an induction agent. Trend changes in bilateral rScO2 and hemodynamic parameters were comparable between thiopentone and etomidate groups. An insignificant fall in serum cortisol was observed in etomidate (P = 0.332) and thiopentone (P = 0.364) groups, but a significant increase was observed in the propofol group (P = 0.004). The Glasgow coma scale (GCS) score at discharge improved significantly in all the groups (P < 0.001).

Conclusions

In TBI patients, anesthetic induction with etomidate resulted in least hemodynamic changes compared to induction with thiopentone and propofol. The rScO2 increased in all three groups after induction, with the maximal increase observed with etomidate compared to propofol and thiopentone. Insignificant fall in serum cortisol was observed with etomidate and thiopentone, but not with propofol. Outcome at discharge, assessed with GCS, was comparable in all the groups.

Endocrine Dysfunction After Traumatic Brain Injury: An Ignored Clinical Syndrome?

Traumatic brain injury (TBI) incurs substantial health and economic burden, as it is the leading reason for death and disability globally. Endocrine abnormalities are no longer considered a rare complication of TBI. The reported prevalence is variable across studies, depending on the time frame of injury, time and type of testing, and variability in hormonal values considered normal across different studies. The present review reports evidence on the endocrine dysfunction that can occur after TBI. Several aspects, including the pathophysiological mechanisms, clinical consequences/challenges (in the acute and chronic phases), screening and diagnostic workup, principles of therapeutic management, and insights on future directions/research agenda, are presented. The management of hypopituitarism following TBI involves hormonal replacement therapy. It is essential for health care providers to be aware of this complication because at times, symptoms may be subtle and may be mistaken to be caused by brain injury itself. There is a need for stronger evidence for establishing recommendations for optimum management so that they can be incorporated as standard of care in TBI management.

Etomidate Alleviates Ischemia-Anoxia Reperfusion Injury in Intestinal Epithelial Cells by Inhibiting the Activation of traf6-Regulated NF-KB Signaling

Objective: The present study aimed to investigate the role of etomidate in intestinal cell ischemia and hypoxia-reperfusion injury and potential mechanisms. Method: In this study, we establish the intestinal epithelial cells ischemia-reperfusion model in vitro. CCK8 was used to detect cell viability and flow cytometry assay was used to detect apoptosis levels of treated OGD/R model cells. ELISA measured the expression level of oxidative stress factors and inflammatory factors. Furthermore, western blot assay was used to detect the expression the apoptosis-related factors and TNFR-associated factors in treated OGD/R model cells. Result: Etomidate does not affect the activity of intestinal epithelial cells, and can protect intestinal epithelial cells to reduce ischemiareperfusion injury, and the expression of inflammatory factors and oxidative stress in cells with mild intestinal epithelial ischemia-reperfusion injury. Etomidate alleviates apoptosis of intestinal epithelial ischemia-reperfusion injury cells. Etomidate inhibits the activation of traf6-mediated NF-κB signal during ischemia-anoxia reperfusion of intestinal epithelial cells. Conclusion: Taken together, our study demonstrated that etomidate attenuates inflammatory response and apoptosis in intestinal epithelial cells during ischemic hypoxia-reperfusion injury and inhibits activation of NF-κB signaling regulated by TRAF6.

Sedation for Rapid Sequence Induction and Intubation of Neurologically Injured Patients

There are subtle physiologic and pharmacologic principles that should be understood for patients with neurologic injuries. These principles are especially true for managing patients with traumatic brain injuries. Prevention of hypotension and hypoxemia are major goals in the management of these patients. This article discusses the physiology, pitfalls, and pharmacology necessary to skillfully care for this subset of patients with trauma. The principles endorsed in this article are applicable both for patients with traumatic brain injury and those with spinal cord injuries.

Device and Medication Preferences of Canadian Physicians for Emergent Endotracheal Intubation in Critically Ill Patients

OBJECTIVES

Various medications and devices are available for facilitation of emergent endotracheal intubations (EETIs). The objective of this study was to survey which medications and devices are being utilized for intubation by Canadian physicians.

METHODS

A clinical scenario-based survey was developed to determine which medications physicians would administer to facilitate EETI, their first choice of intubation device, and backup strategy should their first choice fail. The survey was distributed to Canadian emergency medicine (EM) and intensive care unit (ICU) physicians using web-based and postal methods. Physicians were asked questions based on three scenarios (trauma; pneumonia; heart failure) and responded using a 5-point scale ranging from "always" to "never" to capture usual practice.

RESULTS

The survey response rate was 50.2% (882/1,758). Most physicians indicated a Macintosh blade with direct laryngoscopy would "always/often" be their first choice of intubation device in the three scenarios (mean 85% [79%-89%]) followed by video laryngoscopy (mean 37% [30%-49%]). The most common backup device chosen was an extraglottic device (mean 59% [56%-60%]). The medications most physicians would "always/often" administer were fentanyl (mean 45% [42%-51%]) and etomidate (mean 38% [25%-50%]). EM physicians were more likely than ICU physicians to paralyze patients for EETI (adjusted odds ratio 3.40; 95% CI 2.90-4.00).

CONCLUSIONS

Most EM and ICU physicians utilize direct laryngoscopy with a Macintosh blade as a primary device for EETI and an extraglottic device as a backup strategy. This survey highlights variation in Canadian practice patterns for some aspects of intubation in critically ill patients.

Pros and cons of etomidate--more discussion than evidence?

PURPOSE OF REVIEW

To evaluate the most recent publications in the long-lived debate over the use of etomidate in critically ill septic and trauma patients.

RECENT FINDINGS

Virtually without controversy is the hemodynamic stability after its use for induction of anesthesia on the one hand, and its negative effect on steroid synthesis on the other. The rating of the relative importance of both phenomena for the outcome of patients is however a highly controversial issue. We will discuss the most recent publications for two patient groups: trauma and critically ill septic patients. New meta-analyses and smaller studies have been published and might help us to weigh pros and cons in our patients. Sufficiently powered randomized controlled trials remain absent. The question whether supplemented corticosteroids after etomidate improve outcome is answered negatively by two recent studies.

SUMMARY

A single dose of etomidate supplies good intubation conditions with hemodynamic stability, but increases the risk for adrenal insufficiency. The relative importance of these characteristics for the patients' outcome remains controversial, as there is a lack of direct evidence. According to the principle 'nihil nocere', reasoning argues against its use, especially in septic patients or in those at major risk to develop septic complications (e.g. trauma patients).