A comparative study of two infusion doses of etomidate for induction vs standard induction dose of etomidate

Effects and mechanisms of perioperative medications on the hypothalamic pituitary adrenal response to surgical injury: A narrative review

The adrenal gland is a vital endocrine organ, and adrenal steroid synthesis and secretion are closely regulated by the hypothalamic-pituitary-adrenal (HPA) axis in response to various stimuli. Surgery or trauma can activate the HPA axis and induce the secretion of cortisol. Different cortisol responses vary with the grade of surgery. Perioperative medications have the potential to decrease the cortisol level in the body, and both excessive and insufficient cortisol levels after surgery are disadvantageous. The effect of perioperative medications on the HPA response to surgery can be divided into three levels: "adrenal insufficiency (AI)", "stress response inhibition", and "uncertainty". The clinical presentation of AI includes fatigue, nausea, vomiting, abdominal pain, muscle cramps, hypotension, hypovolemic shock and prerenal failure, which may result in fatal consequences. Stress response inhibition can reduce postoperative complications, such as pain and cognitive dysfunction. This is protective to patients during perioperative and postoperative periods. The aim of the present review is to shed light on current evidence regarding the exact effects and mechanisms of perioperative medications on the HPA response to surgical injury and provide the applicable guidance on clinical anesthesia.

Effect of Etomidate vs Propofol for Total Intravenous Anesthesia on Major Postoperative Complications in Older Patients: A Randomized Clinical Trial

Question

Does etomidate compared with propofol provide a noninferior effect on in-hospital morbidity when used for induction and maintenance of general anesthesia in older patients undergoing abdominal surgery?

Findings

In this randomized clinical trial involving 1944 older patients who underwent elective abdominal surgery, the rate of major in-hospital complications was noninferior between patients who received etomidate and those who received propofol for general anesthesia (9.3% vs 8.7%).

Meaning

Findings of this trial indicate that etomidate anesthesia does not increase postoperative morbidity in older patients compared with propofol.

Importance

Older patients may benefit from the hemodynamic stability of etomidate for general anesthesia. However, it remains uncertain whether the potential for adrenocortical suppression with etomidate may increase morbidity.

Objective

To test the primary hypothesis that etomidate vs propofol for anesthesia does not increase in-hospital morbidity after abdominal surgery in older patients.

Design, Setting, and Participants

This multicenter, parallel-group, noninferiority randomized clinical trial (Etomidate vs Propofol for In-hospital Complications [EPIC]) was conducted between August 15, 2017, and November 20, 2020, at 22 tertiary hospitals in China. Participants were aged 65 to 80 years and were scheduled for elective abdominal surgery. Patients and outcome assessors were blinded to group allocation. Data analysis followed a modified intention-to-treat principle.

Interventions

Patients were randomized 1:1 to receive either etomidate or propofol for general anesthesia by target-controlled infusion.

Main Outcomes and Measures

Primary outcome was a composite of major in-hospital postoperative complications (with a noninferiority margin of 3%). Secondary outcomes included intraoperative hemodynamic measurements; postoperative adrenocortical hormone levels; self-reported postoperative pain, nausea, and vomiting; and mortality at postoperative months 6 and 12.

Results

A total of 1944 participants were randomized, of whom 1917 (98.6%) completed the trial. Patients were randomized to the etomidate group (n = 967; mean [SD] age, 70.3 [4.0] years; 578 men [59.8%]) or propofol group (n = 950; mean [SD] age, 70.6 [4.2] years; 533 men [56.1%]). The primary end point occurred in 90 of 967 patients (9.3%) in the etomidate group and 83 of 950 patients (8.7%) in the propofol group, which met the noninferiority criterion (risk difference [RD], 0.6%; 95% CI, –1.6% to 2.7%; P = .66). In the etomidate group, mean (SD) cortisol levels were lower at the end of surgery (4.8 [2.7] μg/dL vs 6.1 [3.4] μg/dL; P < .001), and mean (SD) aldosterone levels were lower at the end of surgery (0.13 [0.05] ng/dL vs 0.15 [0.07] ng/dL; P = .02) and on postoperative day 1 (0.14 [0.04] ng/dL vs 0.16 [0.06] ng/dL; P = .001) compared with the propofol group. No difference in mortality was observed between the etomidate and propofol groups at postoperative month 6 (2.2% vs 3.0%; RD, –0.8%; 95% CI, –2.2% to 0.7%) and 12 (3.3% vs 3.9%; RD, –0.6%; 95% CI, –2.3% to 1.0%). More patients had pneumonia in the etomidate group than in the propofol group (2.0% vs 0.3%; RD, 1.7%; 95% CI, 0.7% to 2.8%; P = .001). Results were consistent in the per-protocol population.

Conclusions and Relevance

Results of this trial showed that, compared with propofol, etomidate anesthesia did not increase overall major in-hospital morbidity after abdominal surgery in older patients, although it induced transient adrenocortical suppression.

Trial Registration

ClinicalTrials.gov Identifier: NCT02910206

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.

Ketamine Versus Etomidate and Peri-intubation Hypotension: A National Emergency Airway Registry Study

BACKGROUND

The hemodynamic impact of induction agents is a critically important consideration in emergency intubations. We assessed the relationship between peri-intubation hypotension and the use of ketamine versus etomidate as an induction agent for emergency department (ED) intubation.

METHODS

We analyzed ED intubation data for patients aged >14 years from the National Emergency Airway Registry performed in 25 EDs during 2016 through 2018. We excluded patients with preintubation hypotension (systolic blood pressure <100 mm Hg) or cardiac arrest prior to intubation. The primary outcome was peri-intubation hypotension. Secondary outcomes included interventions for hypotension (e.g., intravenous fluids or vasopressors). We report adjusted odds ratios (aOR) from multivariable logistic regression models controlling for patient demographics, difficult airway characteristics, and intubation modality.

RESULTS

There were 738 encounters with ketamine and 6,068 with etomidate. Patients receiving ketamine were more likely to have difficult airway characteristics (effect size difference = 8.8%, 95% confidence interval [CI] = 5.3% to 12.4%) and to undergo intubation with video laryngoscopy (8.1%, 95% CI = 4.4% to 12.0%). Peri-intubation hypotension incidence was 18.3% among patients receiving ketamine and 12.4% among patients receiving etomidate (effect size difference = 5.9%, 95% CI = 2.9% to 8.8%). Patients receiving ketamine were more likely to receive treatment for peri-intubation hypotension (effect size difference = 6.5%, 95% CI = 3.9% to 9.3%). In logistic regression analyses, patients receiving ketamine remained at higher risk for peri-intubation hypotension (aOR = 1.4, 95% CI = 1.2 to 1.7) and treatment for hypotension (aOR = 1.8, 95% CI = 1.4 to 2.0). There was no difference in the aOR of hypotension between patients receiving ketamine at doses ≤1.0 mg/kg versus >1.0 mg/kg or patients receiving etomidate at doses ≤0.3 mg/kg versus >0.3 mg/kg.

CONCLUSIONS

Pending additional data, our results suggest that clinicians should not necessarily prioritize ketamine over etomidate based on concern for hemodynamic compromise among ED patients undergoing intubation.