Etomidate and general anesthesia: the butterfly effect?

Anaesthetic management in endovascular total aortic arch repair via needle-based in situ fenestration: a case series of 14 patients

Objective

Endovascular total aortic arch repair (ETAAR) via needle-based in situ fenestration (ISF) is a major challenge for anaesthesiologists because of haemodynamic instability and the risk of cerebral hypoxia. We herein summarise our experience with anaesthetic management of patients who underwent this procedure.

Methods

Fourteen patients who underwent ETAAR via ISF for arch pathologies involving the major supra-arch branches were included. Regional cerebral oxygen saturation was measured to monitor cerebral perfusion. Partial extracorporeal circulation (EC) support from the right common femoral vein to the right axillary artery was introduced to provide cerebral perfusion.

Results

During ISF, vessel rupture occurred in three patients and ventricular fibrillation occurred in one patient. The regional cerebral oxygen saturation significantly decreased during the potential risk period for cerebral ischaemia. Establishment of EC effectively prevented cerebral ischaemia.

Conclusions

During ETAAR, the risks of haemodynamic instability caused by the procedure and vessel rupture during ISF need to be overcome. Partial EC ensured good cerebral protection in our study, and regional cerebral oxygen saturation monitoring may help to reduce the rate of desaturation.

Comparing Hemodynamic Responses to Diazepam, Propofol and Etomidate During Anesthesia Induction in Patients with Left Ventricular Dysfunction Undergoing Coronary Artery Bypass Graft Surgery: a Double-blind, Randomized Clinical Trial

Background:

Anesthesia induction is often accompanied by a period of hemodynamic instability, which could be deleterious in patients with coronary artery disease (CAD) and left ventricular dysfunction undergoing coronary artery bypass graft (CABG) surgery. The aim of this study was to compare the hemodynamic responses to propofol, etomidate, and diazepam following anesthesia induction, laryngoscopy and intubation in CABG surgery patients with low ejection fraction (EF).

Methods:

A double-blind randomized, clinical study was performed on 150 patients with CAD and left ventricular dysfunction (EF≤35%) scheduled for elective CABG surgery with Cardiopulmonary bypass (CPB). Patients were randomly allocated to three groups A, B, and C. These patients received propofol, etomidate or diazepam at induction of anesthesia, respectively. Hemodynamic variables (systolic and diastolic blood pressure [SBP, DBP], mean arterial pressure [MAP] and heart rate [HR]) were measured and recorded at baseline, immediately before laryngoscopy and tracheal intubation and one and three minutes after intubation.

Result:

One minute after induction and before laryngoscopy, there was a statistically significant decrease from the baseline in SBP, DBP and MAP in all three groups, but these variables in each hemodynamic parameters in diazepam group were less than other two groups (p<0.001). Moreover, the mean HR decreased in patients receiving propofol and etomidate one minute after induction and before laryngoscopy, but did not decreased in the diazepam group (p=0.005).

Conclusion:

The present study showed that in patients undergoing CABG surgery with low EF, diazepam is more favorable in terms of hemodynamic stability compared to propofol and etomidate and this drug can be used safely for induction of anesthesia in patients with impaired ventricular function.

The etomidate analog ET-26 HCl retains superior myocardial performance: Comparisons with etomidate in vivo and in vitro

OBJECTIVE

(R)-2-methoxyethyl1-(1-phenylethyl)-1H-imidazole-5-carboxylate hydrochloride (ET-26 HCl) is a novel etomidate analogue. The purpose of this study was to characterize whether ET-26 HCl could retain the superior myocardial performance of etomidate in vivo and in vitro.

METHODS

In vivo, the influence of ET-26 HCl and etomidate on the cardiac function of dogs was confirmed using echocardiography and electrocardiogram. In vitro, a Langendorff preparation was used to examine direct myocardial performance in isolated rat hearts, and a whole-cell patch-clamp technique was used to study effects on the human ether-a-go-go-related gene (hERG) channel.

RESULTS

In vivo, after a single bolus administration of ET-26 HCl or etomidate, no significant difference in echocardiography and electrocardiogram parameters was observed. No arrhythmia occurred and no QT interval prolongation happened during the study period. In the in vitro Langendorff preparation, none of the cardiac parameters were abnormal, and the hERG recordings showed that ET-26 HCl and etomidate inhibited the tail current of the hERG in a concentration-dependent manner with an IC50 of 742.51 μM and 263.60 μM, respectively.

CONCLUSIONS

In conclusion, through an in vivo experiment and a whole organ preparation, the current study found that ET-26 HCl can maintain a myocardial performance that is similar to that of etomidate. In addition, the electrophysiology study indicated that ET-26 HCl and etomidate inhibited the hERG at a supra-therapeutic concentration.