Etomidate is not used for long term infusion because?

Ans. is 'a' i.e., Results in adrenal suppression * Etomidate suppresses corticosteroid synthesis in the adrenal cortex by reversibly inhibiting 11 b-hydroxylase, which coverts 11-deoxycortisol to cortisol and by a relative minor effect on 17a - hydroxylase.* There is decreased synthesis of adrenal corticoids with increase in precursors 11-deoxycortisol and 17-hydroxyprogesterone.* ACTH secretion increases due to loss of feedback inhibition.* Using a continuous etomidate infusion for sedation of critically ill trauma patients in intensive care units has been associated with increased mortality due to adrenal suppression.* The mortality of patients exposed to a continuous infusion of etomidate for more than 5 days increased from 25% to 44%, mainly due to infectious causes such as pneumonia.* Vit 'C' supplementation restores cortisol levels to normal after use of etomidate.About other options* It produces little cardiovascular and respiratory depression - Agent of choice for cardiovascular surgeries (bypass, aneurysms, valve surgery). Etomidate is most cardiostable inducing agent. Coronary perfusion pressure is maintained when it is used with fentanyl.* Similar to thiopentone & propofol, etomidate is cerebroprotective - Decreases cerebral blood flow, metabolism, oxygen consumption and ICT.* Superficial thrombophlebitis and pain may occur on IV injection but intraarterial injection is not associated with local or vascular complications.