Comparison Between Dexmedetomidine And Remifentanil For Attenuation Of Hemodynamic Response To Laryngoscopy And Tracheal Intubation

Laryngoscopy and endotracheal intubation are essential components of general anesthesia , facilitating airway control and mechanical ventilation .However these procedure are potent stimuli that can evoke marked sympathetic and hemodynamic response , characterized by tachycardia, hypertension and arrhythmias . These reflex cardiovascular changes result primarily from the stimulation of the supraglottic and subglottic structure , leading to a surge in catecholamine release mediated by sympathetic activation. Although transient in healthy individuals, these responses may have deleterious effects in cardiovascular or cerebrovascular disease, including myocardial ischemia ,heart failure exacerbation, or intracranial hypertension.

Dexmedetomidine selectively in alpha -2 adrenergic located in the locus coeruleus of the brainstem and peripheral sympathetic nerve terminals .Activation of these receptors results in the inhibition of norepinephrine release, decrease sympathetic activity ,and enhancement of parasympathetic tone.

Remifentanil is rapidly acting with short context -sensitive half -life ,and metabolism by non specific plasma and tissue esterases . It exerts it effect by activating opioid receptors in the central nervous system ,reducing sympathetic outflow and inhibiting catecholamine release.