Intranasal dexmedetomidine versus intranasal midazolam as pre anesthetic medication in pediatric age group undergoing adenotonsillectomy

Abstract

he preoperative period is a stressful event for the majority of individuals undergoing surgery. This is especially true in the pediatric patient. This leads to tachycardia, agitation or excessive crying, which make the management of such patients difficult during induction of anaesthesia. Also, extreme anxiety and stress before surgery has been reported to result in negative postoperative sequelae such as emergence delirium, maladaptive behavior, and increased postoperative pain. Pharmacological and behavioral interventions are used to treat preoperative anxiety in children and their parents. The major objectives of preanesthetic medication are to decrease the stress response with preservation of hemodynamic parameters, facilitate anesthesia induction and produce amnesia. Many anxiolytic medications have been tried with varying results. The ideal premedication should be readily acceptable, should have a rapid reliable onset with minimal side effects. Of the benzodiazepines, midazolam has become the most frequently used premedication due to its fast onset and short duration of action. It potentiates the binding of the inhibitory neurotransmitter GABA which promotes GABA A postsynaptic receptor opening to chloride ions, thus hyperpolarizing the cell membrane and preventing the generation of an action potential. Sedation, hypnosis, muscle relaxation, anxiolysis and anticonvulsant effects through this mechanism. Intranasal midazolam has got some advantage. Owing to high mucosal vascularity, intranasal route offers rapid onset and high bioavailability as it avoids the hepatic first pass metabolism. The major risk associated with high doses of midazolam is hypoventilation and associated hypoxemia. The sedative effect of midazolam can be reversed by IV administration of flumazenil.