DEXMEDETOMIDINE, A NOVEL ANESTHETIC FOR BOTH GENERAL AND REGIONAL ANESTHESIA

Abstract

Alpha 2 adrenoceptor agonists are being increasingly used in anesthesia and critical care as they not only decrease sympathetic tone and attenuate the stress responses to anesthesia and surgery; but also cause sedation and analgesia. They are also used as adjuvant during regional anesthesia. Clonidine, which was initially introduced as antihypertensive, is the most commonly used α 2 agonist by anesthesiologists. Dexmedetomidine is the most recent agent in this group approved by FDA in 1999 for use in humans for analgesia and sedation (Ralph Gertler et al., 2001). The benefits of a sedative that minimally affects the control of breathing are clear. The lack of respiratory depression with Dexmedetomidine use provides practitioners with a sedative and anxiolytic tool that can be used before, during, and after completion of the extubation process. Dexmedetomidine may also allow control of agitation immediately after extubation, or with the use of mask ventilation where a calm, cooperative patient is essential to successful management (Venn et al., 2000). Dexmedetomidine lower the tachycardic response to endotracheal intubation and assures a greater hemodynamic stability during the intraoperative period. It has the ability to potentiate the anesthetic requirements for opioids as well as volatile and regional agents. Several studies have demonstrated the beneficial effects of Dexmedetomidine premedication in patients with coronary artery disease because it allows a stable perioperative hemodynamic (Unlugenc et al., 2005), as well as a special antiarrhythmic effect (Choudhury. 2015). Dexmedetomidine hastens the onset of sensory block in spinal anaesthesia and prolongs the time to first analgesic request in the setting of spinal anaesthesia (Brull et al., 2013), While clonidine produces preferential extension of sensory block, Dexmedetomidine prolongs both sensory and motor block, (Brull et al., 2013). The addition of dexmedetomidine to lidocaine for Intravenous Regional Anesthesia (IVRA) improved quality of anesthesia and intraoperative postoperative analgesia without causing side effects (Memis et al, 2004).