Intravenous Magnesium Sulphate Versus Dexmedetomidine for Prevention of Emergence Agitation in Adult Otorhinolaryngologic Surgery

This multicenter, double-blinded, randomized controlled trial was designed to evaluate two intraoperative pharmacologic strategies used during general anesthesia for adult otorhinolaryngologic surgery. The study is based on differing pharmacodynamic mechanisms: dexmedetomidine provides central sympatholysis via selective α2-adrenergic receptor activation, while magnesium sulphate modulates neuronal excitability primarily through NMDA receptor antagonism and calcium channel blockade. Both agents are administered as continuous infusions during surgery without a loading dose to allow steady-state effects and minimize abrupt hemodynamic changes. Randomization is performed using a computer-generated sequence with allocation concealment. Study medications are prepared by independent pharmacy personnel in identical syringes to maintain blinding of anesthesia providers, patients, and investigators. Perioperative anesthetic management is standardized across sites to reduce variability in clinical practice. Physiologic parameters are recorded at predefined perioperative intervals using structured case report forms. Data are analyzed using appropriate statistical methods based on distribution characteristics, including longitudinal modeling to account for repeated intra-subject measurements. A two-sided significance threshold is prespecified for all analyses.