Lidocaine, Dexmedetomidine, Esmolol and Magnesium Effect on Optic Nerve Sheath Diameter After Laryngoscopy

This clinical trial aims to compare the effects of lidocaine, dexmedetomidine, esmolol, and magnesium on optic nerve sheath diameter and hemodynamic response to laryngoscopy. The participants will be patients determined to need intubation and general anesthesia for any elective surgery. Each participant will receive either lidocaine, dexmedetomidine, esmolol, magnesium, or none before anesthesia induction, according to randomization. The investigator will measure the optic nerve sheath diameter by ultrasonography before and after intubation. Researchers will compare the difference between optic nerve sheath diameter, systolic blood pressure, and heart rate before and after laryngoscopy and search for the most stable group. The trial aims to determine a general anesthesia induction protocol for patients sensitive to intracranial pressure changes reflected as optic nerve sheath diameter for easy monitoring.