Dexmedetomidine Versus Lidocaine for Optic Nerve Sheath Diameter During Craniotomy Intubation

Endotracheal intubation during general anesthesia can cause temporary increases in heart rate, blood pressure, and intracranial pressure. These changes may be particularly important in patients undergoing craniotomy. Optic nerve sheath diameter, measured noninvasively using ultrasound, can be used as an indirect marker of changes in intracranial pressure. This randomized controlled trial will compare intravenous dexmedetomidine, intravenous lidocaine, and normal saline in patients undergoing elective supratentorial craniotomy under general anesthesia. The study will evaluate whether dexmedetomidine or lidocaine can reduce changes in optic nerve sheath diameter associated with endotracheal intubation and improve hemodynamic stability compared with placebo. The investigators hypothesize that dexmedetomidine and lidocaine will attenuate the increase in optic nerve sheath diameter and the hemodynamic response associated with endotracheal intubation.