This prospective observational study aims to evaluate the effect of internal jugular vein catheterization on intracranial pressure using optic nerve sheath diameter (ONSD) measurements and carotid artery Doppler ultrasonography in adult patients undergoing surgery under general anesthesia.
ONSD will be measured noninvasively using transorbital ultrasonography, and carotid Doppler parameters will be assessed at two time points: after endotracheal intubation and approximately 5 minutes after catheterization. The primary objective is to assess short-term changes in ONSD following catheterization.
Secondary objectives include evaluating changes in carotid Doppler measurements and their relationship with ONSD, as well as associations with physiological parameters such as blood pressure, heart rate, oxygen saturation, and end-tidal carbon dioxide.
Age ≥18 years
Patients undergoing surgery under general anesthesia
Patients requiring internal jugular vein catheterization as part of routine clinical care
Ability to obtain optic nerve sheath diameter measurements using transorbital ultrasonography
Known intracranial pathology affecting intracranial pressure
Ocular conditions preventing accurate ultrasonographic measurement (e.g., orbital trauma, ocular surgery, infection)
Hemodynamic instability
Contraindication to internal jugular vein catheterization