We hypothesize that intravenous lidocaine infusion may have beneficial effect to patients undergoing laparoscopic surgeries in Trendelenburg position by preventing ICP elevation.

Lidocaine use, both intravenous (IV) and laryngotracheal (LT), has been reported to blunt the ICP elevations during intubation. Also, Lidocaine injected IV has been shown in models to induce cerebral vasoconstriction leading to a decrease in cerebral blood volume and thus ICP. Furthermore, IV lidocaine leads to sodium channel inhibition and thus a reduction in cerebral activity and metabolic demands, as well as excitotoxicity, leading to a potential ICP reduction effect.

Inclusion Criteria:

• Aged between 35 to 65 years
• American society of anesthesiology (ASA) physical status I - II
• Body mass index (BMI) between 18.5 to 28.0 kg/m2
• Scheduled for total laparoscopic hysterectomy taking approximately 2 h with a 30° Trendelenburg position for management of uterine fibroids or refractory dysfunctional uterine bleeding.

Exclusion Criteria:

1. Patients with eye diseases, central nervous system diseases, cardiovascular diseases, cerebrovascular diseases or diabetes.

2. If these events occurred intraoperative:

   • Ultrasound scans or measurements failed to clearly show the structure of Optic Nerve Sheath Diameter (ONSD).
   • Surgical time less than 1 h.
   • Interruption of carbon dioxide (CO2) pneumoperitoneum and Trendelenburg position.
   • Peak airway pressure exceeding 35 cm H2O

3. Patients with a history of allergy to lidocaine.

Female patients scheduled for laparoscopic hysterectomy surgery.

The data will be available upon reasonable request from the corresponding author

After completion of the study

The data will be available upon reasonable request from the corresponding author