This study aimed to compare two cut-off values of plethysmographic variability index (PVI) -guided fluid therapy in patients undergoing supra-tentorial mass excision regarding immediate postoperative serum lactate.

Fluid therapy in patients undergoing craniotomy is very critical; hypovolemia might decrease cerebral perfusion, while fluid overinfusion might cause brain swelling that impairs surgical removal of lesions.

The plethysmographic variability index (PVI) is one of the dynamic indices of fluid responsiveness, a simple, automatic, non-invasive, and continuous method based on calculating changes in the perfusion index (PI).

Inclusion Criteria:

• Age above 18 years old.
• Both sexes.
• Patients scheduled for supra-tentorial brain tumor excision.

Exclusion Criteria:

• Arrhythmias.
• Pulmonary hypertension.
• Impaired cardiac contractility.
• Impaired liver or kidney function.
• Low lung compliance.
• Body mass index above 40.
• Intra-operative hemodynamic instability on vasopressors or inotropes.
• Peripheral arterial occlusive diseases.
• Hand injuries or burns that preclude the application of the Masimo device probe.

The data will be available upon a reasonable request from the corresponding author after the end of study for one year.

After the end of study for one year.

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