The Lloyd Davies position is a position used in laparoscopic hysterectomies where the head is lowered 45 degrees and the legs are bent from the knee area.It is a version of the Trendelenburg position. Both this position and for laparoscopic surgery carbon dioxide (CO2) gas given into the abdomen, causes problems for the patient. Increased abdominal and thoracic pressure impairs venous return and increases intracranial pressure. Optic nerve sheath diameter can be measured by placing an ultrasound probe over the eye. It is possible to follow up the increase in intracranial pressure with this diameter measurement. In this study, it was planned to measure the optic nerve sheath diameter by ultrasound in patients who will undergo laparoscopic hysterectomy. It is aimed to observe the changes in the increase in intracranial pressure as the time lengthens with the measurements to be made at certain intervals during the operation. Secondary aim is to determine whether there is a cut-off value where the intracranial pressure starts to increase.

The Trendelenburg position is the patient's head down with the table tilted, with the head closer to the floor than the feet. Lloyd Davies position is a modified version of the Trendelenburg position, used especially in laparoscopic hysterectomies, where the head is lowered 30-45° and the legs are bent at knee level. During this surgery, pneumoperitoneum is also applied by administering carbon dioxide (CO2) into the abdomen. During this surgery, pneumoperitoneum is also applied by administering CO2 into the abdomen. The applied position and intra-abdominal CO2 cause some physiological changes. These changes include respiratory and cardiac changes as well as increased intracranial pressure. Optic nerve sheath diameter can be measured by placing an ultrasound probe over the eye. Increase in intracranial pressure can be followed by sequential measurements. In this study, it was planned to measure the optic nerve sheath diameter by ultrasound in patients who will undergo laparoscopic hysterectomy. It is aimed to observe the changes in the increase in intracranial pressure as the time lengthens with the measurements to be made at certain intervals during the operation. Before the patients were given anesthesia induction, optic nerve sheath diameter measurement (ONSD) was performed by imaging in the sagittal and transverse planes in both eyes in neutral position. The second measurement was taken 2 minutes after endotracheal intubation in the neutral position. After the trocars were placed and pneumoperitoneum was applied, the patient was placed in the Lloyd Davies position. After the position was given, bilateral ONSD measurements were taken at the 30th minute, 60th minute, 75th minute, and 90th minute. At the end of the surgery, pneumoperitoneum and position were neutralized. The last measurement was taken 5 minutes after the patient was placed in the neutral position. Near infrared spectrometry (NIRS) monitoring was performed throughout the surgery.

Inclusion Criteria:

• Patients who will undergo laparoscopic hysterectomy

Exclusion Criteria:

• chronic lung disease, pulmonary hypertension
• glaucoma
• history of eye surgery
• diabetic retinopathy
• intracranial mass,
• hydrocephalus
• history of intracranial surgery
• American society of anesthesiology (ASA) physical classification IV
• optic neuritis
• who do not want to participate in the study.

Patients who will undergo laparoscopic hysterectomy

There is not a plan to make individual participant data (IPD) available.