Evaluation of the Effect of Trendelenburg Position Duration on Intracranial Pressure

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.