Effect of Optıc Nerve Dıameter ın Tymphanoplasty Surgery Performed ın Lateral Head Posıtıon

Studies exist to determine the effect of laparoscopic surgical procedures on increased intra-abdominal pressure; these studies include optic nerve sheath diameter (ONSD) measurement in various positions such as trendelenburg and prone, and the effect of the laryngoscope used in intubation on increased intracranial pressure. In these situations, changes in cerebral blood flow and intracranial pressure may occur due to impaired neck venous return. There are no studies in the literature regarding increased osd and consequently increased intracranial pressure in lateral head position.ultrasound for ONSD measurement is a non-invasive, rapid, and easily applicable method for diagnosing changes in intracranial pressure. In tympanoplasty surgeries, the head and neck remain in a lateral position, and venous return in the surgical field may sometimes be compressed due to the procedure. The aim of this study is to determine the effect of lateral head position and variables such as demographic data and surgical duration on increased intracranial pressure. Methods: Patients over 18 years of age, classified as asa ı and ıı, undergoing tympanoplasty surgery under general anesthesia in the lateral head and neck position will be included in the study. Patients' vital signs (arterial blood pressure, heart rate, spo2, and etco2) will be monitored regularly in the operating room before and after surgery. Demographic data (age, gender, weight, height), surgery duration, and postoperative complications will also be recorded. Anesthesia will be administered with 2-4 mg/kg propofol, 0.6 mg/kg rocuronium, and 1-2 mcg/kg fentanyl for induction, and sevoflurane for maintenance. Following intubation, onstitial lateral head and neck (onsd) measurements will be taken by the anesthesiologist at three time intervals (in transverse and sagittal planes). Both onsds will be recorded by ultrasound: T1: 5 minutes in the supine position, T2: at the end of the procedure with the head in the lateral posit