The Effect of Neostigmine and Sugammadex on the Optic Nerve Sheath Diameter

Comparison of the Effects of Neostigmine and Sugammadex on the Optic Nerve Sheath Diameter During the Postoperative Extubation Period

This study will compare how two drugs, sugammadex and neostigmine-used to reverse muscle relaxation after surgery-affect the size of the optic nerve sheath (the nerve behind the eye) as patients wake up and have their breathing tubes removed. It will also examine the relationship between changes in blood pressure and heart rate during this time and these measurements. This study will be conducted on 86 healthy patients aged 18-65 who will undergo planned surgery at the Çukurova University Faculty of Medicine, Department of Anesthesiology and Reanimation. Patients will be randomly divided into two groups: the sugammadex group and the neostigmine group. All patients will receive standard general anesthesia and rocuronium to relax their muscles. At the end of the surgery, to reverse this effect, patients will be given either sugammadex or a mix of neostigmine and atropine. Group S will receive 2 mg sugammadex per kg, while Group N will receive 0.05 mg neostigmine and 0.02 mg atropine per kg. The width of the optic nerve sheath will be measured by ultrasound 5 minutes after the breathing tube is inserted, 5 minutes before the tube is removed, and 5 minutes after it is removed. Additionally, blood pressure, heart rate, and any complications during the surgery will be tracked and compared between the groups.

The study will be conducted prospectively, randomly, and double-blind on a total of 86 patients aged 18-65 years, classified as ASA 1-2, undergoing elective surgery at the Department of Anesthesiology and Reanimation, Faculty of Medicine, Çukurova University. Written and verbal informed consent will be obtained from all participants prior to the study.

The demographic data, such as age, gender, body weight, and height, as well as ASA score and information on comorbidities, will be recorded for the patients included in the study in the preoperative anesthesia care unit. All patients who will be taken to the operating room without premedication will undergo routine monitoring, including electrocardiography, noninvasive blood pressure monitoring, and peripheral oxygen saturation. During induction of anesthesia, propofol IV 2 mg/kg, rocuronium IV 0.6 mg/kg, and fentanyl IV 1 mcg/kg will be used. After observing adequate muscle relaxation with a TOF (Train-of-Four) monitor, tracheal intubation will be performed. All patients will receive mechanical ventilation after intubation. During anesthesia, a gas mixture of 2% sevoflurane, 60% nitrous oxide, and 40% oxygen will be administered at a flow rate of 2 L/min. To maintain muscle relaxation throughout the surgery, when a TOF of 2 is observed, 0.2 mg/kg of rocuronium IV will be administered. Tramadol 2 mg/kg IV will be given 45 minutes before the end of surgery for postoperative pain management. Ondansetron 8 mg IV will be planned as antiemetic treatment. At the end of the surgery, the maintenance gases will be discontinued, and according to the randomization, the anesthesiologist responsible for anesthesia administration will either administer 2 mg/kg Sugammadex IV or 0.05 mg/kg Neostigmine IV plus 0.02 mg/kg atropine sulfate IV. Patients who show a TOF value of 90% and clinically adequate respiration will be extubated.

In addition to the anesthesiologist responsible for administering anesthesia, one blinded evaluator for each group will perform three ultrasound measurements on both eyes to determine the Optic nerve sheath diameter at 5 minutes after endotracheal intubation, 5 minutes before extubation, and 5 minutes after extubation. The measurements will be recorded while the patient is in a supine position, with ultrasound gel applied to the eyelid, using a linear probe without applying pressure to the eyeball.

The diameter of the optic nerve sheath will be systematically measured at a point 3.0 mm posterior to the optic disc to ensure consistent anatomical evaluation.

Inclusion Criteria:

• With an ASA physical status of 1-2
• Patients scheduled for elective surgery
• Patients willing to participate in the study

Exclusion Criteria:

• Patients with heart, liver, kidney, or respiratory failure
• Brain tumors, hemorrhages, or aneurysms
• Patients who have undergone eye, cardiovascular, or neurosurgery
• Eye or neurological diseases or increased intracranial pressure
• Laparoscopic surgeries
• Cases not in the supine position
• Allergy to the medications used
• Patients who did not provide informed consent to participate in the study.