This prospective study involves assessing neurocognitive function in patients undergoing laparotomic gastrointestinal surgery. Mini Mental state Assessment test and Mini-Cog tests will be conducted at multiple intervals preoperatively and postoperatively. Anesthesia management, vital signs, drug consumption, and blood gas values will be recorded throughout the surgery. After all neurocognitive evaluations of the patients are performed at planned intervals for 1 week, the levels of dexmedetomidine and remifentanyl consumed by the patients in the peroperative period will be determined from the anesthesia follow-up sheet and the total duration and amount used will be recorded. At the end of the study, the relationship between neurocognitive values and dexmedetomidine will be compared.

All results of laparotomic gastrointestinal surgery that meet the inclusion criteria of the preoperative anesthesia evaluation process will be determined, and the neurocognitive evaluations, mini mental state assessment test and Mini-cog test will be delivered to all these patients by the anesthesiologist doctor 24 hours before the preoperative period. These two tests will be repeated by the same doctor in the preoperative waiting room on the day of the operation.

From the preoperative waiting room, patients will be taken to the operation room after premedication with 2mg midazolam. After patients are monitored with standard American Society of Anesthesia monitoring (Heart rate (HR), peripheral saturation, non-invasive artery pressure monitoring), patient state index(PSI), the first values will be recorded before surgery. During induction, 1-2mg/kg propofol, 2mcg/kg Fentanyl and 0.8mg/kg rocuronium will be administered and then the patient will be intubated. Patients will be monitored to be normothermic by body temperature monitoring, and Sevoflurane anesthesia will be maintained at 1 Minimal alveolar concentration level as inhalation anesthesia. Patient state index value will be kept between 40-60%. During the peroperative period, non-invasive arterial pressure values, saturation values, heart rate, body temperature values will be recorded on the follow-up form as preoperative, at the beginning of the operation, at 30-minute intervals from the beginning of the operation, and before and after extubation at the end of the operation. If the anesthesiologist starts remifentanyl and dexmedetomidine infusion to the patients during the surgery, when it started and at what dose will be noted on the anesthesia chart. The anesthesiologist performing the neurocognitive evaluation will not be aware of this. The decision whether to start these medications will depend on the relevant anesthesiologist's decision regarding the patient's specific anesthesia management, regardless of the study.

Heart rate, peripheral saturation, non-invasive artery pressure values will be recorded upon entering and exiting the postoperative recovery unit. The patients' total bleeding amount, amount and type of intravenous fluid administered, and blood gas values will be recorded throughout the surgery.

Postoperative pain monitoring will be done with the Numerical Pain Rating Scale, and in patients with an Numerical pain rating scale score greater than 4, Tramadol will be given 100mg every 6 hours, Nonsteroidal anti-inflammatory 100mg every 8 hours, and paracetamol 1000mg every 6 hours will be given intravenously if necessary.

Mini mental state assessment test and Mini-cog test will be repeated in all patients by the anesthesiologist just before being transferred from the postoperative recovery unit to the ward and at the 24th hour, 3rd day, and 5th postoperative day.

After all neurocognitive evaluations of the patients are performed at planned intervals for 1 week, the levels of dexmedetomidine and remifentanyl consumed by the patients in the peroperative period will be determined from the anesthesia follow-up sheet and the total duration and amount used will be recorded.

Anesthesia management of patients during the preoperative and peroperative periods will be planned and implemented as deemed appropriate by the anesthesiologist who follows the patient during the surgical period, regardless of this planned study. The researcher performing the neurocognitive evaluation will not have any intervention or knowledge in these processes. The reason why this study was planned prospectively is that neurocognitive evaluation will be performed prospectively for 1 week. There is no intervention in the patient's anesthesia management and medications, or in the grouping of patients and their treatment. At the end of the study, the relationship between neurocognitive values and dexmedetomidine will be compared.

Inclusion Criteria:

• Patients aged 18-65 who will undergo laparotomic lower and upper gastrointestinal system surgery

Exclusion Criteria:

• American society of anesthesia of 4-5 patients
• Patients without voluntary consent
• Patients with previous surgery or vertebrobasilar insufficiency
• Patients with Carotis stenosis
• Patients with a visual analog scale above 4 in the postoperative recovery unit
• Patients whose cerebral oxygenation decreased by 15% from the beginning in cerebral oximetry monitoring during the perioperative period
• Patients with bleeding that disrupts hemodynamics during follow-up and bleeding greater than 20% of body volume
• Patients with postoperative intensive care unit follow-up
• Patients with a decrease of more than 20% from the baseline systolic value (based on ward monitoring) during follow-up
• Patients with intraoperative ventilation failure, patients with hypercarbia, hypocarbia
• Patients whose Patient State Index value falls below 25, which is sufficient for the depth of anesthesia, during anesthesia induction or maintenance.
• Patients with known neurological, psychiatric, unstable cardiovascular, renal or hepatic system disease
• Patients with Uncontrolled Hypertension
• Patients with greater than 1st degree heart block
• Patients allergic to α2 adrenergic receptor agonist
• Patients who cannot speak and do not know Turkish
• Alcohol and substance addicted patients
• Patients who have used opioids in the last 24 hours
• Patients who developed sepsis during postoperative follow-up
• Patients with a history of recurrent surgery

Patients who will undergo laparotomic lower and upper abdominal surgery will constitute the patient groups of this study. Patients who will be operated on due to early stage gastrointestinal tumor will constitute the study population. Among these patients, those without neurological disorders will be included in the study.