Some changes in the patient's cognitive state are observed during the recovery period from general anesthesia. This period of behavioral dysregulation has been called emergence agitation (EA) and emergence delirium (ED). ED and EA occur in the early postoperative period (often within the first 30 minutes). The incidence of ED ranges from 10% to 80% in children and is described as a distressing clinical condition by 42% of pediatric anesthesiologists. Self-harm by the child increases the risk of delayed discharge and may increase the cost of medical care.

Sevoflurane is a widely used agent for the induction and maintenance of anesthesia, but its use is associated with the occurrence of ED in the pediatric population. Clinical findings are characterized by hallucinations, struggling, restlessness, crying, and disorientation.

In the literature, the Pediatric Anesthesia Rescue Delirium (PAED) Scale Score is used in the diagnosis of ED and EA. This score consists of 5 criteria (maximum score 20) scored using 0-4 point scales. These criteria; The child needs to make eye contact with the caregiver, the child's movements are purposeful, the child is aware of the environment, the child is restless/angry, the child cannot be consoled. While the sensitivity of ≥10 points for the diagnosis of ED is 64% and the specificity is 86%, the sensitivity of >12 points for the diagnosis of ED is 100% and the specificity is 94.5%.

Monitoring intraoperative depth of anesthesia in the adult population has been recommended by the American Society of Anesthesiologists (ASA) due to its potential benefits such as faster recovery time and lower drug dosage, as well as prevention of adverse effects such as the incidence of hypotension. The use of anesthesia depth monitors used so far for children is controversial because brain development in children has not yet been completed and the calculation algorithms of these indices are based on adult EEG characteristics.

There are very few studies in the literature on the relationship between anesthesia depth monitoring and EA/ED in children, and further studies are needed.

During the compilation period after general anesthesia, cognitive status changes called emergence agitation and emergence delirium, clinically characterized by hallucinations, struggling, restlessness, crying, and disorientation, are observed. ED and EA often occur in the early postoperative period (especially in the first 30 minutes).

Sevoflurane is a widely used agent for the induction and maintenance of anesthesia, but its use is associated with the occurrence of ED/EA in the pediatric population. In our study, we aimed to determine the effect of sevoflurane anesthesia on the incidence of ED/EA under anesthesia depth monitoring.

Patients who give informed consent will be divided into 2 groups and randomized using the opaque sealed envelope method.

Children participating in the study will be evaluated with mYPAS, an anxiety assessment scale, in the preoperative period. Studies have found that children with high levels of anxiety have a higher frequency of developing maladaptive behavioral changes, pain, and ED after surgery.

On the day of surgery, patients will be taken to the operating room after premedication with 0.5 mg/kg po midazolam. Following routine noninvasive blood pressure, saturation and ECG monitoring; PEEG monitoring will be carried out with the help of pediatric sensors. Anesthesia guided by PEEG (processed electroencephalography) contributes to optimal targeting of the depth of anesthesia. The rationale for PEEG is to provide a simplified method for monitoring the depth of anesthesia through rapid interpretation of the frontal electroencephalogram (EEG). Thus, 4-channel raw EEG (L1, R1, L2 and R2 - equivalent to Fp1, F7, Fp2 and F8 according to the standard EEG monitoring system), electrode impedance, patient condition index (PSI), left and right spectral edge frequency (SEF95) and burst suppression ratio (SR) can be achieved. PSI; It is a dimensionless depth of anesthesia index that combines "weighted quantitative EEG parameters reflecting multiple dimensions of brain electrical activity." The correct depth of anesthesia is determined by the PSI value between 25 and 50.

Following inhaler induction with 8% sevoflurane, 0.5 mg/kg rocuronium and 2 mcg/kg fentanyl will be administered iv. Anesthesia maintenance of the patients will be provided with sevoflurane and 0.02-0.1mcg/kg/min remifentanil iv infusion.

To the control group; As we apply in routine anesthesia practice, sevoflurane anesthesia will be applied with Endtidal agent consumption of 0.8 MACage for MACage:1 with 2 standard deviations. During the surgery, parameters indicating the depth of anesthesia will be placed away from the anesthesiologist and closed to ensure blindness. At the end of the surgery, the data will be received via USB.

As for the working group; Sevoflurane anesthesia will be applied by adjusting the MAC so that the PSI median value remains between 25-50 (if PSI<25, MAC will be reduced by 0.1, if PSI>50, MAC will be increased by 0.1).

At the end of inhalation anesthesia, regional anesthesia (peripheral nerve/body block) will be applied to both groups for postoperative analgesia.

At the end of the operation, the PAED scores of all children 5, 15 and 30 minutes after extubation will be evaluated and recorded by PACU (post-anesthesia care unit) nurses who are blind to the study groups.

Ped-PADSS score, defined as the discharge score, will be checked at 30, 45 and 60 minutes in the compilation room. This score consists of 5 criteria which are vital signs, activity level, nausea-vomiting, presence of pain (<6 years OPS, >6 years VAS) and surgical bleeding. It is evaluated between 0 and 10 points, 9 points and above are safe for discharge from the compilation room.

In the post-hospital discharge period, the PHBQ scale will be administered to patients via an online survey on days 3, 14 and 28. This scale is a post-discharge behavior scale developed for children, consisting of six subscales (general anxiety, separation anxiety, sleep, eating, aggression, apathy) and 27 questions. Values between 27-135 points will be recorded and evaluated in terms of whether late-term behavioral changes occur.

There is little data in the literature on the relationship between anesthesia depth monitoring and ED during recovery in children, and further studies are needed. In our study, we think that the frequency of ED will be less in the study group than in the control group.

Inclusion Criteria:

• 2 to 8 years old
• Surgery time > 1 hour
• Urology, Plastic Surgery and Pediatric Surgery patients

Exclusion Criteria:

• Patients with neuromotor development abnormalities
• Patients with a history of epilepsy/antiepileptic treatment
• Patients receiving intraoperative ketamine administration
• Patients requiring postoperative ICU admission
• Surgeries performed under emergency conditions
• Patients without parental consent