This study aims to evaluate changes in perfusion index (PI) in pediatric patients undergoing elective surgery under low-flow anesthesia. PI will be monitored at multiple intraoperative and postoperative time points to assess its relationship with hemodynamic stability and depth of anesthesia. The study will also investigate whether low-flow anesthesia affects the incidence of emergence agitation (EA). Patients will be assigned to either low-flow or normal-flow anesthesia groups based on routine clinical practice. No intervention will be applied beyond standard care. The findings are expected to provide insight into the predictive value of PI in postoperative recovery and support safer anesthesia practices in pediatric populations.

Inclusion Criteria:

• ASA I-II pediatric patients
• Age 2 to 12 years
• Undergoing elective surgery lasting between 1-6 hours
• Informed consent obtained from parents/guardians

Exclusion Criteria:

• Cardiovascular, respiratory, neurological, metabolic, or endocrine disorders
• Premature birth with corrected age < 2 years
• Obesity or severe malnutrition (BMI <5th or >95th percentile)
• Psychiatric or neurodevelopmental disorders (e.g., autism)
• Malignant hyperthermia or hypersensitivity to anesthetics
• Emergency surgeries
• Lack of IV access requiring inhalational induction
• Contraindications to low-flow anesthesia including:
• Severe pulmonary disease
• Congenital heart disease with shunt physiology
• Anticipated high oxygen demand
• Airway obstruction risk
• Surgeries requiring high gas flow or >6 hours duration

Group allocation is determined by the anesthesia provider during routine care. Both the participant and the outcome assessor are blinded to group assignment. Data analysis is performed without group identifiers.