In the dexmedetomidine group, dexmedetomidine is administered at a rate of 0.5 μg/kg/h immediately after anesthesia induction and continued until the completion of the surgery.

In the control group, a 0.9% normal saline infusion is initiated at the same rate immediately after anesthesia induction and continued until the end of the operation.

In the dexmedetomidine group, dexmedetomidine is administered at a rate of 0.5 μg/kg/h immediately after anesthesia induction and continued until the completion of the surgery. The research nurse, who did not participate in the study other than the management and preparation of the study medication, prepared 50mL of 0.9% normal saline for the control group and a mixture of dexmedetomidine 2 mL and 0.9% normal saline 48 mL (at a concentration of 4 μg/mL) for the dexmedetomidine group.

the actual secretion levels of catecholamines, specifically epinephrine and norepinephrine, were measured at different time points