Data acquisition
blood loss
BLOOD LOSS, SECONDARY, ADVERSE REACTIONS
Baseline patient characteristics (age, gender, body mass index (BMI), ASA physical status, muscle strength), operation time, blood loss, fluid replacement, urine volume, and body temperature were all recorded. T0 was before anesthesia induction, T1 was after anesthesia induction and before Dex infusion, T2 was 10 min after Dex administration, T3 was 20 min after Dex administration, and T4 was 30 min after Dex administration (T4). The HR and MAP were recorded at T0, T1, T2, T3, and T4. The primary endpoint was the incidence of positive cases of tcMEPs. The secondary endpoints included the latency and amplitude of SEPs at T1, T2, T3, T4, and the incidence of positive cases of SEPs, the propofol and remifentanil dosages, the occurrence of perioperative adverse reactions.