2.5. Procedures
NCD, hypertension, hypotension
VASODILATION, HYPERTENSION, COLD
After entering the operating room, HR and rhythm were monitored using a 3-lead electrocardiogram, noninvasive BP was monitored using an arm cuff, and peripheral oxygen saturation was recorded for all participants. Vital signs were recorded every 2 minutes for 30 minutes after the SA. Prior to SA, 5 mL/kg crystalloid was rapidly administered to prevent hypotension due to peripheral vasodilation. For the SA, hyperbaric bupivacaine 0.5% was injected intrathecally using a 25G spinal needle with an interlaminar approach in the lateral position. The dose of bupivacaine was within the range of 11 to 14 mg, according to the patient’s height and expected operation time. The patient was placed supine, and the complete loss of cold or light touch sensation determined the level of blockage. Once the blockage level was fixed, DEX (1 μg/kg) was administered intravenously (IV) to both groups at the loading dose for 10 minutes. The starting time point for the study was set at 0 minute when the DEX loading dose was initiated after SA. After 5 minutes of loading dose administration, 1 researcher (S.K.) confirmed the group assignment and the dose of NCD (60 μg/mL) at 5 μg/kg was administered within 5 minutes in the DEX-NCD group. In the DEX (control) group, an equal volume of normal saline was infused IV as a placebo. After infusion of the loading dose for 10 minutes, the DEX dose was changed to a maintenance dose of 0.5 μg/kg/h. The infusion device used in both groups was the TERUFUSIONIntraoperative hypotension and hypertension were defined as changes in systolic BP of >20% from baseline. In the case of hypotension, we planned to administer a vasoconstrictor or inotropic agent, depending on the situation; in the case of hypertension, NCD or a beta-blocker was administered. At the end of the surgery, fentanyl-based (0.35 μg/kg/h) IV patient-controlled analgesia was administered to both groups until POD 2.