2.4. Procedures
nerve block, upper gastrointestinal tract
The patients were brought into the operation room, where the anesthesiologist connected the patient to a patient monitor (Biolight Anyview P22, Guangdong Biolight Meditech Co. Ltd., Zhuhai) to monitor the blood oxygen saturation, noninvasive blood pressure, bispectral index, and 3 lead continuous electrocardiography. Once the patients were connected to a patient monitor, an infusion line was placed to administer crystalloid infusion 5 mL/kg and penehyclidine hydrochloride 0.01 μg/kg bolus, followed by dexamethasone 10 mg bolus, and dexmedetomidine 0.5 µg/kg for 10 minutes, after which a blood pressure reading was recorded, this timestamp was labeled T1, followed by a continuous infusion of dexmedetomidine 0.2 μg/kg/h, until the gastric tissue resection, for sedation.After the initial preparation procedures, the process of induction began, and the anesthesiologist unknowingly administered a placebo to the control group and the esketamine to the esketamine group; the following procedures were identical among the 2 groups.A bolus dose of anesthetic drugs i.e., midazolam 0.03 mg/kg, sufentanil 0.3 μg/kg, etomidate 0.2 mg/kg, propofol 1 mg/kg, and rocuronium bromide 0.9 mg/kg were administered. Following this, when induction drugs began effect, a second blood pressure measurement was taken right before intubation; this timestamp was labeled as T2. Then, 1 minute and 5 minutes after intubation, 2 readings were taken, and the timestamps were labeled as T3 and T4, respectively. Then, a target-controlled infusion of propofol, remifentanil, and sevoflurane, which were adjusted with objective monitoring BIS, maintaining it between 40 to 60, followed by nerve block, that is, 10 mL of 0.5% ropivacaine for the bilateral rectus abdominalis sheath block and 0.25% ropivacaine 20 mL for the unilateral right transversalis fascia block administered locally. The patients then underwent gastroscopy to evaluate their upper gastrointestinal tract and identify any potential issues or abnormalities before proceeding with bariatric surgery.Three blood pressure readings were taken at the time of incision, 1 minute after incision and 5 minutes after incision; these timestamps were labeled T5, T6, and T7, respectively. 5 mg of tropisetron hydrochloride and 0.1 mg/kg of oxycodone was administered following gastric tissue resection. After the surgical procedure was concluded, anesthetic drugs were discontinued at the same time as suturing, which was followed by extubation, and patients were transferred to the postanesthesia care unit and then transferred to the general ward. All drugs administered based on body weight were titrated according to the adjusted body weight of the patients.