Anesthesia Induction

Ciprofol is a novel intravenous anesthetic with a pharmacological profile similar to propofol but with a lower incidence of injection pain, hypotension, and respiratory depression. For pediatric day-case surgeries, laryngeal mask airway (LMA) insertion without neuromuscular blockers is increasingly preferred. While opioids are often combined with hypnotics to optimize insertion conditions, the optimal bolus dose of ciprofol when co-administered with a standard dose of fentanyl for LMA insertion in children remains unknown. This study aims to determine the 95% effective dose (ED95) of a single intravenous bolus of ciprofol, combined with a fixed dose of fentanyl (1 μg/kg), for successful LMA insertion in children aged 1-12 years during general anesthesia induction.

This study will enroll children ages 2-6 who are undergoing an elective outpatient surgical procedure under general anesthesia. They will be randomized to one of the following groups and assessed for preoperative anxiety, mask acceptance, and behavioral changes in the following week. 1. darkened room and star projector with parental presence; 2. preoperative midazolam 0.5 mg/kg by mouth and parental presence; or 3. parental presence alone.

This is a prospective, single-center, randomized, double-blind controlled trial involving patients scheduled for elective surgery requiring general anesthesia with propofol induction. Participants are randomly assigned to one of three groups: the ondansetron group (8 mg IV), the lidocaine group (40 mg IV), or the control group (0.9% normal saline placebo). Study medications are administered intravenously over 5 minutes, ending 1 minute before anesthetic induction. the goal: To assess the efficacy of intravenous ondansetron versus lidocaine and placebo in reducing the incidence and intensity of pain associated with propofol injection in patients undergoing general anesthesia.

Within 30 minutes before anesthesia, acupoint electrical stimulation at different frequencies were applied at Neiguan, Jian Shi, and Baihui. The changes in blood pressure during the anesthesia induction period were compared between the high-frequency group and the low-frequency group.

The purpose of this study is to evaluate whether the administration of 5 ml/kg of colloid solution prior to anesthesia induction, compared with 5 ml/kg of lactated Ringer's solution, can reduce hemodynamic fluctuations during the induction period (defined as the first 15 minutes after induction) in patients undergoing Transcatheter Aortic Valve Replacement (TAVR).

The goal of this clinical trial is to compare the performance difference between trained model and clinical professionals in anesthesia control during gastrointestinal endoscopy. The participants would include adults aged between 18-65 years old with ASA scores I-II. The main questions it aims to answer are: * Can AI model successfully and safely perform anesthesia during gastrointestinal endoscopy? * Researchers hypothesis that anesthesia performed by professionals is not inferior to those performed by AI model. The researchers will compare the results of the AI group with the traditional group to see if both groups have similar success rates in performing anesthesia. Participants will fast for 8 hours before the procedure, and drinking water will be prohibited for 2 hours after taking the intestinal purgatives.

This study aims to determine whether performing a paravertebral nerve block at the superficial surface of the superior costotransverse ligament (SCTL) (without needle penetration of the SCTL) is more effective in maintaining hemodynamic stability during the induction phase of thoracoscopic lung lobectomy compared to the deep surface of the SCTL (with needle penetration of the SCTL). This is a multicenter, double-blind, randomized controlled trial enrolling a total of 168 participants across five hospitals. To investigate the effects of different nerve block methods on hemodynamics during induction, participants will be allocated to either the deep plane SCTL block group (T group) or the superficial plane SCTL block group (S group) using a stratified randomization scheme. The stratification accounts for a 40% proportion of hypertensive patients within each treatment group at each center. Thirty minutes before surgery, patients will receive either an ultrasound-guided deep SCTL block (needle penetrating the SCTL) or a superficial SCTL block (needle not penetrating the SCTL) in the pre-anesthesia room. The target vertebral levels for the block are T4 and T6, and 20 mL of 0.375% ropivacaine hydrochloride solution will be injected slowly at each site. Researchers will document whether subpleural compression is observed on ultrasound imaging and monitor for complications such as hemothorax, pneumothorax, local hematoma, local anesthetic toxicity, epidural anesthesia, or total spinal anesthesia during the procedure. Another investigator, blinded to the group allocation, will evaluate patients after the nerve block procedure, recording any occurrences of hemothorax, pneumothorax, local hematoma, local anesthetic toxicity, epidural block, or total spinal anesthesia. Cold sensitivity tests using the temperature method will be conducted at the midaxillary line within the corresponding blocked regions at 5, 10, 20, and 30 minutes post-block, and the sensory blockade level will be recorded. Thirty minutes after the block, anesthesia induction will be performed using target-controlled infusion (TCI) of propofol and remifentanil, along with rocuronium (0.6 mg/kg). Heart rate (HR), mean arterial pressure (MAP), stroke volume (SV), cardiac index (CI), and stroke volume index (SVI) will be measured every minute from induction until 5 minutes after intubation. Hypotension is defined as a MAP decrease of 20% or an absolute MAP \< 65 mmHg, while severe hypotension is defined as a MAP decrease of 30% or an absolute MAP \< 55 mmHg. Hemodynamic stability will be maintained using vasoactive medications as needed. The study will record intraoperative consumption of propofol and remifentanil, anesthesia duration, intraoperative intravenous fluid volume, urine output, blood loss, and extubation time. Postoperative assessments will include resting and movement-evoked (coughing) VAS scores at 4 and 24 hours, opioid consumption within 24 hours (oxycodone usage, first demand time, number of effective and actual demands), and additional analgesic requirements. The QOR-15 score at 24 hours and puncture-related complications within 72 hours postoperatively will be documented, along with a patient satisfaction survey at 72 hours. For the imaging study evaluating drug diffusion following each block method using CT (3D) imaging, 40 patients will be recruited at Nanjing First Hospital. Patients requiring preoperative CT-guided localization and puncture will receive an ultrasound-guided deep SCTL block (T group) or superficial SCTL block (S group) 30 minutes before the procedure, with 10 patients in each group. The block sites will be at the surgical side T4 and T6 levels, using 20 mL of a nerve block solution containing 0.375% ropivacaine mixed with 2 mL of iohexol (total 20 mL). Following the nerve block, patients will be placed in the supine position, and after 30 minutes, a blinded investigator will assess sensory loss using cold stimulation at the anterior chest wall (midclavicular line), lateral chest wall (posterior axillary line), and posterior chest wall (paravertebral region). Subsequently, patients will undergo routine CT-guided lesion localization and 3D imaging technology will be used to evaluate drug diffusion patterns for the two block techniques. Any adverse events occurring during the trial will be managed according to the study protocol and recorded accordingly.

Immediately following the induction of general anesthesia, arterial hypotension may occur with an incidence of about 40% in patients classified as ASA 3 or 4. Perioperative arterial hypotension is associated with increased perioperative morbidity and mortality. The increased mortality associated with perioperative arterial hypotension has been reported up to 30 and 90 days after surgery. This association appears to be both dose-dependent and time-dependent (severity and duration of arterial hypotension). EchOptimal study aims to determine whether non invasive preoperative stroke volume optimization using transthoracic echocardiography (TTE) can reduce the incidence and severity arterial hypotension following induction of general anesthesia. This is prospective, randomized, controlled, double blinded study approved by ethics comittee. The primary objective of this study is to compare the incidence of arterial hypotension (mean arterial pressure \< 65 mmHg) within the first 15 minutes following the induction of general anesthesia, between 2 groups : * standard current care (stroke volume optimized after induction of general anesthesia using oesophageal doppler) and * preopertaive stroke volume optimization using transthoracic echocardiography measument of subaortic velocity time integral.