The goal of this clinical trial is to compare two medicines used to induce general anesthesia in adults undergoing elective laparoscopic cholecystectomy. The study aims to determine whether remimazolam leads to a different time to loss of consciousness than propofol.
The main question it aims to answer is: Does remimazolam change the time to loss of consciousness compared with propofol during anesthesia induction?
Researchers will compare remimazolam with propofol to evaluate the time required for participants to lose consciousness. The study will also compare blood pressure, heart rate, and other safety outcomes during anesthesia induction.
Participants will:
* Be randomly assigned to receive either remimazolam or propofol for anesthesia induction. * Receive standard monitoring and anesthesia care throughout surgery. * Have their time to loss of consciousness, vital signs, and any adverse events recorded during the induction period.
Patients aged 18 years or older.
American Society of Anesthesiologists (ASA) physical status I or II.
Scheduled to undergo elective laparoscopic cholecystectomy under Total Intravenous Anesthesia (TIVA).
Patients younger than 18 years or older than 50 years
American Society of Anesthesiologists (ASA) physical status III to V
Body Mass Index (BMI) < 17.5 kg/m² or > 30 kg/m²
Hemodynamically unstable patients
Parallel
Remimazolam
DrugLyophilized powder reconstituted for intravenous injection. Administered via an electronic infusion pump at a fixed continuous induction rate of 6 mg/kg/h until clinical benchmarks are achieved. Maintenance is sustained at a baseline continuous infusion rate of 1 mg/kg/h. To ensure a strictly standardized anesthetic baseline, all patients receive a uniform, weight-based co-administration of intravenous fentanyl and a neuromuscular blocking agent at induction, followed by a continuous intraoperative analgesic infusion of remifentanil via target-controlled infusion (TCI) guided by the Minto model (effect-site targeting). Maintenance remimazolam doses are precisely titrated based on real-time bispectral index (BIS) values to target a depth of anesthesia between 40 and 60.
Propofol
DrugIntravenous 1% lipid emulsion formulation of propofol. Administered via an automated target-controlled infusion (TCI) system programmed with the Marsh pharmacokinetic model. Induction is initiated at a fixed effect-site target concentration of 4 mcg/mL. To ensure a strictly standardized anesthetic baseline, all patients receive a uniform, weight-based co-administration of intravenous fentanyl and a neuromuscular blocking agent at induction, followed by a continuous intraoperative analgesic infusion of remifentanil via target-controlled infusion (TCI) guided by the Minto model (effect-site targeting). Maintenance propofol infusion rates are dynamically adjusted to maintain an objective bispectral index (BIS) within the 40-60 range.
Time to Loss of Consciousness (TLOC)
The duration, measured in seconds, from the exact initiation of the intravenous hypnotic agent infusion (either remimazolam or propofol) until the participant achieves clinical loss of consciousness. Loss of consciousness is strictly defined as the co-occurrence of two clinical criteria: the complete loss of response to a standardized verbal command (calling the patient's name aloud) and the absence of the eyelash/palpebral reflex (córneo-palpebral reflex), assessed continuously during the anesthesia induction phase.
Incidence of Anesthesia-Induced Hypotension
Percentage of participants experiencing at least one episode of hypotension. Hypotension is operationally defined as a decrease in blood pressure of more than 20% from the participant's documented baseline value, or a mean arterial pressure (MAP) lower than 65 mmHg.
Incidence of Perioperative Adverse Events
Proportion of participants experiencing specific anesthesia-related adverse events, including bradycardia (heart rate \< 50bpm), episodes of apnea within the Post-Anesthesia Care Unit (PACU), or any clinical event requiring unplanned therapeutic interventions.
Incidence of Early Postoperative Delirium
Percentage of participants with delirium at discharge from the Post-Anesthesia Care Unit (PACU), assessed using the 4AT (4 A's Test), a validated rapid screening tool for delirium.
Bispectral Index (BIS) Values at Key Anesthetic Milestones
Objective tracking of depth of anesthesia using bispectral index (BIS) values (measured on a scale from 0 to 100, where 100 indicates fully awake and 0 indicates flat-line EEG). Continuous values will be extracted and compared at specific clinical time points: at the initiation of induction, during laryngoscopy, and periodically throughout the intraoperative period.
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Universidade Federal de Sergipe
Lead sponsor
Cristália Produtos Químicos Farmacêuticos Ltda.
Collaborator
