Time to Loss of Consciousness With Remimazolam Versus Propofol for Anesthetic Induction in Laparoscopic Cholecystectomy

General anesthesia can be induced with several intravenous hypnotic agents. Propofol remains a standard choice due to its rapid onset and predictable clinical effect; however, it is frequently associated with dose-dependent cardiovascular depression. Remimazolam, an ultra-short-acting benzodiazepine, represents an alternative with a distinct metabolic pathway via tissue esterases, potentially offering greater hemodynamic stability. Nonetheless, current literature comparing induction kinetics between these two pharmacological strategies exhibits high heterogeneity, often driven by variations in drug delivery methods and mixed surgical profiles.

To improve the internal validity of these clinical comparisons, this protocol restricts the evaluation to a single, specific surgical model. Narrowing the clinical environment to a uniform surgical procedure eliminates major confounding variables-such as widely divergent operational durations, patient positioning dynamics, unexpected blood loss, and varying baseline nociceptive stimuli-which typically complicate broader, multi-procedural anesthesia trials.

Furthermore, because the physical characteristics of the study medications preclude complete investigator masking during drug administration, specific operational safeguards are built into the clinical workflow. Anesthesia delivery during the induction phase relies entirely on pre-specified, automated delivery algorithms (comparing a fixed-rate continuous infusion against a pharmacokinetic target-controlled model) rather than subjective, clinician-guided titration. Utilizing fixed algorithmic delivery protocols prevents clinical preferences from influencing drug administration, thereby controlling for potential execution bias.

Following the induction phase, physiological tracking and depth-of-anesthesia monitoring are managed through objective, automated indices to ensure that post-induction adjustments remain standardized across both evaluation groups. This structured approach ensures that the resulting clinical observations reflect the distinct pharmacological and pharmacokinetic profiles of the selected hypnotic strategies rather than confounding clinical management choices.

Inclusion criteria

• 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).

Exclusion criteria

• 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
• Altered or impaired renal or hepatic function
• Neuromuscular disorders
• History of alcohol or drug dependence
• History of allergy or hypersensitivity to any of the anesthetic medications utilized in the protocol