Subcostal TAP Block and EEG Dynamics in Laparoscopic Cholecystectomy

Laparoscopic cholecystectomy is a commonly performed minimally invasive surgical procedure. Despite its minimally invasive nature, surgical stimulation and pneumoperitoneum may cause pain-related physiological and neurophysiological responses during general anesthesia. This prospective observational study will evaluate patients undergoing laparoscopic cholecystectomy under general anesthesia. Patients will be observed according to the analgesic technique selected by the attending anesthesiologist as part of routine clinical care: intravenous remifentanil alone or remifentanil combined with an ultrasound-guided subcostal transversus abdominis plane (TAP) block. The study will examine the relationship between the use of subcostal TAP block and intraoperative analgesic requirements, Bispectral Index (BIS) values, electroencephalographic (EEG) dynamics, and burst suppression. Postoperative pain scores, additional analgesic requirements, quality of recovery, mobilization time, length of hospital stay, and patient satisfaction will also be evaluated.

Inclusion Criteria: * Age 18 years or older * American Society of Anesthesiologists (ASA) physical status I-III * Scheduled to undergo laparoscopic cholecystectomy under general anesthesia * Written informed consent provided by the participant or, when applicable, the legally authorized representative Exclusion Criteria: * Refusal to participate in the study * American Society of Anesthesiologists (ASA) physical status IV-V * Known allergy or hypersensitivity to medications used during perioperative anesthetic or analgesic management