Comparison of the Effects of Desflurane-Remifentanyl and Propofol-Remifentanyl Anesthesia on Intraoperative Cerebral Oxygenation in Patients Undergoing Laparoscopic Cholecystectomy

Study Population:

Patients undergoing elective laparoscopic cholecystectomy under general anesthesia will be included.

Study Design:

This is an observational study. No interventions outside routine clinical practice will be applied. All procedures will be performed by experienced anesthesiologists according to standard institutional protocols.

Data Collection

Preoperative Data:

The following variables will be recorded from anesthesia charts:

Demographics: age, sex, height, weight, body mass index (BMI) Education level Smoking, alcohol, and substance use status Routine preoperative laboratory tests

Clinical scores:

Charlson Comorbidity Index (CCI) Beck Anxiety Scale ARISCAT Score STOP-BANG Score Montreal Cognitive Assessment (MoCA) ASA Physical Status Classification

Intraoperative Data:

Patients will be observed in two groups based on anesthesia technique:

Desflurane + remifentanyl Total intravenous anesthesia (TIVA: propofol + remifentanyl)

The following parameters will be recorded:

Hemodynamic data: blood pressure, heart rate Oxygenation parameters: SpO₂, SpO₂/FiO₂ ratio Cerebral and depth monitoring: NIRS, BIS Respiratory mechanics Oxygen Saturation Index (OSI = \[Pmean × FiO₂\] / SpO₂) Mechanical ventilator parameters

Time Points for Measurement:

Before induction After induction After intubation Every 20 minutes intraoperatively After extubation

Additional Intraoperative Variables:

Duration of surgery and anesthesia

Total anesthetic drug consumption:

Desflurane and remifentanyl Propofol and remifentanyl (TIVA group) Intraoperative blood transfusion (yes/no) Total blood loss Urine output Recovery time Postoperative Follow-up ICU admission (planned or unplanned)

Pain assessment using Numeric Rating Scale (NRS):

PACU Postoperative 1st, 3rd, 6th, 12th, and 24th hours

Postoperative Complications:

Nausea and vomiting Hypotension Arrhythmia (bradycardia, tachycardia) Pulmonary edema Atelectasis Pneumonia Pneumothorax Pleural effusion Cognitive dysfunction

Other Outcomes:

Postoperative MoCA and Beck Anxiety Scale scores Length of hospital stay Length of ICU stay (if applicable) Mortality during follow-up