Major Abdominal Surgeries
Conditions
Keywords
Low-flow anesthesia., Desflurane, Major abdominal surgery, Bispectral Index (BIS)
Brief summary
This study investigates the effects of low-flow desflurane anesthesia in adult patients undergoing major abdominal surgery. The researchers will examine whether different low-flow strategies: Cause differences in the Bispectral Index (BIS), which measures brain activity during anesthesia, Affect postoperative cognitive functions such as memory and attention. Participants will: Receive desflurane anesthesia during surgery, Have anesthesia delivered at different low-flow rates, Have their BIS values monitored throughout the operation, Complete tests after surgery to evaluate their cognitive functions. This research will help determine the safety of different low-flow strategies and their impact on patients' cognitive recovery after surgery.
Detailed description
This prospective observational study is designed to evaluate the effects of different low-flow desflurane anesthesia strategies on intraoperative anesthetic depth, measured by the Bispectral Index (BIS), and on postoperative cognitive functions in patients undergoing major abdominal surgery. Patients will receive desflurane anesthesia delivered at different low-flow rates. Throughout surgery, BIS values will be continuously monitored to assess the depth of anesthesia. Postoperatively, standardized cognitive function tests will be performed at predetermined time points to evaluate potential cognitive impairment or recovery. The study aims to clarify whether the choice of low-flow strategy influences short-term postoperative neurocognitive outcomes. Quality assurance and data management procedures: Data collection will be conducted using standardized electronic case report forms (eCRFs). All collected data will undergo range and consistency checks against predefined rules. Source data verification will be performed through comparison with medical records and anesthetic monitoring logs. A data dictionary will be maintained, documenting each variable, coding standards (e.g., MedDRA where applicable), and reference ranges. Missing data will be handled according to a predefined plan, with cases flagged as missing, unusable, or inconsistent. Sample size and statistical plan: The sample size has been estimated to ensure sufficient statistical power to detect clinically meaningful differences in BIS and postoperative cognitive function scores between different low-flow strategies. Statistical analyses will include descriptive statistics, group comparisons using parametric or non-parametric tests, and regression models where appropriate. A detailed statistical analysis plan has been developed to address both primary and secondary endpoints. This study will provide evidence regarding the safety and neurocognitive impact of different low-flow desflurane strategies. Findings are expected to support clinical decision-making in optimizing anesthetic management for patients undergoing major abdominal procedures.
Interventions
Routine anesthesia care (desflurane at different low-flow rates: 0.5, 1.0, 1.5 L/min); no intervention assigned as part of the study.
Sponsors
Study design
Eligibility
Inclusion criteria
Patients aged 18-75 years ASA physical status I-III Scheduled for elective major abdominal surgery Provided written informed consent Normal preoperative neurocognitive function
Exclusion criteria
History of neurological or psychiatric disorders History of cognitive impairment Diagnosed hepatic or renal insufficiency Presence of other systemic diseases contraindicating anesthesia
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Change from Baseline in Mini-Mental State Examination (MMSE) Score Postoperatively | From baseline (preoperative assessment, within 24 hours before surgery) to postoperative assessments at 24 hours and 7 days after surgery | Measure: Change in cognitive function assessed by the Mini-Mental State Examination (MMSE) Time Frame: From baseline (preoperative assessment) to postoperative assessment (within 24 hours after surgery) Description: The MMSE will be used to evaluate changes in cognitive function in patients receiving desflurane anesthesia at different low-flow rates. The primary endpoint is the difference between preoperative and postoperative MMSE scores. |
Countries
Turkey (Türkiye)