DSA vs. BIS for Anesthesia and Analgesia Management

Dr Abdurrahman Yurtaslan Ankara Oncology Training and Research Hospital45 enrolled

Overview

The purpose of this study is to compare two different methods of monitoring brain activity (anesthesia depth) during gynecological surgeries. When patients undergo surgery under general anesthesia, doctors use monitors to ensure they are at the right level of sleep and pain relief. Traditionally, a method called the Bispectral Index (BIS) is used, which provides a single number to represent brain activity. A newer method, called Density Spectral Array (DSA), provides a more detailed, color-coded map of brain waves in real-time. Researchers want to see if using the more detailed DSA map helps anesthesiologists adjust medication more precisely. The study will compare the total amount of anesthetic and pain-relief drugs used in patients monitored with DSA versus those monitored with BIS. The goal is to determine if DSA leads to more personalized care, potentially reducing drug use and improving recovery after surgery

This prospective observational study will include 45 patients undergoing elective gynecological oncology surgery under general anesthesia. Patients will be monitored using standard anesthesia monitoring (Pulse oximetry, non-invasive blood pressure, ECG, and ETCO2) along with brain activity monitoring. The anesthesia management will follow a Total Intravenous Anesthesia (TIVA) protocol consisting of propofol, remifentanil, and lidocaine. Patients will be divided into two groups based on the anesthesiologist's preference for monitoring anesthesia depth: the Bispectral Index (BIS) group and the Density Spectral Array (DSA) group. Hemodynamic parameters (heart rate, blood pressure), BIS values, and DSA images will be recorded at specific intervals: before induction, after induction, at the start of surgery, every 30 minutes during the procedure, at the end of surgery, and after extubation. The total amounts of propofol and remifentanil used during the operation will be documented for each patient. In the postoperative period, patients will be monitored in the recovery unit at the 15th, 30th, and 60th minutes. Visual Analog Scale (VAS) scores for pain, additional analgesic requirements, and hemodynamic parameters will be recorded. Once orientation and cooperation are established, patients will also be evaluated for any signs of intraoperative awareness

Study Type

OBSERVATIONAL

Enrollment

Interventions

Density Spectral Array (DSA) MonitoringDEVICE

Anesthesia depth and analgesia will be managed using real-time color-coded EEG power spectrum analysis (Density Spectral Array). The anesthesiologist will adjust the infusion rates of propofol and remifentanil based on the visual representation of brain wave frequencies and power distribution. This method allows for a more detailed and individualized assessment of the patient's response to anesthetic and analgesic agents compared to numerical indices alone.

Bispectral Index (BIS) MonitoringDEVICE

Anesthesia depth will be managed using the processed EEG numerical index (Bispectral Index). The anesthesiologist will adjust the infusion rates of propofol and remifentanil to maintain a target BIS value between 40 and 60. This represents the standard clinical practice for monitoring the hypnotic component of general anesthesia using a simplified numerical scale from 0 to 100.

Eligibility

Sex: FEMALEMin age: 18 YearsMax age: 65 Years

Medical Language ↔ Plain English

Inclusion Criteria: * Aged between 18 and 65 years * ASA physical status I-III * Patients scheduled for elective gynecological oncology surgery * Body mass index (BMI) ≤ 35 kg/m² * Able to provide voluntary informed consent * Patients who do not require premedication Exclusion Criteria: * Allergy or hypersensitivity to propofol, opioids, or lidocaine * Liver failure or kidney failure * Previous adjuvant chemotherapy * Emergency surgery * Operations lasting longer than 3 hours * Neurological diseases such as epilepsy, Alzheimer's disease, or dementia * Cerebrovascular disease or known brain lesions * Heart conduction disorders such as high-degree atrioventricular block * Patients requiring premedication * History of chronic pain * Chronic opioid use * Diabetes mellitus with neuropathy * Patients unable to establish cooperation

Outcomes

Primary Outcomes

Total Amount of Propofol Consumption

The total amount of propofol (in milligrams) administered to the patient during the entire surgical procedure to maintain the target anesthesia depth. The study compares whether monitoring with Density Spectral Array (DSA) leads to a significant reduction in total propofol consumption compared to Bispectral Index (BIS) monitoring.

Time frame: From the start of anesthesia induction until the end of the surgical procedure (approximately 1 to 3 hours).

Secondary Outcomes

Total Amount of Remifentanil Consumption

The total amount of remifentanil (in micrograms) administered to the patient during the entire surgical procedure to maintain the target analgesia level. The study compares whether monitoring with Density Spectral Array (DSA) leads to a significant reduction in total remifentanil consumption compared to Bispectral Index (BIS) monitoring.

Time frame: From the start of anesthesia induction until the end of the surgical procedure (approximately 1 to 3 hours).

Postoperative Pain Scores (Visual Analog Scale - VAS)

Assessment of postoperative pain using the Visual Analog Scale (VAS), where 0 represents no pain and 10 represents the worst possible pain. The scores will be recorded to evaluate the quality of postoperative analgesia between the two groups.

Time frame: At the 15th, 30th, and 60th minutes in the post-anesthesia care unit (PACU).

Postoperative Rescue Analgesic Requirement

The total amount and frequency of additional (rescue) analgesic medications required by the patient in the recovery unit. This measure evaluates whether the intraoperative anesthesia management with Density Spectral Array (DSA) reduces the need for extra pain relief compared to Bispectral Index (BIS) monitoring.

Time frame: During the first 60 minutes in the post-anesthesia care unit (PACU).