The Effects of Midazolam, Dexmedetomidine, and Esketamine on Bispectral Index and Raw Electroencephalogram in Patients Under Propofol-Remifentanil Baseline Anesthesia

Condition(s) studied

Investigational drug(s) / intervention(s)

Midazolam: Midazolam administered as an adjunct to standardized propofol-remifentanil total intravenous anesthesia according to the study protocol.

Dexmedetomidine: Dexmedetomidine administered as an adjunct to standardized propofol-remifentanil total intravenous anesthesia according to the study protocol.

Esketamine: Esketamine administered as an adjunct to standardized propofol-remifentanil total intravenous anesthesia according to the study protocol.

Propofol: Propofol will be administered as part of standardized total intravenous anesthesia in all study groups.

Remifentanil: Remifentanil will be administered as part of standardized total intravenous anesthesia in all study groups.

Study summary

This prospective, single-center, randomized interventional study aims to investigate the effects of commonly used adjunct anesthetic drugs on the Bispectral Index (BIS) and electroencephalographic (EEG) activity during total intravenous anesthesia.

BIS monitoring is widely used to estimate the depth of anesthesia. However, previous studies suggest that certain anesthetic drugs, particularly dexmedetomidine and esketamine, may alter BIS values independently of the patient's actual level of consciousness. As a result, BIS readings may not always accurately reflect anesthetic depth when multiple drugs are administered together.

Adult patients undergoing elective laparoscopic cholecystectomy under standardized propofol-remifentanil anesthesia will be randomly assigned to receive one of the following adjunct drugs: midazolam, dexmedetomidine, esketamine, or no additional study drug (control group). Continuous BIS values and raw EEG signals will be recorded throughout the study period.

The primary objective is to compare changes in BIS values among different adjunct anesthetic drugs under otherwise similar anesthetic conditions. The study will also explore corresponding EEG characteristics associated with these changes. The findings are expected to improve understanding of drug-related differences in processed EEG monitoring and provide data for future development of more accurate anesthesia depth assessment methods.

Eligibility

Primary outcome measure(s)

• Change in Bispectral Index (BIS) value from the pre-intervention baseline — Baseline and 5, 10, 15, 20, 25, 30 minutes after adjunct drug administration
  Change in Bispectral Index value from the stable pre-intervention baseline will be compared among the four study groups after administration of the assigned adjunct anesthetic drug under standardized propofol-remifentanil total intravenous anesthesia. The pre-intervention baseline is defined as the stable BIS value immediately before administration of the assigned adjunct anesthetic drug. The Bispectral Index is a dimensionless electroencephalography-derived index ranging from 0 to 100, with lower values indicating deeper hypnotic states.

Trial sites (1)

More China-Japan Friendship Hospital trials in China