An interventional study of Midazolam and Dexmedetomidine in Depth of Anesthesia Monitoring and BIS-EEG, sponsored by China-Japan Friendship Hospital. Recruiting at 2 sites in China. Open to participants aged 18 Years to 65 Years. Per ClinicalTrials.gov, last updated 2026-10-28.
Sponsored by China-Japan Friendship Hospital · Not applicable, Interventional, and Diagnostic
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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.
China-Japan Friendship Hospital is the lead sponsor of 179 studies on the registry; 112 are open to participants now.
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Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
The anaesthetists’ scale of health before surgery: I is healthy, II has a mild illness that is under control, III a severe one, IV a severe illness that is a constant threat to life. V and VI are used for the critically ill and for organ donors.
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
ASA physical status
The anaesthetists’ scale of health before surgery: I is healthy, II has a mild illness that is under control, III a severe one, IV a severe illness that is a constant threat to life. V and VI are used for the critically ill and for organ donors.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
BMI (body mass index)
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Participants receive standardized propofol-remifentanil total intravenous anesthesia without administration of the study adjunct anesthetic drug.
Drug: Propofol · Drug: Remifentanil
Participants receive standardized propofol-remifentanil total intravenous anesthesia plus midazolam according to the study protocol.
Drug: Midazolam · Drug: Propofol · Drug: Remifentanil
Participants receive standardized propofol-remifentanil total intravenous anesthesia plus dexmedetomidine according to the study protocol.
Drug: Dexmedetomidine · Drug: Propofol · Drug: Remifentanil
Participants receive standardized propofol-remifentanil total intravenous anesthesia plus esketamine according to the study protocol.
Drug: Esketamine · Drug: Propofol · Drug: Remifentanil
Midazolam administered as an adjunct to standardized propofol-remifentanil total intravenous anesthesia according to the study protocol.
Dexmedetomidine administered as an adjunct to standardized propofol-remifentanil total intravenous anesthesia according to the study protocol.
Esketamine administered as an adjunct to standardized propofol-remifentanil total intravenous anesthesia according to the study protocol.
Propofol will be administered as part of standardized total intravenous anesthesia in all study groups.
Remifentanil will be administered as part of standardized total intravenous anesthesia in all study groups.
Change in Bispectral Index (BIS) value from the pre-intervention baseline
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.
Time frame: Baseline and 5, 10, 15, 20, 25, 30 minutes after adjunct drug administration
Change in mean arterial pressure from pre-intervention baseline
Change in mean arterial pressure (MAP) 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.
Time frame: Baseline and 5, 10, 15, 20, 25, and 30 minutes after adjunct drug administration.
Change in heart rate from pre-intervention baseline
Change in heart rate (HR) from the stable pre-intervention baseline will be compared among the four study groups after administration of the assigned adjunct anesthetic drug.
Time frame: Baseline and 5, 10, 15, 20, 25, and 30 minutes after adjunct drug administration.
Time from discontinuation of anesthetic drugs to airway device removal
The time interval from discontinuation of anesthetic drugs to removal of the airway device will be recorded.
Time frame: From discontinuation of anesthetic drugs to airway device removal, up to 60 minutes.
Time to Aldrete score of 10 in the post-anesthesia care unit
The time from admission to the post-anesthesia care unit to achievement of an Aldrete score of 10 will be recorded. The Aldrete score ranges from 0 to 10, with higher scores indicating better post-anesthesia recovery.
Time frame: From admission to the post-anesthesia care unit to achievement of an Aldrete score of 10, up to 2 hours.
Brice questionnaire assessment
The Brice questionnaire will be used to assess postoperative recall and awareness-related events.
Time frame: Before discharge from the post-anesthesia care unit, and at 24 and 48 hours after surgery.
Postoperative pain score
Postoperative pain intensity will be assessed using the numeric rating scale (NRS).
Time frame: At admission to the post-anesthesia care unit, before discharge from the post-anesthesia care unit, and at 24 and 48 hours after surgery.
Postoperative analgesic medication use
Use of postoperative analgesic medications, including opioid and non-opioid analgesics (e.g., NSAIDs), in the post-anesthesia care unit and hospital ward will be recorded and compared among study groups.
Time frame: From admission to the post-anesthesia care unit to 48 hours after surgery.
Change in pre-specified electroencephalographic spectral features from baseline
Pre-specified electroencephalographic spectral features, including alpha-to-delta power ratio, frontal alpha power, alpha peak frequency, and burst suppression ratio, will be evaluated and compared among study groups at baseline and after administration of the assigned adjunct anesthetic drug.
Time frame: Baseline and 5, 10, 15, 20, 25, and 30 minutes after adjunct drug administration.
Change in electroencephalographic relative spectral power from baseline
Relative power spectral density of delta, theta, alpha, beta, and gamma frequency bands will be compared among study groups at baseline and after administration of the assigned adjunct anesthetic drug.
Time frame: Baseline and 5, 10, 15, 20, 25, and 30 minutes after adjunct drug administration.
Plan to share: No
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Started Jul 2026 (actual). Primary completion is estimated for Jun 2027, 11 months after the start.
Start moved once since we started tracking on Sep 25, 2026: Jun 2026 → Jul 2026, on Oct 28, 2026.
Earlier changes are on the record history on ClinicalTrials.gov ↗
How these figures are worked out, and which studies are left out of them.
From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
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Studies of the drugs tested here: Midazolam · Dexmedetomidine · Esketamine
China-Japan Friendship Hospital →