Elective SurgeriesNCT07590388
Validation of the PRST Score Against Bispectral Index
A study testing PRST Monitoring and PRST + BIS Monitoring in people with Elective Surgeries and General Anesthesia, run by Gadjah Mada University at 1 site in Indonesia.
Trial summary
The goal of this randomized controlled trial is to evaluate whether the PRST (Evans) score is a valid method for monitoring the depth of general anesthesia in adult surgical patients. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Elective Surgeries, General Anesthesia, BIS
- What is being tested?
- PRST Monitoring and PRST + BIS Monitoring
- Type of treatment
- Medical device
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 183 participants
- Where
- 1 siteIndonesia
- Study dates
- 26 Oct 2025to 5 Jan 2026
- Phase
- Interventional
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Scheduled for elective surgery under general anesthesia
Who cannot join
- Unstable hemodynamic conditions
- Contraindications to specific anesthetic agents or significant neurological disorders (e.g., Parkinson's disease, stroke, or dementia)
- Receiving medications known to influence EEG activity, such as anticonvulsants
- Unable to provide informed consent
Trial locations and contacts
1 site in 1 country.
Indonesia1 site
RSUP Dr. Sardjito
Yogyakarta, Special Region of Yogyakarta, 55281
About this study
Official title: Validation of the PRST Score Against Bispectral Index During General Anesthesia: A Randomized Controlled Trial
The goal of this randomized controlled trial is to evaluate whether the PRST (Evans) score is a valid method for monitoring the depth of general anesthesia in adult surgical patients. It will also assess whether combining the PRST score with Bispectral Index (BIS) monitoring improves anesthetic depth assessment compared with PRST-guided monitoring alone.
The main questions it aims to answer are:
Read more
- Does the PRST score correlate with BIS values during general anesthesia?
- Does visible BIS-guided monitoring improve anesthetic depth assessment compared with PRST-guided monitoring alone?
Researchers will compare patients managed using PRST-guided monitoring alone with patients managed using PRST plus visible BIS-guided monitoring.
Participants will:
- Undergo elective surgery under general anesthesia
- Receive intraoperative anesthetic depth monitoring using PRST score alone or PRST combined with BIS monitoring
- Have PRST score, BIS, heart rate, and blood pressure recorded at predefined intraoperative timepoints
- Complete a postoperative interview assessing recall, dreaming, and anesthesia-related discomfort
Read the detailed description
This single-center, parallel-group randomized controlled trial (RCT) aims to evaluate the validity of the PRST (Evans) score for monitoring the depth of general anesthesia and to assess its relationship with Bispectral Index (BIS) monitoring in adult surgical patients undergoing elective procedures under general anesthesia.
Intraoperative awareness remains a clinically important complication during general anesthesia. Traditional clinical assessment methods such as the PRST score evaluate autonomic responses including systolic blood pressure, heart rate, sweating, and lacrimation, whereas BIS provides an electroencephalography-based objective assessment of hypnotic depth. This study investigates whether combining PRST assessment with BIS monitoring may improve anesthetic depth evaluation compared with PRST-guided monitoring alone.
Eligible participants are randomized into either a PRST-guided monitoring group or a PRST plus visible BIS-guided monitoring group. Standard anesthetic induction and maintenance protocols are applied in both groups. In the intervention group, BIS monitoring is used as an adjunctive tool to guide anesthetic depth management, with a target BIS range of 40-60.
PRST score, BIS values, heart rate (HR), and mean arterial pressure (MAP) are recorded at predefined intraoperative timepoints including T0 (baseline before induction), T1 (after induction before laryngoscopy), T2 (1-3 minutes after airway instrumentation), T3 (before skin incision), T4 (5 minutes after incision), and T5-T6 (15 and 30 minutes during the maintenance phase). Postoperative interviews are conducted to evaluate recall, dreaming, and anesthesia-related discomfort.
The primary objective is to determine the association between PRST score and BIS values during general anesthesia. Secondary objectives include evaluation of hemodynamic responses, anesthetic delivery variables, postoperative recall-related events, and the diagnostic performance of PRST score in identifying BIS-defined light anesthesia.
- Conditions
- Elective Surgeries, General Anesthesia, BIS
- Being tested
- PRST Monitoring, PRST + BIS Monitoring
- Keywords
- general anesthesia, bispectral index, PRST score, Depth of Anesthesia
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
PRST MonitoringDevice
Clinical anesthetic depth monitoring using PRST score assessment without visible BIS-guided titration.
PRST + BIS MonitoringDevice
Clinical anesthetic depth monitoring using PRST score combined with visible BIS-guided anesthetic titration targeting BIS 40-60.
| Study group | Role | What they receive |
|---|---|---|
| Control (PRST group) | Active comparator | Participants in this group will undergo elective surgery under general anesthesia with anesthetic depth managed using standard clinical monitoring and PRST-guided assessment. PRST components, including systolic blood pressure response, heart rate response, sweating, and lacrimation, will be assessed at predefined intraoperative timepoints. Receives: Device: PRST Monitoring |
| Intervention (PRST + BIS group) | Experimental | Participants in this group will undergo elective surgery under general anesthesia with anesthetic depth managed using standard clinical monitoring, PRST-guided assessment, and visible BIS monitoring. BIS monitoring will be initiated after induction and used as an adjunct to guide hypnotic depth titration, with a typical target BIS range of 40-60. PRST score, BIS values, and hemodynamic parameters will be recorded at predefined intraoperative timepoints. Receives: Device: PRST + BIS Monitoring |
What is being measured
The primary outcome is the main question the study is designed to answer.
PRST score
PRST components were assessed as follows: SBP response (increase from baseline <15 mmHg = 0; 15-30 mmHg = 1; >30 mmHg = 2), HR response (increase from baseline <15 bpm = 0; 15-30 bpm = 1; >30 bpm = 2), sweating (absent = 0; present = 1), and lacrimation (absent = 0; present = 1). The total PRST score ranged from 0 to 6 with higher scores indicating greater autonomic response to nociceptive stimuli.
Measured: T0 (baseline before induction), T1 (after induction before laryngoscopy), T2 (1-3 minutes after airway instrumentation), T3 (before skin incision), T4 (5 minutes after incision), and T5-T6 (15 and 30 minutes during the maintenance phase).
BIS Score
Bispectral Index (BIS) monitoring is an electroencephalography-based anesthetic depth monitoring system used to assess the hypnotic state during general anesthesia. In this study, BIS monitoring is initiated after anesthetic induction and used as an adjunctive tool to guide anesthetic depth management, with a target BIS range of 40-60 during maintenance of general anesthesia. Continuous BIS values are recorded throughout the intraoperative period to evaluate anesthetic depth and correlation with PRST score measurements.
Measured: T0 (baseline before induction), T1 (after induction before laryngoscopy), T2 (1-3 minutes after airway instrumentation), T3 (before skin incision), T4 (5 minutes after incision), and T5-T6 (15 and 30 minutes during the maintenance phase).
Secondary outcomes (6)
Heart Rate
Measured: T0 (baseline before induction), T1 (after induction before laryngoscopy), T2 (1-3 minutes after airway instrumentation), T3 (before skin incision), T4 (5 minutes after incision), and T5-T6 (15 and 30 minutes during the maintenance phase).
Mean Arterial Pressure
Measured: T0 (baseline before induction), T1 (after induction before laryngoscopy), T2 (1-3 minutes after airway instrumentation), T3 (before skin incision), T4 (5 minutes after incision), and T5-T6 (15 and 30 minutes during the maintenance phase).
Sevoflurane dial setting
Sevoflurane dial setting refers to the vaporizer concentration setting used to deliver inhaled sevoflurane during maintenance of general anesthesia. In this study, sevoflurane concentration is adjusted intraoperatively according to anesthetic depth assessment and clinical monitoring parameters, including PRST score and BIS monitoring when applicable.
Measured: T3 (before skin incision), T4 (5 minutes after incision), and T5-T6 (15 and 30 minutes during the maintenance phase).
End-tidal minimum alveolar concentration (MAC) values
End-tidal minimum alveolar concentration (MAC) values represent the measured concentration of inhaled anesthetic agent in exhaled gas and are used as an indicator of anesthetic potency during general anesthesia. In this study, end-tidal MAC values are continuously monitored intraoperatively and recorded at predefined timepoints to evaluate anesthetic delivery and depth of anesthesia in relation to PRST score and BIS monitoring.
Measured: T3 (before skin incision), T4 (5 minutes after incision), and T5-T6 (15 and 30 minutes during the maintenance phase).
Postoperative discomfort
Postoperative discomfort refers to patient-reported unpleasant physical or psychological experiences following general anesthesia and surgery. Assessment is performed postoperatively using structured interview questions evaluating discomfort related to anesthesia, intraoperative experience, or recovery period. Responses are recorded and compared between study groups.
Measured: Immediately after recovery from general anesthesia
Dreaming
Dreaming refers to patient-reported dream experiences occurring during the peri-anesthetic period under general anesthesia. Assessment is performed postoperatively using structured interview questions adapted from the modified Brice interview to identify the presence or absence of dreaming during anesthesia and recovery. Responses are recorded and compared between study groups.
Measured: Immediately after recovery from general anesthesia
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted15 May 2026
- Study start26 Oct 2025
- Primary completion5 Jan 2026
- Study completion5 Jan 2026
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Elective SurgeriesStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Diagnosis
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Double blind
- Who is masked
- Participant, Outcomes assessor
- Enrolment
- 183 participants (actual)
Sponsor and investigators
- Lead sponsor
- Gadjah Mada University
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Dady Sudadi, Gadjah Mada University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07590388
- Sponsor's protocol ID
- PRST-BIS-RCT-2026
- Status last verified
- May 2026
- First submitted
- 11 May 2026
- Last updated
- 15 May 2026
- Results posted
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Undecided
Study at a glance
From the registry record, last updated by the sponsor on 15 May 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Validation of the PRST Score Against Bispectral Index During General Anesthesia: A Randomized Controlled Trial
- ClinicalTrials.gov ID
- NCT07590388
- Acronym / sponsor ID
- PRST-BIS-RCT-2026
- Conditions
- Elective Surgeries, General Anesthesia, BIS
- Keywords
- general anesthesia, bispectral index, PRST score, Depth of Anesthesia
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 183 participants (actual)
- Lead sponsor
- Gadjah Mada UniversityUniversity, hospital or other
- Study start
- 26 Oct 2025 (actual)
- Primary completion
- 5 Jan 2026 (actual)
- Study completion
- 5 Jan 2026 (actual)
- First posted
- 15 May 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The goal of this randomized controlled trial is to evaluate whether the PRST (Evans) score is a valid method for monitoring the depth of general anesthesia in adult surgical patients. It will also assess whether combining the PRST score with Bispectral Index (BIS) monitoring improves anesthetic depth assessment compared with PRST-guided monitoring alone.
The main questions it aims to answer are:
- Does the PRST score correlate with BIS values during general anesthesia?
- Does visible BIS-guided monitoring improve anesthetic depth assessment compared with PRST-guided monitoring alone?
Researchers will compare patients managed using PRST-guided monitoring alone with patients managed using PRST plus visible BIS-guided monitoring.
Participants will:
- Undergo elective surgery under general anesthesia
- Receive intraoperative anesthetic depth monitoring using PRST score alone or PRST combined with BIS monitoring
- Have PRST score, BIS, heart rate, and blood pressure recorded at predefined intraoperative timepoints
- Complete a postoperative interview assessing recall, dreaming, and anesthesia-related discomfort
Detailed description
This single-center, parallel-group randomized controlled trial (RCT) aims to evaluate the validity of the PRST (Evans) score for monitoring the depth of general anesthesia and to assess its relationship with Bispectral Index (BIS) monitoring in adult surgical patients undergoing elective procedures under general anesthesia.
Intraoperative awareness remains a clinically important complication during general anesthesia. Traditional clinical assessment methods such as the PRST score evaluate autonomic responses including systolic blood pressure, heart rate, sweating, and lacrimation, whereas BIS provides an electroencephalography-based objective assessment of hypnotic depth. This study investigates whether combining PRST assessment with BIS monitoring may improve anesthetic depth evaluation compared with PRST-guided monitoring alone.
Eligible participants are randomized into either a PRST-guided monitoring group or a PRST plus visible BIS-guided monitoring group. Standard anesthetic induction and maintenance protocols are applied in both groups. In the intervention group, BIS monitoring is used as an adjunctive tool to guide anesthetic depth management, with a target BIS range of 40-60.
PRST score, BIS values, heart rate (HR), and mean arterial pressure (MAP) are recorded at predefined intraoperative timepoints including T0 (baseline before induction), T1 (after induction before laryngoscopy), T2 (1-3 minutes after airway instrumentation), T3 (before skin incision), T4 (5 minutes after incision), and T5-T6 (15 and 30 minutes during the maintenance phase). Postoperative interviews are conducted to evaluate recall, dreaming, and anesthesia-related discomfort.
The primary objective is to determine the association between PRST score and BIS values during general anesthesia. Secondary objectives include evaluation of hemodynamic responses, anesthetic delivery variables, postoperative recall-related events, and the diagnostic performance of PRST score in identifying BIS-defined light anesthesia.
Study design
- Primary purpose
- Diagnosis
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Double blind (participant, outcomes assessor)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Control (PRST group) | Active comparator | Device: PRST MonitoringParticipants in this group will undergo elective surgery under general anesthesia with anesthetic depth managed using standard clinical monitoring and PRST-guided assessment. PRST components, including systolic blood pressure response, heart rate response, sweating, and lacrimation, will be assessed at predefined intraoperative timepoints. |
| Intervention (PRST + BIS group) | Experimental | Device: PRST + BIS MonitoringParticipants in this group will undergo elective surgery under general anesthesia with anesthetic depth managed using standard clinical monitoring, PRST-guided assessment, and visible BIS monitoring. BIS monitoring will be initiated after induction and used as an adjunct to guide hypnotic depth titration, with a typical target BIS range of 40-60. PRST score, BIS values, and hemodynamic parameters will be recorded at predefined intraoperative timepoints. |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (1 listed)
- Scheduled for elective surgery under general anesthesia
Key exclusion criteria (4 listed)
- Unstable hemodynamic conditions
- Contraindications to specific anesthetic agents or significant neurological disorders (e.g., Parkinson's disease, stroke, or dementia)
- Receiving medications known to influence EEG activity, such as anticonvulsants
- Unable to provide informed consent
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| PRST MonitoringClinical anesthetic depth monitoring using PRST score assessment without visible BIS-guided titration. | Device | Control (PRST group) |
| PRST + BIS MonitoringClinical anesthetic depth monitoring using PRST score combined with visible BIS-guided anesthetic titration targeting BIS 40-60. | Device | Intervention (PRST + BIS group) |
Primary outcome
PRST score
Time frame: T0 (baseline before induction), T1 (after induction before laryngoscopy), T2 (1-3 minutes after airway instrumentation), T3 (before skin incision), T4 (5 minutes after incision), and T5-T6 (15 and 30 minutes during the maintenance phase).
PRST components were assessed as follows: SBP response (increase from baseline <15 mmHg = 0; 15-30 mmHg = 1; >30 mmHg = 2), HR response (increase from baseline <15 bpm = 0; 15-30 bpm = 1; >30 bpm = 2), sweating (absent = 0; present = 1), and lacrimation (absent = 0; present = 1). The total PRST score ranged from 0 to 6 with higher scores indicating greater autonomic response to nociceptive stimuli.
BIS Score
Time frame: T0 (baseline before induction), T1 (after induction before laryngoscopy), T2 (1-3 minutes after airway instrumentation), T3 (before skin incision), T4 (5 minutes after incision), and T5-T6 (15 and 30 minutes during the maintenance phase).
Bispectral Index (BIS) monitoring is an electroencephalography-based anesthetic depth monitoring system used to assess the hypnotic state during general anesthesia. In this study, BIS monitoring is initiated after anesthetic induction and used as an adjunctive tool to guide anesthetic depth management, with a target BIS range of 40-60 during maintenance of general anesthesia. Continuous BIS values are recorded throughout the intraoperative period to evaluate anesthetic depth and correlation with PRST score measurements.
6 secondary outcomes
Heart Rate
Time frame: T0 (baseline before induction), T1 (after induction before laryngoscopy), T2 (1-3 minutes after airway instrumentation), T3 (before skin incision), T4 (5 minutes after incision), and T5-T6 (15 and 30 minutes during the maintenance phase).
Mean Arterial Pressure
Time frame: T0 (baseline before induction), T1 (after induction before laryngoscopy), T2 (1-3 minutes after airway instrumentation), T3 (before skin incision), T4 (5 minutes after incision), and T5-T6 (15 and 30 minutes during the maintenance phase).
Sevoflurane dial setting
Time frame: T3 (before skin incision), T4 (5 minutes after incision), and T5-T6 (15 and 30 minutes during the maintenance phase).
End-tidal minimum alveolar concentration (MAC) values
Time frame: T3 (before skin incision), T4 (5 minutes after incision), and T5-T6 (15 and 30 minutes during the maintenance phase).
Postoperative discomfort
Time frame: Immediately after recovery from general anesthesia
Dreaming
Time frame: Immediately after recovery from general anesthesia
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 15 May 2026.
- Individual participant dataSharing planned: Undecided
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing PRST Monitoring and PRST + BIS Monitoring in people with Elective Surgeries and General Anesthesia, run by Gadjah Mada University at 1 site in Indonesia.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 1 inclusion and 4 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 15 May 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Indonesia. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
PRST score (time frame: T0 (baseline before induction), T1 (after induction before laryngoscopy), T2 (1-3 minutes after airway instrumentation), T3 (before skin incision), T4 (5 minutes after incision), and T5-T6 (15 and 30 minutes during the maintenance phase).). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 15 May 2026.