Validation of the PRST Score Against Bispectral Index

NCT07590388 | Completed

• 1 other identifier: PRST-BIS-RCT-2026
• Study Type: interventional
• Target: 183
• Locations: 1 country
• Sites: 1

Brief 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. 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:

1. 1.Does the PRST score correlate with BIS values during general anesthesia?
2. 2.Does visible BIS-guided monitoring improve anesthetic depth assessment compared with PRST-guided monitoring alone?
3. 3.Undergo elective surgery under general anesthesia
4. 4.Receive intraoperative anesthetic depth monitoring using PRST score alone or PRST combined with BIS monitoring
5. 5.Have PRST score, BIS, heart rate, and blood pressure recorded at predefined intraoperative timepoints
6. 6.Complete a postoperative interview assessing recall, dreaming, and anesthesia-related discomfort

Conditions

Elective Surgeries; General Anesthesia; BIS

Keywords

general anesthesia; bispectral index; PRST score; Depth of Anesthesia

Outcome Measures

Primary Outcomes (2)

• 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.

  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.

  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

  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

  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

  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

  T3 (before skin incision), T4 (5 minutes after incision), and T5-T6 (15 and 30 minutes during the maintenance phase).

• Postoperative discomfort

  Immediately after recovery from general anesthesia

Study Arms (2)

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.

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.

Device: PRST + BIS Monitoring

Interventions

PRST Monitoring DEVICE

Clinical anesthetic depth monitoring using PRST score assessment without visible BIS-guided titration.

Control (PRST group)

PRST + BIS Monitoring DEVICE

Clinical anesthetic depth monitoring using PRST score combined with visible BIS-guided anesthetic titration targeting BIS 40-60.

Intervention (PRST + BIS group)

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Scheduled for elective surgery under general anesthesia

You may not qualify if:

• 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

Sponsors & Collaborators

• Gadjah Mada University: lead

Study Sites (1)

RSUP Dr. Sardjito

Yogyakarta, Special Region of Yogyakarta, 55281, Indonesia

Location

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: DOUBLE
• Who Masked: PARTICIPANT, OUTCOMES ASSESSOR
• Purpose: DIAGNOSTIC
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Consultant Anesthesiologist and Principal Investigator

Study Record Dates

• First Submitted: May 11, 2026
• First Posted: May 15, 2026
• Study Start: October 26, 2025
• Primary Completion: January 5, 2026
• Study Completion: January 5, 2026
• Last Updated: May 15, 2026

Record last verified: 2026-05

Locations

ID (1)