BIS in ICU Interventional Study

Effect of BIS-Guided Sedation on Clinical Outcomes in Postoperative Cardiac Surgery ICU Patients: A Prospective, Randomized Controlled Trial

This study will test whether using a Bispectral Index (BIS) monitor to guide sedation can reduce the amount of sedative medication given to adults in the intensive care unit (ICU) after cardiac surgery. BIS is a non-invasive, EEG-based monitor that shows a number from 0-100 to reflect level of consciousness. Researchers will compare BIS-guided sedation to standard sedation guided by clinical scales (such as the Richmond Agitation-Sedation Scale, RASS).

About 144 participants will be randomly assigned (1:1) to one of two groups at two hospitals in Austria (Medical University of Graz and Klinikum Wels-Grieskirchen). In the BIS group, clinicians will use BIS values and standard care to titrate sedation and will aim to avoid sustained BIS values below 50. In the control group, sedation will follow standard practices using clinical scales; BIS will be recorded but hidden from caregivers. The trial is open-label for treating staff; outcome assessors and data analysts will be blinded.

Participants will be in the study during their ICU sedation and mechanical ventilation period (typically more than 6 hours), with follow-up through ICU and hospital discharge. The primary outcome is the time-averaged dose of propofol (mg/kg/h) given during continuous ICU sedation until weaning (up to 72 hours). Secondary outcomes include duration of ventilation and sedation, depth of sedation measures, sedative and catecholamine doses, pulmonary infections (including ventilator-associated pneumonia), ICU and hospital length of stay, delirium, and in-hospital mortality.

Risks are minimal and may include mild skin irritation from forehead electrodes. Possible benefits include improved sedation management; benefits are not guaranteed. Taking part is voluntary.

Study Overview

• Status: Not yet recruiting
• Conditions: Critical Illness; Pneumonia, Ventilator-Associated; Delirium - Postoperative; Postoperative Complications (Cardiopulmonary); Cardiac Surgical Procedures (Postoperative Population)
• Intervention / Treatment: Other: Device-guided sedation; Other: standard sedation practice

• Study Type: Interventional
• Enrollment (Estimated): 144
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Selina Sartori, MD; Phone Number: +43 664 1652783; Email: selina.sartori@medunigraz.at

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Age ≥ 18 years
• Undergoing cardiac surgery with subsequent admission to the intensive care unit (e.g., valve surgery, coronary artery bypass grafting, aortic surgery)
• Planned or expected duration of invasive mechanical ventilation > 6 hours postoperatively
• Requirement for continuous sedation during ICU stay

Exclusion Criteria:

• Pre-existing neurological disorders affecting consciousness or sedation assessment (e.g., severe dementia, epileptic encephalopathy).
• Acute neurological events in the perioperative period (e.g., stroke, intracranial hemorrhage).
• Severe hepatic dysfunction (Child-Pugh Class C).
• Participation in another interventional study potentially affecting sedation or cognitive outcomes.
• Pregnancy or lactation.
• Do-not-intubate (DNI)/Do-not-resuscitate (DNR) orders or documented limitation of therapy.
• Patients in whom short-term survival is deemed unlikely due to the clinical course.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Supportive Care
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Single

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: BIS-Guided Sedation; Continuous BIS monitoring is visible to the care team. Sedation is titrated using BIS values plus routine clinical assessment, with instruction to avoid sustained BIS < 50.	Other: Device-guided sedation; in addition to standard clinical sedation management, BIS monitoring will be applied in order to avoid unintended deep sedation
Active Comparator: Standard Sedation with Blinded BIS; Sedation is managed per standard clinical practice using validated clinical scales (e.g., RASS). BIS monitoring is performed but hidden from caregivers (not used for clinical decisions).	Other: standard sedation practice; sedation due to standard clinical practice, using sedation scores such as RASS-Score

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
time-averaged Propofol dose during continuous ICU sedation	mean Propofol infusion rate in mg/kg/h averaged over the continuous sedation period until discontinuation of Propofol (or switch to other sedative, return to OR or death)	immediately after discontinuation of propofol

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Duration of invasive mechanical ventilation	Duration of invasive mechanical ventilation in hours	immediately after extubation
Duration of continuous sedation	Duration of continuous sedation in hours	immediately after extubation
Incidence of pulmonary infections	pneumonie, tracheobronchial infections	at ICU discharge
Proportion of time spent in deep sedation	Proportion of time during sedation with BIS values <50	immediately after discontinuation of Propofol
BIS values over time	Bispectral Index (BIS) is a monitoring system providing values from 0 to 100, reflecting brain activity with 100 being fully awake an 0 indicating no brain activity (isoelectric EEG). A range of 40-60 typicallysignifies adequate general anesthesia during surgery.	immediately after discontinuation of Propofol
Length of ICU stay	Length of ICU stay in days	at ICU discharge
Total hospital length of stay	Total hospital length of stay in days	at hospital discharge
In-hospital mortality		at ICU discharge
Incidence of ICU delirium	Incidence of ICU delirium (assessed using CAM-ICU or ICDSC)	immediately after extubation
Time-averaged catecholamine dose administered (in mcg/kg/min) during continuous sedation		immediately after discontinuation of Propofol

Collaborators and Investigators

• Sponsor: Medical University of Graz

Study record dates

Study Major Dates

• Study Start (Estimated): July 1, 2026
• Primary Completion (Estimated): May 1, 2027
• Study Completion (Estimated): June 1, 2027

Study Registration Dates

• First Submitted: December 4, 2025
• First Submitted That Met QC Criteria: January 13, 2026
• First Posted (Actual): January 20, 2026

Study Record Updates

• Last Update Posted (Actual): May 29, 2026
• Last Update Submitted That Met QC Criteria: May 28, 2026
• Last Verified: January 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Healthcare-Associated Pneumonia; Neurologic Manifestations; Nervous System Diseases; Mental Disorders; Pathologic Processes; Disease Attributes; Respiratory Tract Infections; Infections; Respiratory Tract Diseases; Confusion; Neurobehavioral Manifestations; Neurocognitive Disorders; Lung Diseases; Pneumonia; Cross Infection; Iatrogenic Disease; Delirium; Pathological Conditions, Signs and Symptoms; Signs and Symptoms; Emergence Delirium; Critical Illness; Pneumonia, Ventilator-Associated; Postoperative Complications
• Other Study ID Numbers: 1579

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES

IPD Plan Description

Types of data: De-identified individual participant data (IPD) underlying the primary and secondary outcomes (e.g., demographics, baseline characteristics, BIS values, sedation dosing, ventilation duration, ICU/hospital length of stay, delirium measures, adverse events).

Supporting documents: Study protocol, statistical analysis plan (SAP), data dictionary/metadata, and analytic code.

• IPD Sharing Time Frame: starting 12 months after publication of the primary results and for a period of 5 years thereafter

IPD Sharing Access Criteria

Available to qualified researchers with a methodologically sound proposal. Requests will be reviewed by the Principal investigator. Approved requestors must:

Sign a data use agreement (DUA) prohibiting re-identification and onward sharing.

Obtain local IRB/ethics approval (or exemption) for the proposed analysis. Use data solely for the approved purpose and comply with GDPR and applicable data protection laws.

Mode of access: Controlled access via the University Hospital Graz secure institutional repository. Instructions for requesting access will be provided via the study contact email: [selina.sartori@medunigraz.at]

• IPD Sharing Supporting Information Type: STUDY_PROTOCOL; SAP; ICF

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No