Monitoring sedation depth with BIS after heart surgery

An Explorative Prospective Non-interventional Study on Sedation Depth in Postoperative Cardiac Surgery Patients Using Blinded BIS Monitoring

This study uses a BIS brain-monitor to try to see how deeply adult patients are sedated during the first 48 hours in the ICU after heart surgery while they are on a ventilator.

Quick facts

• Study type: Observational
• Enrollment: 50 (estimated)
• Ages: 18 Years and up
• Sex: All
• Sponsor: Medical University of Graz (Academic / other)
• Locations: 2 sites (Graz, Styria and 1 other locations)
• Trial ID: NCT07350109 on ClinicalTrials.gov

What this trial studies

This is a non-interventional, observational study that continuously records Bispectral Index (BIS) data in adults who require mechanical ventilation and continuous sedation after cardiac surgery. BIS readings are collected for the first 48 hours in the ICU but are blinded to the clinical team so patient care follows usual practice. The study aims to quantify how often deep sedation (BIS < 50) occurs and relate BIS patterns to outcomes such as duration of ventilation, ICU length of stay, infections, and delirium. Data are being collected at two hospital sites in Austria and include only patients with expected invasive ventilation longer than six hours postoperatively.

Who should consider this trial

Good fit: Adults (age ≥18) who have undergone cardiac surgery, are expected to need invasive mechanical ventilation for more than six hours postoperatively, and can provide consent or have a legal representative do so.

Not a fit: Patients with major pre-existing neurological disorders, acute perioperative neurological events, severe hepatic failure, pregnancy, very limited short-term survival, or those enrolled in conflicting interventional studies are unlikely to benefit from this observational monitoring.

Why it matters

Potential benefit: If successful, the findings could help clinicians recognize and reduce episodes of overly deep sedation, potentially shortening ventilation times and ICU stays.

How similar studies have performed: Previous work using BIS in ICU and post-operative settings exists but results have been mixed, with some reports of reduced over-sedation yet limited and inconsistent evidence for improvements in clinically important outcomes like delirium or ventilation duration.

Eligibility criteria

Inclusion Criteria:

* Age ≥ 18 years.
* Undergoing cardiac surgery with subsequent admission to the ICU
* expected duration of invasive mechanical ventilation \> 6 hours postop.
* Written informed consent obtained from the patient or legal representative (if the patient is not capable of consent).

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.
* Patients in whom short-term survival is deemed unlikely due to clinical course

Where this trial is running

Graz, Styria and 1 other locations

• Medical University Graz — Graz, Styria, Austria (Recruiting)
• Klinikum Wels — Wels, Upper Austria, Austria (Recruiting)

Study contacts

• Study coordinator: Selina Sartori, MD

Conditions Sedation After Cardiac Surgery