Investigation of Sedation Depth Via BIS Monitoring in ICU After Cardiac Surgery

Medical University of Graz50 enrolled

Overview

This study is a non-interventional, observational research project focused on monitoring sedation levels in patients who have undergone cardiac surgery. It uses a tool called Bispectral Index (BIS), which measures brain activity to assess sedation depth. The goal is to understand how often patients experience deep sedation (BIS \<50) during the first 48 hours in the ICU and to explore its impact on clinical outcomes like ventilation duration, ICU stay length, and complications such as infections or delirium. The study is conducted at two hospitals in Austria and involves patients who require mechanical ventilation and continuous sedation for more than six hours after surgery. BIS data will be collected continuously, but the readings will be blinded to the clinical team, meaning they will not influence patient care. Sedation will be managed using standard clinical practices. The findings aim to improve sedation management in ICUs.

Study Type

OBSERVATIONAL

Enrollment

Conditions

Sedation After Cardiac Surgery

Eligibility

Sex: ALLMin age: 18 Years

Medical Language ↔ Plain English

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

Outcomes

Primary Outcomes

Proportion of time spent in deep sedation

BIS \<50

Time frame: immediately after extubation or up to 48 hours of ICU sedation - whichever comes first

Secondary Outcomes

Duration of mechanical ventilation

Time frame: immediately after extubation

Incidence of pulmonary infection

any kind of pulmonary infection, including tracheobronchitis, pneumonia

Time frame: immediately after ICU discharge

Incidence of ICU delirium

assessed using CAM-ICU or ICDSC

Time frame: immediately after extubation

Time average of vasopressor dose

Time average of Noradrenaline dose

Time frame: immediately after extubation or after 48 hours of invasive ventilation

ICU and hospital LOS

in days

Time frame: immediately after hospital discharge

in hospital mortality

Time frame: immediately after hospital discharge

Incidence of BIS suppression events

episodes where the suppression ratio exceeds 10%, indicating potential over-sedation or EEG suppression