How cooling during cardiopulmonary bypass changes BIS and PSI brain monitor readings

Effect of Hypothermia on the Correlation Between Bispectral Index (BIS) and Patient State Index (PSI) During Cardiopulmonary Bypass

Observational Sakarya University · NCT07508579

This will test whether cooling the body during on-pump coronary bypass changes how two brain monitors (BIS and PSI) agree in adults having elective CABG.

Quick facts

Study typeObservational
Enrollment60 (estimated)
Ages18 Years to 80 Years
SexAll
SponsorSakarya University Academic / other
Locations1 site (Sakarya, Serdivan)
Trial IDNCT07508579 on ClinicalTrials.gov

What this trial studies

This prospective observational study follows adults having elective on-pump coronary artery bypass grafting who receive routine general anesthesia. BIS and PSI sensors will record processed EEG continuously, with data captured at predefined temperature-based time points representing normothermia (36°C), hypothermia (32°C), and rewarming phases of cardiopulmonary bypass. The primary analysis will compare the correlation between BIS and PSI at the normothermic and hypothermic reference points, while anesthetic management and physiological variables are kept within routine clinical target ranges to reduce confounding. Secondary analyses will describe how each index changes with decreasing temperature and assess agreement across clinically relevant depth-of-anesthesia ranges.

Who should consider this trial

Good fit: Adults (age ≥18) scheduled for elective on-pump coronary artery bypass grafting under general anesthesia who can give written informed consent and have no preexisting neurological disease are ideal candidates.

Not a fit: Patients undergoing emergency or off-pump cardiac surgery, those with preexisting neurological disorders, those on EEG-affecting medications, or those unable to provide usable monitor signals are unlikely to benefit.

Why it matters

Potential benefit: If successful, the results could help clinicians interpret EEG-based depth monitoring during cooling and rewarming and reduce the risk of under- or over-sedation during cardiac bypass.

How similar studies have performed: Prior studies have shown moderate-to-high correlation between BIS and PSI under normal temperatures, but the effect of hypothermia during cardiopulmonary bypass remains largely untested.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* Age ≥18 years
* Elective on-pump Coronary Artery Bypass Grafting (CABG) surgery
* Planned use of general anesthesia
* Written informed consent

Exclusion Criteria:

* Preexisting neurological disease
* Use of medications affecting Electroencephalography (e.g., antiepileptics)
* Severe hepatic dysfunction
* Emergency surgery
* Inadequate signal quality for anesthesia depth monitoring

Where this trial is running

Sakarya, Serdivan

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions Cardiopulmonary BypassHypothermiaAnesthesiaDepth of Anesthesia MonitoringBispectral IndexPatient State IndexProcessed EEGCardiac Surgery
Last reviewed 2026-06-10 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.