Effect of Hypothermia on BIS and PSI Correlation During Cardiopulmonary Bypass
Trial statusRecruiting
Trial phaseNot listed
Trial typeObservational
Biological sexAll
Age18-80
SponsorSakarya University
About this trial
The goal of this observational study is to evaluate whether hypothermia affects the relationship between electroencephalography-derived indices during cardiac surgery in adult patients undergoing cardiopulmonary bypass.
The main questions it aims to answer are:
Does the correlation between Bispectral Index (BIS) and Patient State Index (PSI) change between normothermic and hypothermic phases during cardiopulmonary bypass? How do BIS and PSI values change in response to decreasing body temperature?
Participants will:
Undergo standard general anesthesia for elective on-pump coronary artery bypass surgery Be monitored simultaneously with BIS and PSI devices during surgery Have data recorded at predefined temperature-based time points during cardiopulmonary bypass
Eligibility criteria
This trial does not accept healthy volunteersQualifiers
Age ≥18 years
Elective on-pump Coronary Artery Bypass Grafting (CABG) surgery
Planned use of general anesthesia
Written informed consent
Disqualifiers
Preexisting neurological disease
Use of medications affecting Electroencephalography (e.g., antiepileptics)
Severe hepatic dysfunction
Emergency surgery
Trial population
Adult patients undergoing elective on-pump coronary artery bypass grafting (CABG) with cardiopulmonary bypass at a single tertiary care center will be included. All participants will receive standard general anesthesia and perioperative management according to institutional protocols. Patients will be monitored intraoperatively with both Bispectral Index (BIS) and Patient State Index (PSI) devices, and data will be collected at predefined time points during normothermic, hypothermic, and rewarming phases of cardiopulmonary bypass.
Trial design
Design model
Cohort
Time perspective
Prospective
Treatments tested in this trial
Simultaneous BIS and PSI Monitoring
Other interventionThis observational study does not involve any experimental intervention. All participants will receive standard anesthesia and surgical care according to institutional protocols. The study focuses on simultaneous intraoperative monitoring using Bispectral Index (BIS) and Patient State Index (PSI) devices. Sensors for both monitors will be applied prior to induction of anesthesia, and values will be recorded at predefined time points during normothermic, hypothermic, and rewarming phases of cardiopulmonary bypass. No changes will be made to routine clinical management, and all treatments will be determined by the attending anesthesiologist.
Treatment groups
60 Participants
are divided into 1 treatment groupGroup A: Elective On-Pump CABG Patients Undergoing CPB1 intervention
Trial outcomes
Primary outcomes
1
Difference in Correlation Between Bispectral Index (BIS) and Patient State Index (PSI) Under Normothermic and Hypothermic Conditions
The primary outcome is the difference in Pearson correlation coefficients between BIS and PSI measured at predefined normothermic (36°C) and hypothermic (32°C) phases during cardiopulmonary bypass. Correlation coefficients will be calculated separately for each phase and compared using Fisher z-transformation to determine whether hypothermia alters the relationship between these indices.
Time frame
Intraoperative (during cardiopulmonary bypass at predefined time points)Secondary outcomes
1
Change in Bispectral Index (BIS) and Patient State Index (PSI) per Degree Celsius During Cooling and Rewarming
This outcome evaluates temperature-dependent changes in BIS and PSI during cooling and rewarming phases of cardiopulmonary bypass. The rate of change in each index per degree Celsius (Δindex/°C) will be calculated using repeated measurements across predefined temperature points. Linear mixed-effects models will be used to estimate the relationship between core temperature and index values while accounting for within-subject variability.
Time frame
Intraoperative (during cooling and rewarming phases of cardiopulmonary bypass)2
Effect of CPB Initiation on the Relationship Between Bispectral Index (BIS) and Patient State Index (PSI)
This outcome assesses the impact of cardiopulmonary bypass initiation on the relationship between BIS and PSI. Pearson correlation coefficients will be calculated at the pre-CPB stable normothermic time point (T4) and after CPB initiation under normothermic conditions (T5). The change in correlation between these two time points will be evaluated to determine whether initiation of CPB alters the association between the indices.
Time frame
Intraoperative (comparison of pre-CPB and post-CPB initiation time points)3
Agreement in Clinical Depth Categories Between Bispectral Index (BIS) and Patient State Index (PSI)
This outcome evaluates the agreement between BIS and PSI when classified into clinically relevant depth-of-anesthesia categories. BIS values will be categorized as \>60 (light), 40-60 (adequate), and \<40 (deep), while PSI values will be categorized as \>50 (light), 25-50 (adequate), and \<25 (deep). Agreement between the two indices will be assessed using Cohen's kappa coefficient. Comparisons will be performed separately for normothermic and hypothermic phases to determine whether temperature affects categorical agreement.
Time frame
Intraoperative (during predefined normothermic and hypothermic phases of cardiopulmonary bypass)Sponsors and contacts
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Source ClinicalTrials.gov