Changes in SedLine-derived processed electroencephalographic parameters during hypothermia in patients undergoing cardiac surgery with cardiopulmonary bypass

Objective Processed electroencephalography (pEEG) is used to monitor depth-of-anesthesia during cardiopulmonary bypass (CPB). The SedLine device has been recently introduced for pEEG monitoring. However, the effect of hypothermia on its parameters CPB unknown. Accordingly, we aimed investigate temperature-induced changes in SedLine-derived CPB. Design Prospective observational study. Setting Cardiac surgery operating theatre. Participants 28 patients undergoing elective cardiac with Interventions We continuously measured patient state index (PSI), suppression ratio (SR), bilateral spectral edge frequency (SEF) and temperature. linear mixed modelling fixed random effects study interactions between core Measurements main results During maintenance, median temperature was 32.1°C [interquartile range (IQR): 29.8–33.6] at end cooling 32.8°C (IQR: 30.1–34.0) rewarming initiation. For each degree Celsius change PSI either decreased by 0.8 points [95% confidence interval (CI): 0.7–1.0; p < 0.001] or increased 0.7 (95% CI: 0.6–0.8; 0.001). SR 2.9 2.3–3.4); 0.001) 2.2 1.7–2.7; rewarming. Changes SEF were not related Conclusions hypothermic CPB, led concordant PSI. Clinicians using monitoring should be aware these when interpreting values.