Comparison of Delirium Observation Screening Scale versus Single-Channel EEG after Cardiac Surgery in elderly patients: Brain Pro-TCT Study

Aim
Delirium in elderly patients following cardiac surgery is related to increased complications, hospitalization duration and mortality. Identifying delirium in high-risk patients is essential, yet hypoactive delirium is often overlooked in nurse-reported screening. Polymorphic delta waves, detectable through single-channel electroencephalography (SC-EEG), are linked to delirium.

This study compared screening with SC-EEG to the nurse-reported delirium observation screening scale (DOSS) for the detection of postoperative delirium and compare hospitalization duration for delirious patients.

Methods
In a prospective quasi-experimental study on a nursing ward, we compared DOSS screening (442 patients) with SC-EEG screening (462 patients) to identify postoperative delirium in cardiac surgery patients aged over 70 years. Delirium diagnoses were based on DSM-5 criteria. Analyses were corrected for baseline differences through multivariable regression analyses.

Results
The SC-EEG group had a higher delirium detection rate (20%) compared to the DOSS group (14%), p = 0.016. Unadjusted, a reduced median length of stay for delirious patients, identified with SC-EEG was observed (p = 0.002) but in multivariable analysis pneumonia and EuroSCORE II, rather than screening method were responsible (p = 0.54). Overall hospital stay was 0.11 [0.04 to 0.18] days shorter for patients in the SC-EEG cohort compared to those in the DOSS cohort, p = 0.002 (optional file 1).

Conclusion
SC-EEG screening increased the delirium detection rate after cardiac surgery. While a reduction in the length of stay for all patients in the SC-EEG cohort was modest, it can be relevant for high-volume cardiac surgery centres.