Use of the Patient State Index (PSI) to assist in the diagnosis of perioperative neurological injury and brain death

We present a series of three postoperative cases that were admitted to a cardiothoracic intensive care unit (ICU) after major surgery. Due to the possible presence of residual postoperative neuromuscular blockade after surgery, a processed electroencephalograph (EEG) was applied prior to starting sedation. This was markedly abnormal in all three cases, and not in keeping with the residual anesthesia. The patients were immediately transported for a CT scan. In all three cases there was severe neurological injury incompatible with survival and end of life decisions were made. Although the utility of quantitative EEG technology, like the Bispectral index (BIS) or Patient State Analyzer (PSA), is becoming better defined in the operating room, the role in the ICU is less clear. We propose that the ICU use of the PSA 4000 may have affected our decision weighing the risk versus benefit of transporting a fresh postoperative case to the radiology suite, expedited the neurological diagnosis, and may have reduced overall ICU resource utilization.