The Use of Intraoperative Neuromonitoring to Predict Post-Operative Delirium in Patients Undergoing Cardiac Surgery: A Retrospective Study
Omar Al Ta'ani1, Kathirvel Subramaniam1, Abdullah Al Qudah1, Vamsi Krishna Gorijala1, Senthilkumar Sadhasivam1, Keith Vogt1, Neelesh Nadkarni1, Victoria Kiselevskaya1, Parthasarathy Thirumala1
1University of Pittsburgh Medical Center
Objective:
To determine the diagnostic accuracy of intraoperative neuromonitoring (IONM) such as electroencephalogram (EEG) and somatosensory evoked potentials (SSEP) in predicting postoperative delirium in patients undergoing cardiac surgery.
Background:
Postoperative delirium can occur in up to 50% of elderly patients undergoing cardiac surgery, resulting in hospitalization and significant morbidity and mortality. Thus, early detection and intervention during surgery can be critical.
Design/Methods:
Clinical data from 510 patients undergoing cardiac surgery with IONM in 2019-2021 were retrospectively reviewed. Delirium was assessed multiple times using the Confusion Assessment Method (CAM)-ICU-7 delirium severity scale. Scores were categorized as 0-2: no delirium, 3-5: mild to moderate delirium, and 6-7: severe delirium. Significant IONM changes (either SSEP or EEG changes) were evaluated based on a visual review of SSEP and EEG data and documentation of changes during surgery.
Results:
Of the 507 patients undergoing cardiac surgery with IONM, 208 had delirium (41%). Significant IONM changes were noted in 185 patients, out of which 90 patients had delirium (48.6%). In contrast, 322 patients had no IONM changes during surgery, out of which 118 (36.6%) patients had delirium. Univariate analysis showed Patients who had an IONM change are 1.6 times more likely to experience postoperative delirium 1.6 (95% CI 1.1-2.36, p 0.008). To understand the effect of IONM changes on the severity of delirium we further analyzed the data. Of the 185 patients with IONM changes, 59 patients (31.9%) had (mild to moderate delirium) and 31 patients (16.7 %) had severe delirium. Patients who had an IONM change are 2.2 times more likely to experience severe delirium 2.2 (95 % CI 1.3-4.02, p 0.003).
Conclusions:
Abnormal IONM changes during cardiac surgery are associated with an increased risk of delirium and severe delirium. Further analysis can reveal that IONM can potentially be used for the early detection and prevention of postoperative delirium.