Multimodal Brain Monitoring in Cardiac Surgery and Postoperative Patient Outcomes

Abstract

Objective: To describe the occurrence of cerebral desaturation (≥10% decrease or <50% in regional cerebral oxygen saturation [rSO₂]), deep anesthetic states (processed electroencephalography patient state index [PSI] <25), and cerebral emboli load (high-intensity transient signals [HITS]) using multimodal neuromonitoring.

Design: Retrospective single-center cohort study.

Setting: University-affiliated cardiology center.

Participants: 374 adult patients undergoing cardiac surgery with cardiopulmonary bypass (CPB).

Intervention: None.

Measurements and main results: Patients were categorized into 4 cerebral states based on rSO₂ desaturation and PSI <25. In a subsample of 175 patients with transcranial Doppler (TCD) monitoring, patients were further classified into 8 groups based on desaturation, PSI <25, and HITS severity. Logistic regression and analysis of variance were used to examine associations between cerebral states and outcomes, including CPB separation, duration of ventilation, length of intensive care unit (ICU)/hospital stay, and mortality. Patients with desaturation and PSI <25 (state 4) had a higher EuroSCORE II, more comorbidities, longer CPB/aortic clamping times, and worse postoperative outcomes, including extended ICU and hospital stays. Within the TCD subsample, those with moderate-to-severe HITS alongside desaturation and PSI <25 experienced the poorest outcomes, such as prolonged hospitalization and difficult CPB separation. Multivariable models confirmed associations with adverse outcomes, although some effects were attenuated after adjustment.

Conclusions: Multimodal neuromonitoring during cardiac surgery identified high-risk patients, particularly those with concurrent desaturation and burst suppression, who had significantly worse outcomes. Targeted interventions for these patients could improve outcomes. Future studies should investigate optimal management strategies for this high-risk group.

Keywords: brain monitoring, postoperative outcomes; cardiopulmonary bypass; processed electroencephalogram; regional cerebral oxygen saturation.