(716) Evaluating TCD and Alternative Neuromonitoring Techniques in Cardiac Surgery

Introduction: Cerebral blood flow changes during Cardiopulmonary Bypass (CPB) are associated with neurological adverse events. Noninvasive neuromonitoring like Transcranial Doppler (TCD) Near Infrared Regional Saturation (NIRS), Xenon clearance, and Central Retinal Artery Doppler has been widely used perioperatively. We report findings of a systematic review to compare TCD with other neuromonitoring modalities during cardiac surgery with CPB.

Methods: Five databases (MEDLINE Ovid, PubMed, Embase, Web of Science, Cochrane Library) were searched systematically for English articles studies involving adult patients undergoing cardiac surgery with CPB. Conference abstracts, books, review articles, and systematic reviews were excluded. Primary outcomes included stroke, seizures, and cognitive decline. Data were collected on patient characteristics, details of surgery, and CPB.

Results: 26 of 428 studies screened were reviewed for final data extraction with 14 studies on cerebral autoregulation (9 TCD vs NIRS, and 5 compared jugular bulb oximeter, FGD-PET, two-channel EEG, BIS, regional cerebral venous oxygen saturation),8 on cerebral blood flow modification( 2 compared Xenon clearance and 2 Kay Schmidt method, 2 compared NIRS, and 2 CRAD with TCD),4 on emboli monitoring(TEE, CRAD, SB 100 level and coulter counter method) and 7 studies evaluating multimodal neuromonitoring including TCD. Neurological outcomes were reported in 9 of 26 (35%) of the studies. The pooled correlation coefficient of comparative TCD-based metrics with other methods was 0.60( data from 14/26 studies).

Conclusions: This systematic review underscores the variability in neuromonitoring methods and parameters in cardiac surgery with cardiopulmonary bypass. Multimodal neuromonitoring may be the most effective approach for optimal neurological monitoring during cardiac surgery and should be investigated further.