Abstract
AbstractObjectivePatients with acute lung or heart failure can experience hypoxic ischemic brain injury resulting in neurovascular unit (NVU) dysfunction. The NVU couples brain activity and perfusion. Extracorporeal membrane oxygenation (ECMO) is used for refractory lung and/or heart failure and often necessitates sedation, obfuscating neurological assessments. We hypothesized that combining cerebral electrographic activity and perfusion monitoring can detect brain injury in adults undergoing ECMO.MethodsFast Fourier transformation was used to identify fast (α+β) and slow (δ) power bands from cEEG. Diffuse correlation spectroscopy (DCS) measured blood flow index (BFI), a surrogate of perfusion, daily in adults undergoing ECMO. Correlations between α+β/δ ratio (ABDR) and BFI were compared between patients who were grouped into brain-injured and uninjured groups by neurologic exam and neuroimaging findings.ResultsTen patients (21-78 years old, five females, five brain-injured) underwent cEEG and DCS monitoring. Sixty-eight monitoring sessions (average 127 minutes/session) were analyzed. ABDR-BFI correlation was significantly higher in uninjured patients than brain-injured ones. Sedation did not significantly impact CBF-power band correlation.ConclusionsBrain-injured patients exhibited significantly less correlation between brain activity and perfusion, possibly as a result of NVU dysfunction.SignificanceABDR-BFI correlation can be measured continuously and noninvasively at the bedside and may represent a marker of NVU dysfunction.HighlightsQuantitative EEG and diffuse correlative spectroscopy can be used to measure markers of brain injury noninvasively, continuously, and at the bedside.Decreased ABDR-BFI correlation may be a marker of neurovascular decoupling in patients with hypoxic ischemic brain injury.ABDR-BFI correlation may be independent of analgosedation, which is used heavily in patients undergoing ECMO.
Publisher
Cold Spring Harbor Laboratory