Cerebral blood flow is decoupled from blood pressure and linked to EEG bursting after resuscitation from cardiac arrest

Abstract

Abstract:In the present study, we have developed a multi-modal instrument that combines laser speckle imaging, arterial blood pressure, and electroencephalography (EEG) to quantitatively assess cerebral blood flow (CBF), mean arterial pressure (MAP), and brain electrophysiology before, during, and after asphyxial cardiac arrest (CA) and resuscitation. Using the acquired data, we quantified the time and magnitude of the CBF hyperemic peak and stabilized hypoperfusion after resuscitation. Furthermore, we assessed the correlation between CBF and MAP before and after stabilized hypoperfusion. Finally, we examined when brain electrical activity resumes after resuscitation from CA with relation to CBF and MAP, and developed an empirical predictive model to predict when brain electrical activity resumes after resuscitation from CA. Our results show that: 1) more severe CA results in longer time to stabilized cerebral hypoperfusion; 2) CBF and MAP are coupled before stabilized hypoperfusion and uncoupled after stabilized hypoperfusion; 3) EEG activity (bursting) resumes after the CBF hyperemic phase and before stabilized hypoperfusion; 4) CBF predicts when EEG activity resumes for 5-min asphyxial CA, but is a poor predictor for 7-min asphyxial CA. Together, these novel findings highlight the importance of using multimodal approaches to investigate CA recovery to better understand physiological processes and ultimately improve neurological outcome.

Spreading depolarization and repolarization during cardiac arrest as an ultra-early marker of neurological recovery in a preclinical model

“…The animal model of ACA and resuscitation employed in this study has been described previously [41][42][43][44]48 and is summarized in Fig. 1.…”

“…LSI is an established technique to measure blood flow in preclinical models and humans, [50][51][52] including CA studies. 44,53,54 SFDI is an established technique 55,56 that enables separate quantification of the diffuse optical absorption and scattering coefficients of tissue. The absorption coefficient, when measured at multiple nearinfrared wavelengths, provides information regarding concentrations of oxygenated and deoxygenated hemoglobin (ctHbO2, ctHb, respectively) in tissue.…”

“…[33][34][35][36][37][38][39] Additionally, via measurement of tissue scattering, optical techniques can also interrogate neuronal damage caused by cytotoxic edema and dendritic beading. 24,40 In this study, we used a preclinical model of asphyxial CA (ACA) and cardiopulmonary resuscitation (CPR), 41,42 along with an ECoG and optical imaging platform 43,44 , to characterize SD during ACA and repolarization (RP) post-CPR. We show that earlier SD and earlier RP are both associated with better neurological outcome.…”

High-speed quantitative optical imaging of absolute metabolism in the rat cortex

“…Ten male Wistar rats (weight ~300-400 g) were imaged for this study, and the animal preparation procedures are described in our previous publications [7,8,13,14]. Before the experiment, all rats were endotracheally intubated under isoflurane anesthesia.…”

“…Recently, we demonstrated that the combination of Spatial Frequency Domain Imaging (SFDI) and Laser Speckle Imaging (LSI)) can quantify tissue metabolic changes with high spatial and temporal resolution [6]. We also recently applied high-speed LSI [7] and SFDI [8] to measure perfusion, oxygenation, and tissue scattering in the brain in a cardiac arrest (CA) model of global cerebral ischemia. The capability of our rapid multimodal SFDI+LSI system to image blood flow and hemoglobin concentration simultaneously enables high-speed measurement of CMRO 2 [9].…”