Perfusion Enhancement with Respiratory Impedance After Stroke (PERI-Stroke)

Abstract

Intrathoracic pressure influences cardiac output and may affect cerebral blood flow (CBF). We aimed to quantify the cerebral hemodynamic response to intrathoracic pressure reduction in patients with acute ischemic stroke using a noninvasive respiratory impedance (RI) device. We assessed low-level (6 cm H 2 O) and high-level (12 cm H 2 O) RI in 17 spontaneously breathing patients within 72 h of anterior circulation acute ischemic stroke. Average age was 65 years, and 35% were female. Frontal lobe tissue perfusion and middle cerebral artery velocity (MCAv) were continuously monitored with optical diffuse correlation spectroscopy (DCS) and transcranial Doppler ultrasound, respectively. High-level RI resulted in a 7% increase in MCAv (p = 0.004). MCAv varied across all studied levels (baseline vs low-level vs high-level, p = 0.006), with a significant test of trend (p = 0.002). Changes were not seen in DCS measured tissue perfusion by nonparametric pairwise comparison. Mixed effects regression analysis identified a small increase in both MCAv (low-level RI: β 2.1, p < 0.001; high-level RI: β 5.0, p < 0.001) and tissue-level flow (low-level RI: β 5.4, p < 0.001; high-level RI: β 5.9, p < 0.001). There was a small increase in mean arterial pressure during low-level and high-level RI, 4% (p = 0.013) and 4% (p = 0.017), respectively. End-tidal CO 2 remained stable throughout the protocol. RI was well tolerated. Manipulating intrathoracic pressure via noninvasive RI was safe and produced a small but measurable increase in cerebral perfusion in acute ischemic stroke patients. Future studies are warranted to assess whether RI is feasible and tolerable for prolonged use in hyperacute stroke management.

Optical imaging and spectroscopy for the study of the human brain: status report

“… 390 – 392 More recently, new optical devices have allowed the monitoring of novel therapeutic approaches intended to increase blood flow and oxygenation in the ischemic penumbra. 393 – 398 Moreover, exciting new work suggests optics may be sensitive to ICP. This growing area of research is discussed more in depth in Sec.…”

Hybrid diffuse optical monitoring of hemodynamic changes following acute cerebral ischemia in a porcine model

“…However, the cranial geometry of these models is significantly different from the adult human head in absolute size. Human studies have also been performed with a variety of NIRS techniques [21][22][23][24][25][26][27][28][29][30][31][32][33] but these studies are ethically and practically limited. In this report, we focus on monitoring the evolving injury in the first hours following an ischemic insult in a large animal porcine model.…”

Translation of a diffuse optical system for monitoring neurocritical patients

“…For example, diffuse optics have been shown to provide relevant clinical information for critically-ill neonates [32,33], including during cardiac surgeries to treat heart defects [15,34,35]. Additionally, many authors have explored the use of diffuse optics to assess the cerebral hemodynamics during different cerebrovascular interventions, such as during carotid endarterectomy 1 [36][37][38], during thrombolytic treatments for stroke [39], during head-of-bed manipulations [40][41][42], during cardiopulmonary resuscitation [43], and others [44][45][46]. Diffuse optics have also been used to monitor cerebral auto-regulation 2 , both in healthy and critically ill subjects [18,25,47], as well for assesssing the critical closing pressure of the cerebral circulation 3 [26].…”

“…Either FD-DOS or TD-DOS can be combined with diffuse correlation spectroscopy (DCS) for measurements of CBF and metabolism. The combination of DCS and FD/TD-DOS has been explored to monitor patients in several clinical scenarios, e.g., for neonatal monitoring [15,[32][33][34]63], during cerebrovascular interventions [37,38,40,41,45,142], as well as for monitoring of neurocritical patients [47,49,50]. However, these studies mostly focused on the effects of specific events and interventions.…”