Validation of frontal near-infrared spectroscopy as noninvasive bedside monitoring for regional cerebral blood flow in brain-injured patients

Abstract

<jats:sec> <jats:title>Object</jats:title> <jats:p>Near-infrared spectroscopy (NIRS) offers noninvasive bedside measurement of direct regional cerebral arteriovenous (mixed) brain oxygenation. To validate the accuracy of this monitoring technique, the authors analyzed the statistical correlation of NIRS and CT perfusion with respect to regional cerebral blood flow (CBF) measurements.</jats:p></jats:sec> <jats:sec> <jats:title>Methods</jats:title> <jats:p>The authors retrospectively reviewed all cases in which NIRS measurements were obtained at a single, academic neurointensive care unit from February 2008 to June 2011 in which CT perfusion was performed at the same time as NIRS data was collected. Regions of interest were obtained 2.5 cm below the NIRS bifrontal scalp probe on CT perfusion with an average volume between 2 and 4 ml, with mean CBF values used for purposes of analysis. Linear regression analysis was performed for NIRS and CBF values.</jats:p></jats:sec> <jats:sec> <jats:title>Results</jats:title> <jats:p>The study included 8 patients (2 men, 6 women), 6 of whom suffered subarachnoid hemorrhage, 1 ischemic stroke, and 1 intracerebral hemorrhage and brain edema. Mean CBF measured by CT perfusion was 61 ml/100 g/min for the left side and 60 ml/100 g/min for the right side, while mean NIRS values were 75 on the right and 74 on the left. Linear regression analysis demonstrated a statistically significant probability value (p &lt; 0.0001) comparing NIRS frontal oximetry and CT perfusion–obtained CBF values.</jats:p></jats:sec> <jats:sec> <jats:title>Conclusions</jats:title> <jats:p>The authors demonstrated a linear correlation for frontal NIRS cerebral oxygenation measurements compared with regional CBF on CT perfusion imaging. Thus, frontal NIRS cerebral oxygenation measurement may serve as a useful, noninvasive, bedside intensive care unit monitoring tool to assess brain oxygenation in a direct manner.</jats:p></jats:sec>

Controlled transient hypercapnia: a novel approach for the treatment of delayed cerebral ischemia after subarachnoid hemorrhage?

“…13,18 NIRS measures the content of oxygenated hemoglobin in tissues and depends on arterial partial pressure of oxygen (PaO 2 ) on the one side 1,14 and CBF on the other side. 16,21,22 Transcutaneous NIRS measurement has been validated by comparison with xenon and perfusion CT. 21,22 PaCO 2 was the only variable parameter in the present study. In particular, the arterial oxygen saturation and PaO 2 remained constant.…”

Letter by Freeman and Taussky Regarding Article, “Near Infrared Spectroscopy for the Detection of Desaturations in Vulnerable Ischemic Brain Tissue: A Pilot Study at the Stroke Unit Bedside”

“…The disadvantages of NIRS technology is that it provides only "regional" saturation of oxygen probe information, similar to other, typically invasive, neurointensive care unit probes such as Licox PbO 2 , intracranial pressure probes, or Hemedex cerebral blood flow sensors. Despite these limitations, we believe that NIRS probes have the potential to be useful for managing patients with stroke and NIRS regional saturation of oxygen correlates with CT perfusion-derived regional cerebral blood flow 2 …”

Cerebral blood flow and cerebral saturation in head injury. Comparison of CT perfusion and cerebral near-infrared oxymetry

“…Одними из наиболее информативных методов, позволяющих выявить ишемию ГМ, являются пер-фузионная компьютерная томография (КТ) и инфра-красная церебральная спектроскопия [2].…”

“…Учитывая эти факты, взаимосвязь между уровнем сатурации ткани ГМ (cerebral tissue oxygen saturation -SctO 2 ) и состоянием микроциркуляции в ГМ представляется весьма вероятной. Вместе с тем, исследования по данной проблеме малочисленны [10] и касаются лишь острого нарушения кровооб-ращения ГМ [2].…”

“…При исследовании взаимосвязи между уровнем оксигенации и параметрами перфузионой КТ ГМ у пациентов при цереброваскулярных заболеваниях, напротив, установлена достоверная зависимость между SсtO 2 и rCBF (Р<0,0001) и не выявлена линей-ная корреляция с другими параметрами перфузии ГМ [2].…”