title: Quantifying the cerebral metabolic rate of oxygen by combining diffuse correlation spectroscopy and time-resolved near-infrared spectroscopy.
abstract: Preterm infants are highly susceptible to ischemic brain injury; consequently, continuous bedside monitoring to detect ischemia before irreversible damage occurs would improve patient outcome. In addition to monitoring cerebral blood flow (CBF), assessing the cerebral metabolic rate of oxygen (CMRO2) would be beneficial considering that metabolic thresholds can be used to evaluate tissue viability. The purpose of this study was to demonstrate that changes in absolute CMRO2 could be measured by combining diffuse correlation spectroscopy (DCS) with time-resolved near-infrared spectroscopy (TR-NIRS). Absolute CBF was determined using bolus-tracking TR-NIRS to calibrate the DCS measurements. Cerebral venous blood oxygenation (SvO2) was determined by multiwavelength TR-NIRS measurements, the accuracy of which was assessed by directly measuring the oxygenation of sagittal sinus blood. In eight newborn piglets, CMRO2 was manipulated by varying the anesthetics and by injecting sodium cyanide. No significant differences were found between the two sets of SvO2 measurements obtained by TR-NIRS or sagittal sinus blood samples and the corresponding CMRO2 measurements. Bland-Altman analysis showed a mean CMRO2 difference of 0.0268 ± 0.8340 mLO2/100 g/min between the two techniques over a range from 0.3 to 4 mL O2/100 g/min.
authors: Lawson Health Research Institute, Imaging Division, London, Ontario, N6A 4V2, Canada.
authors: Kyle
authors: K
authors: Verdecchia
authors: Mamadou
authors: M
authors: Diop
authors: Ting-Yim
authors: TY
authors: Lee
authors: Keith
authors: K
authors: St Lawrence
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D001921:Brain / Q000378:metabolism*; D002560:Cerebrovascular Circulation; D006801:Humans; D007231:Infant, Newborn; D023421:Models, Animal; D008991:Monitoring, Physiologic / Q000379:methods; D055620:Optical Phenomena; D010100:Oxygen / Q000097:blood / Q000378:metabolism*; D019265:Spectroscopy, Near-Infrared / Q000379:methods*; D013057:Spectrum Analysis / Q000379:methods*; D034421:Sus scrofa
chemical_list: D010100:Oxygen