Accuracy of a Cerebral Oximeter in Healthy Volunteers under Conditions of Isocapnic Hypoxia 

1998 ◽  
Vol 88 (1) ◽  
pp. 58-65 ◽  
Author(s):  
Lindsey C. Henson ◽  
Carolyn Calalang ◽  
John A. Temp ◽  
Denham S. Ward
Keyword(s):  
Infrared Spectroscopy ◽  
Oxygen Saturation ◽  
Healthy Volunteers ◽  
Near Infrared Spectroscopy ◽  
Near Infrared ◽  
Cerebral Oxygenation ◽  
Jugular Bulb ◽  
Wide Range ◽  
Cerebral Oximeter ◽  
End Tidal

Background A cerebral oximeter measures oxygen saturation of brain tissue noninvasively by near infrared spectroscopy. The accuracy of a commercially available oximeter was tested in healthy volunteers by precisely controlling end-tidal oxygen (P[ET]O2) and carbon dioxide (P[ET]CO2) tensions to alter global cerebral oxygen saturation. Methods In 30 healthy volunteers, dynamic end-tidal forcing was used to produce step changes in P[ET]O2 resulting in arterial saturation ranging from approximately 70% to 100% under conditions of controlled normocapnia (each person's resting P[ET]CO2) or hypercapnia (resting plus 7-10 mmHg). Blood arterial (SaO2) and jugular bulb venous (S[jv]O2) saturations during each P(ET)O2 interval were determined by co-oximetry. The cerebral oximeter reading (rSO2) and an estimated jugular venous saturation (S[jv]O2), derived from a combination of SaO2 and rSO2, were compared with the measured S(jv)O2. Results The S(jv)O2 was significantly higher with hypercapnia than with normocapnia for the same SaO2. The rSO2 and S(jv)O2 were both highly correlated with S(jv)O2 for individual volunteers (mean r2 = 0.91 for each relation); however, the slopes and intercepts varied widely among volunteers. In three of them, the cerebral oximeter substantially underestimated the measured S(jv)O2. Conclusions During isocapnic hypoxia in healthy persons, cerebral oxygenation as estimated by near infrared spectroscopy precisely tracks changes in measured S(jv)O2 within individuals, but the relation exhibits a wide range of slopes and intercepts. Therefore the clinical utility of the device is limited to situations in which tracking trends in cerebral oxygenation would be acceptable.

Near-Infrared Spectroscopy Monitoring of Cerebral Oxygenation and Influencing Factors in Neonates from High-Altitude Areas

Neonatology ◽  
2021 ◽  
pp. 1-6
Author(s):  
Bi Ze ◽  
Lili Liu ◽  
Ge Sang Yang Jin ◽  
Minna Shan ◽  
Yuehang Geng ◽  
...  
Keyword(s):  
Heart Disease ◽  
Infrared Spectroscopy ◽  
Brain Injury ◽  
Oxygen Saturation ◽  
High Altitude ◽  
Near Infrared Spectroscopy ◽  
Near Infrared ◽  
Cerebral Oxygenation ◽  
Low Altitude ◽  
Normal Neonates

<b><i>Background:</i></b> Accurate detection of cerebral oxygen saturation (rSO<sub>2</sub>) may be useful for neonatal brain injury prevention, and the normal range of rSO<sub>2</sub> of neonates at high altitude remained unclear. <b><i>Objective:</i></b> To compare cerebral rSO<sub>2</sub> and cerebral fractional tissue oxygen extraction (cFTOE) at high-altitude and low-altitude areas in healthy neonates and neonates with underlying diseases. <b><i>Methods:</i></b> 515 neonates from low-altitude areas and 151 from Tibet were enrolled. These neonates were assigned into the normal group, hypoxic-ischemic encephalopathy (HIE) group, and other diseases group. Near-infrared spectroscopy was used to measure rSO<sub>2</sub> in neonates within 24 h after admission. The differences of rSO<sub>2</sub>, pulse oxygen saturation (SpO<sub>2</sub>), and cFTOE levels were compared between neonates from low- and high-altitude areas. <b><i>Results:</i></b> (1) The mean rSO<sub>2</sub> and cFTOE levels in normal neonates from Tibet were 55.0 ± 6.4% and 32.6 ± 8.5%, significantly lower than those from low-altitude areas (<i>p</i> &#x3c; 0.05). (2) At high altitude, neonates with HIE, pneumonia (<i>p</i> &#x3c; 0.05), anemia, and congenital heart disease (<i>p</i> &#x3c; 0.05) have higher cFTOE than healthy neonates. (3) Compared with HIE neonates from plain areas, neonates with HIE at higher altitude had lower cFTOE (<i>p</i> &#x3c; 0.05), while neonates with heart disease in plateau areas had higher cFTOE than those in plain areas (<i>p</i> &#x3c; 0.05). <b><i>Conclusions:</i></b> The rSO<sub>2</sub> and cFTOE levels in normal neonates from high-altitude areas are lower than neonates from the low-altitude areas. Lower cFTOE is possibly because of an increase in blood flow to the brain, and this may be adversely affected by disease states which may increase the risk of brain injury.

Cerebral oxygenation measured by near-infrared spectroscopy: Comparison with jugular bulb oximetry

1996 ◽  
Vol 61 (3) ◽  
pp. 930-934 ◽  
Author(s):  
Piers E.F. Daubeney ◽  
Sally N. Pilkington ◽  
Ellen Janke ◽  
Gareth A. Charlton ◽  
David C. Smith ◽  
...  
Keyword(s):  
Infrared Spectroscopy ◽  
Near Infrared Spectroscopy ◽  
Near Infrared ◽  
Cerebral Oxygenation ◽  
Jugular Bulb

scholarly journals Near-Infrared Spectroscopy for the Evaluation of Anesthetic Depth

2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Gabriela Hernandez-Meza ◽  
Meltem Izzetoglu ◽  
Mary Osbakken ◽  
Michael Green ◽  
Kurtulus Izzetoglu
Keyword(s):  
Infrared Spectroscopy ◽  
Near Infrared Spectroscopy ◽  
Near Infrared ◽  
Cerebral Oxygenation ◽  
Standard Of Care ◽  
Functional Near Infrared Spectroscopy ◽  
Gold Standard Method ◽  
Anesthetic Drugs ◽  
Sedation Monitoring ◽  
End Tidal

The standard-of-care guidelines published by the American Society of Anesthesiologists (ASA) recommend monitoring of pulse oximetry, blood pressure, heart rate, and end tidal CO2during the use of anesthesia and sedation. This information can help to identify adverse events that may occur during procedures. However, these parameters are not specific to the effects of anesthetics or sedatives, and therefore they offer little, to no, real time information regarding the effects of those agents and do not give the clinician the lead-time necessary to prevent patient “awareness.” Since no “gold-standard” method is available to continuously, reliably, and effectively monitor the effects of sedatives and anesthetics, such a method is greatly needed. Investigation of the use of functional near-infrared spectroscopy (fNIRS) as a method for anesthesia or sedation monitoring and for the assessment of the effects of various anesthetic drugs on cerebral oxygenation has started to be conducted. The objective of this paper is to provide a thorough review of the currently available published scientific studies regarding the use of fNIRS in the fields of anesthesia and sedation monitoring, comment on their findings, and discuss the future work required for the translation of this technology to the clinical setting.

scholarly journals Changes in cerebral oxygen saturation and cerebral blood flow velocity under mild +Gz hypergravity

2019 ◽  
Vol 127 (1) ◽  
pp. 190-197 ◽  
Author(s):  
Toru Konishi ◽  
Takuya Kurazumi ◽  
Tomokazu Kato ◽  
Chiharu Takko ◽  
Yojiro Ogawa ◽  
...  
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Infrared Spectroscopy ◽  
Oxygen Saturation ◽  
Near Infrared Spectroscopy ◽  
Near Infrared ◽  
Cerebral Oxygenation ◽  
Cerebral Oxygen Saturation ◽  
Cerebral Oxygen ◽  
Regional Cerebral Oxygen Saturation

We previously reported that cerebral blood flow (CBF) was reduced by even mild +Gz hypergravity. Regional cerebral oxygen saturation as measured by near-infrared spectroscopy (C-rSO2) has been widely used to detect cerebral ischemia in clinical practice. For example, decreases in C-rSO2reflect reduced CBF or arterial oxygen saturation. Thus it was hypothesized that C-rSO2would decrease in association with reduced CBF during mild hypergravity. To test this hypothesis, we measured CBF velocity by transcranial Doppler ultrasonography and C-rSO2during mild +Gz hypergravity while participants were in a sitting position. Among 17 male participants, 15 completed 21 min of exposure to +1.5 Gz generated by short-arm centrifuge. C-rSO2and mean CBF velocity in the middle cerebral artery (MCBFVMCA) during centrifugation were averaged every 5 min and compared with pre-hypergravity (+1.0 Gz). C-rSO2did not change significantly throughout centrifugation, although MCBFVMCAgradually decreased from the beginning (−1.2% at 0–5 min), and significantly decreased at 5–10 min (−4.8%), 10–15 min (−6.7%), and 15–20 min (−7.4%). Contrary to our hypothesis, decreases in C-rSO2were not detected, despite reductions in CBF velocity during hypergravity. Since some assumptions, such as unaltered arteriovenous volume ratio, hemoglobin concentration, extracranial blood flow, and brain activity, need to be satisfied to monitor cerebral ischemia by C-rSO2, the present results suggest that these necessary assumptions for near-infrared spectroscopy are not always applicable, and that cerebral oxygenation may not precisely reflect decreases in CBF under mild +Gz hypergravity.NEW & NOTEWORTHY To our knowledge, this is the first study to evaluate simultaneously cerebral oxygenation monitored by near-infrared spectroscopy and cerebral blood flow (CBF) monitored by transcranial Doppler under +1.5 Gz hypergravity. Contrary to our hypothesis, there was no significant correlation between CBF velocity and regional cerebral oxygen saturation (C-rSO2). However, an incomplete case nearly involving syncope suggests the possibility that C-rSO2can detect a remarkable decrease in CBF with development of presyncope during +Gz hypergravity.

scholarly journals Shedding light on the adult brain: a review of the clinical applications of near-infrared spectroscopy

2011 ◽  
Vol 369 (1955) ◽  
pp. 4452-4469 ◽  
Author(s):  
Martin Smith
Keyword(s):  
Infrared Spectroscopy ◽  
Near Infrared Spectroscopy ◽  
Near Infrared ◽  
Cerebral Oxygenation ◽  
Neurological Complications ◽  
Adult Brain ◽  
Rapid Expansion ◽  
Time Resolved ◽  
Clinical Scenarios ◽  
Wide Range

Near-infrared spectroscopy (NIRS) has potential as a non-invasive brain monitor in a wide range of clinical scenarios. In the last decade, there has been a rapid expansion of clinical experience using NIRS to monitor cerebral oxygenation, particularly in cardiac surgery, where there is some evidence that NIRS-guided brain protection protocols might lead to a reduction in peri-operative neurological complications. There are no data to support the wider application of NIRS to monitor cerebral oxygenation during routine anaesthesia and surgery, and its application in brain injury, where it might be expected to have a key monitoring role, is as yet undefined. Technological developments, including the introduction of broadband and time-resolved spectrometers that are capable of reliably measuring changes in oxidized cytochrome c oxidase, offer real potential for a single NIRS-based device to provide multi-site, regional monitoring of cerebral metabolic status as well as oxygenation and haemodynamics.

scholarly journals Acupressure at the Meridian Acupoint Xiyangguan (GB33) Influences Near-Infrared Spectroscopic Parameters (Regional Oxygen Saturation) in Deeper Tissue of the Knee in Healthy Volunteers

2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
Gerhard Litscher ◽  
Michael Ofner ◽  
Wei He ◽  
Lu Wang ◽  
Ingrid Gaischek
Keyword(s):  
Infrared Spectroscopy ◽  
Pilot Study ◽  
Oxygen Saturation ◽  
Healthy Volunteers ◽  
Therapeutic Effect ◽  
Near Infrared Spectroscopy ◽  
Near Infrared ◽  
Peripheral Tissue ◽  
Controlled Study ◽  
Regional Oxygen Saturation

Up to now, it is still unknown whether microcirculation of deeper peripheral tissue (knee) can be modulated by acupuncture or acupressure on a meridian acupoint. The goal of this pilot study was to investigate possible effects of acupressure at the Xiyangguan acupoint (GB33) on the regional oxygen saturation of the deeper knee tissues by near-infrared spectroscopy (NIRS). Twelve healthy volunteers with a mean age of23.8±1.6years were investigated. Acupressure stimulation was performed for 5 minutes at the Xiyangguan acupoint. The results of the controlled study showed a significant increase of the values of regional oxygen saturation on the stimulated side of the knee (P=0.033), whereas the opposite side on the same knee showed insignificant changes. These results may serve as a valuable basis for monitoring a possible therapeutic effect (e.g., after Khalifa therapy) in patients with knee problems.

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