title: Tissue Monitoring with Three-Wavelength Light Emitting Diode-Based Near-Infrared Spectroscopy.
abstract: BackgroundFlap monitoring with near-infrared spectroscopy (NIRS) facilitates early detection of vascular compromise. However, standard NIRS devices that employ two wavelengths of light to assess tissue oxygenation (StO2) are susceptible to artifact from background noise and demonstrate significant variability in the clinical setting. As the number of wavelengths detected by a NIRS device is increased, the precision of StO2measurements can be improved and additional chromophores other than oxyhemoglobin and deoxyhemoglobin can be measured. A three-wavelength light emitting diode NIRS device (Artinis, Zetten, the Netherlands) that also detects cytochromeaa3, a measure of intracellular oxygen demand, was compared with the standard two-wavelength device commonly used for flap monitoring (ViOptix device, ViOptix Inc., Freemont, CA) to determine if there is an improvement in the precision of tissue oxygen measurements.MethodsViOptix and Artinis were applied to the forearms of human volunteers (n= 15) and a blood pressure cuff was placed around the upper arm to occlude arterial and venous flow. StO2measurements were obtained from both devices. Artinis also yielded cytochromeaa3oxidation state measurements.ResultsStO2measurements from both devices were proportionate during ischemia (R2= 0.79,p< 0.01). Monte Carlo stimulation showed Artinis outperformed ViOptix (p< 0.01) as a measure of change in StO2during ischemia. Artinis did not detect a reduction in cytochromeaa3associated with the decrease in StO2during ischemia.ConclusionThe addition of a third wavelength to NIRS monitoring may improve the precision of StO2trend monitoring. However, the three-wavelength device lacked the sensitivity to reliably measure changes in cytochromeaa3.
authors.affiliation: Department of Plastic Surgery, University of Virginia Medical Center, Charlottesville, Virginia.
authors.forename: Jonathon Bryce
authors.initials: JB
authors.lastname: Olenczak
authors.affiliation: Department of Plastic Surgery, University of Virginia Medical Center, Charlottesville, Virginia.
authors.forename: Daniel
authors.initials: D
authors.lastname: Murariu
authors.affiliation: Department of Anesthesia, University of Virginia Medical Center, Charlottesville, Virginia.
authors.forename: Keita
authors.initials: K
authors.lastname: Ikeda
authors.affiliation: Department of Anesthesia, University of Virginia Medical Center, Charlottesville, Virginia.
authors.forename: Robert H
authors.initials: RH
authors.lastname: Thiele
authors.affiliation: Department of Plastic Surgery, University of Virginia Medical Center, Charlottesville, Virginia.
authors.forename: Chris A
authors.initials: CA
authors.lastname: Campbell
mesh_terms: D000293:Adolescent; D000328:Adult; D001158:Arteries; D001794:Blood Pressure; D003576:Electron Transport Complex IV / Q000378:metabolism*; D005542:Forearm / Q000098:blood supply* / Q000502:physiology; D064368:Healthy Volunteers; D006454:Hemoglobins / Q000378:metabolism*; D006801:Humans; D007511:Ischemia / Q000473:pathology; D008991:Monitoring, Physiologic / Q000379:methods*; D018482:Muscle, Skeletal / Q000378:metabolism*; D010100:Oxygen / Q000097:blood; D010101:Oxygen Consumption / Q000502:physiology; D019265:Spectroscopy, Near-Infrared / Q000379:methods*; D055815:Young Adult
chemical_list: D006454:Hemoglobins; C100003:deoxyhemoglobin; D003576:Electron Transport Complex IV; D010100:Oxygen