scholarly journals Assessment of human gingival inflammation based on measurements of tissue oxygen saturation and local blood flow

Author(s):  
Takafumi Suto ◽  
Motohide Ikawa ◽  
Satoru Yamada
2017 ◽  
Vol 12 (3) ◽  
pp. 139-145 ◽  
Author(s):  
Hiroyuki Maeda, MD, PhD ◽  
Hideaki Iwase, PhD ◽  
Akio Kanda, MD, PhD ◽  
Itaru Morohashi, MD, PhD ◽  
Kazuo Kaneko, MD, PhD ◽  
...  

Background: After an emergency or disaster, subsequent trauma can cause severe bleeding and this can often prove fatal, so promptly stopping that bleeding is crucial to preventing avoidable trauma deaths. A tourniquet is often used to restrict blood flow to an extremity. In operation and hospital, the tourniquet systems currently in use are pneumatically actuated by an air compressor, so they must have a steady power supply. These devices have several drawbacks: they vibrate and are noisy since they are pneumatically actuated and they are far from portable since they are large and heavy.Introduction: Presumably, the drawbacks of pneumatic tourniquets could be overcome by developing a small, lightweight, vibration-free, quiet, and battery- powered tourniquet system. The current study built a small, vibration-free electrohydrodynamic (EHD) pump and then used that pump to restrict blood flow to the leg of rats in an experiment. This study explored the optimal conditions for effective restriction of blood flow by assessing biochemical and musculoskeletal complications following the restriction of blood flow, and this study also examined whether or not an EHD pump could be used to actuate a tourniquet system.Methods: A tourniquet cuff (width 12 mm × length 150 mm, material: polyolefin) was placed on the thigh of Wistar rats and pressure was applied for 2 hours by a device that uses EHD phenomena to generate pressure (an EHD pump). Animals were divided into four groups based on how much compressive pressure was applied with a tourniquet: 40 kPa (300 mm Hg, n = 13),  30 kPa (225 mm Hg, n = 12), 20 kPa (150 mm Hg, n = 15), or 0 kPa (controls, n = 25). Tissue oxygen saturation (regional oxygen saturation, denoted here as rSO2) was measured to assess the restriction of blood flow. To assess behavior once blood flow resumed, animal activity was monitored for third day and the amount of movement was counted with digital counters. Body weight was measured before and after the behavioral experiment, and changes in body weight were determined. Blood was sampled after a behavioral experiment and biochemically assessed and creatine kinase (CK) levels were measured.Results: Tissue oxygen saturation decreased significantly in each group. When a tourniquet was applied at a pressure of 30 kPa or more, tissue oxygen saturation decreased significantly. The amount of movement (the count) over third day decreased more when a tourniquet was applied at a higher pressure. The control group resumed the same amount of movement per day second after blood flow resumed. Animals to which a tourniquet was applied at a pressure of 20 or 30 kPa resumed the same amount of movement third day after blood flow resumed. In contrast, animals to which a tourniquet was applied at a pressure of 40 kPa did not resume the same amount of movement third day after blood flow resumed. After the behavioral experiment, animals to which a tourniquet was applied at a pressure of 40 kPa had a significantly lower body weight in comparison to the control group. After the behavioral experiment, animals to which a tourniquet was applied at a pressure of 40 kPa had significantly elevated CK levels in comparison to the control group.Discussion and Conclusion: A relationship between blood flow restriction pressure and tissue oxygen saturation was noted. rSO2 measurement can be used to assess the restriction of blood flow during surgery. On the basis of the decrease in rSO2, blood flow was effectively restricted at a pressure of 30 kPa or more. When, however, blood flow was restricted at a pressure of 40 kPa, weight loss and decreased movement were noted and CK levels increased after the behavioral experiment. Thus, complications had presumably developed due to damage to muscle tissue. These findings indicate that blood flow was effectively restricted in this experiment and they also indicate the existence of an optimal blood flow restriction pressure that does not cause musculoskeletal complications. The pressure in question was around 30 kPa. The tourniquet system that was developed here is actuated with an EHD pump that is still in the trial stages. That said, its pressure can readily be controlled and this pump could be used in a tourniquet system since it is quiet, vibration-free, and small. The pressure of this pump can be finely adjusted to prevent musculoskeletal complications.


2014 ◽  
Vol 92 (2) ◽  
pp. 149-154 ◽  
Author(s):  
Jan M. Warnecke ◽  
Thomas Wendt ◽  
Stefan Winkler ◽  
Matthias Schak ◽  
Thorsten Schiffer ◽  
...  

Topical agents like nonivamide and nicoboxil induce hyperaemisation and increase cutaneous blood flow and temperature. This study aimed to determine the effects of a nonivamide–nicoboxil cream on haemodynamics in the skin and calf muscle, via optical spectroscopy, discriminating between the changes for skin and muscle. Optical spectroscopy was applied in the visible (VIS) and near-infrared (NIR) wavelength range. The study determined the effect of the cream on changes in oxygenated (ΔoxyHb) and deoxygenated (ΔdeoxyHb) haemoglobin in skin and muscle, as well as on tissue oxygen saturation (SO2) in the skin of 14 healthy subjects. The left and right calves of the subjects were either treated with nonivamide–nicoboxil cream or were sham-administered. NIR spectroscopy allows noninvasive in-vivo examination of the oxygenation of human skeletal muscle. Topical administration of the nonivamide–nicoboxil cream significantly increased the concentration of oxygenated haemoglobin and tissue oxygen saturation in the skin, as well as the concentration of oxygenated haemoglobin in the muscle of the treated legs after 15 min, but with stronger and faster effects in the skin. The topical application of the nonivamide–nicoboxil cream increased blood flow in (smaller vessels of) the skin and muscle tissues.


Circulation ◽  
2014 ◽  
Vol 130 (suppl_2) ◽  
Author(s):  
Tetsuo Hatanaka ◽  
Hiroshi Kaneko ◽  
Aki Nagase ◽  
Seishiro Marukawa

Introduction: Cerebral tissue oxygen saturation measured with transcranial near-infrared spectroscopy (NIRS) has been reported to predict neurological outcome of cardiac arrest patients. Because NIRS values are confounded by extracranial tissues, there can be considerable inter-device variation in the measured values. We compared hyperventilation-induced changes in NIRS values measured with 2 commercially available devices in healthy volunteers. Methods: After obtaining an approval from the ethics committee at Iseikai hospital and written informed consents, 29 healthy volunteers joined the study. Probes of NIRO™ 200NX (Hamamatsu Photonics, Japan) and INVOS™ 5100C (Covidien, USA) were applied respectively on the right and left side of the volunteers’ forehead. After obtaining the baseline values, the volunteers were asked to hyperventilate for 40 seconds attempting to reduce the end-tidal CO 2 by ~20 mmHg. Measurements were repeated, after 20 minutes of resting interval, with the probes applied on the contralateral sides. Hyperventilation-induced response of the NIRS value was categorized as “correct” when the average value over the 5 second period toward the end of the hyperventilation decreased by >15% the baseline or “erroneous” otherwise. Results: The mean (± SD) end-tidal CO 2 decreased from the baseline value of 36 ± 5.1 mmHg to 15.2 ± 4.4 mmHg during hyperventilation. Out of 58 measurements with each of the devices, NIRO values were “correct” in 54 (93.1%) measurements, whereas INVOS values were “correct” in 32 (52.2%) measurements. NIRO presented “erroneous” values on both sides of the forehead in no volunteers whereas INVOS presented “erroneous” values in 7 (35%) of 29 volunteers. Discussion: Hyperventilation consistently decreases cerebral blood flow in healthy subjects. Thus, the results of the present study suggest that NIRS devices may fail to reflect correct changes in cerebral tissue oxygen saturation in ~7% of measurements with NIRO and in ~48% with INVOS. The bilateral “erroneous” measurements with INVOS in 7 (35%) volunteers may suggest that INVOS is subject to confounding by extracranial tissues. A potential source of confounding may include the scalp where blood flow increases during hyperventilation.


Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 3399-3399
Author(s):  
Nathan S Fishman ◽  
Joseph Kim ◽  
Daniel Lichy ◽  
Kathleen Vaughan ◽  
Stephen Yoon ◽  
...  

Abstract The clinical hallmark of sickle cell anemia is the vaso-occlusive pain crisis. Although the exact cause for severe vaso-occlusive painful events is unknown, sickle cell microvasculature occlusion is thought to be the proximate cause producing tissue hypoxia, reperfusion injury and acute pain. Endothelial dysfunction is a prominent characteristic of sickle cell anemia, and it is unclear to what extent this abnormal vascular response contributes to vaso-occlusion and pain. We sought to evaluate the effects of hypoxia on sickle cell pain by performing a forearm ischemic pain test as a potential in vivo model for vaso-occlusion. We hypothesized that sickle cell anemia patients would tolerate a shorter period of ischemia before reaching pain tolerance. We further hypothesized that sickle patients would show more hypoxia and increased vasodilation. Thirty adults with sickle cell anemia were recruited and matched by age and sex to 30 normal volunteers. We first performed a timed ischemic pain test with brachial artery occlusion until subjects first reported pain (pain threshold) and until maximum pain tolerated (pain tolerance). Sickle cell subjects first reported pain at 411 vs. 589 s for normal volunteers (mean, p=0.07). Occlusion time to pain tolerance was significantly shorter for sickle cell patients (637 vs. 918 s, mean, p=0.004). Despite this difference, both groups reported nearly identical pain scores at threshold and tolerance. Stepwise linear regression for all subjects against 8 variables likely to influence pain showed sickle status (p=0.002) and gender (p=0.0008) were independently associated with time to tolerance, supporting our initial hypothesis. Testing with continuous physiological monitoring was next repeated in sub-groups of 7 sickle cell and 9 normal subjects in an effort to understand the association between ischemia and pain progression. Before, during, and after brachial artery occlusion, oxygenated/deoxygenated hemoglobin concentration and tissue oxygen saturation were continuously monitored with near-infrared spectroscopy at the thenar eminence. We also recorded cutaneous blood flow with a Laser Speckle Contrast Imager (FLPI-2) in the volar aspect of forearm and continuous blood pressure and pulse in the contralateral arm. Monitoring was performed during steady state prior to occlusion (15 min), during occlusion until pain tolerance, and during recovery (20 min). At steady state, sickle cell subjects had higher median heart rate (68 vs. 62 bpm, p=0.05) and cutaneous blood flow (81.8 vs. 46.8 a.u., p<0.0001). They also had lower median oxygenated hemoglobin (51.3 vs. 68 μM, p<0.0001), tissue oxygen saturation (62 vs. 68%, p<0.0001) and blood pressure (110/75 vs. 126/80, p<0.0001). During occlusion, the absolute decline in blood flow, calculated as a difference between median steady state flow and flow at 2 min of occlusion, was greater with sickle group (40.8 vs. 20.63 a.u., p=0.05). However, sickle cell oxygenated hemoglobin decreased at a slower rate (-0.12 vs. -0.15, median, p<0.0001). As before, time to pain tolerance was shorter with sickle cell (566 vs. 1460 sec., median, p=0.009). Surprisingly, sickle subjects had higher median tissue oxygen saturation (28.9 vs. 25.7%, p=0.005) and oxygenated hemoglobin (22.9 vs. 20.0 μM, p=0.006) at pain tolerance, but blood flow was not different. Consistent with this pattern, recovery of oxygenated hemoglobin occurred at a slower rate in the sickle group (0.61 vs. 0.84, median, p<0.0001). Sickle subjects had a brief hyperemic recovery period during which they returned to lower baseline levels of tissue oxygen saturation and oxygenated hemoglobin, and the duration of this hyperemic recovery was the same in normal volunteers. Overall, sickle cell subjects have significantly lower steady state tissue oxygenation, but they are less tolerant of hypoxia and develop pain at higher oxygenated hemoglobin levels during ischemia. Despite higher oxygenated hemoglobin during ischemia, sickle cell subjects have a significantly higher absolute decline in blood flow during occlusion, suggesting an altered hypoxic response compared to controls. This might suggest a hypersensitive hypoxic pain response, possibly due to the presence of chronic pain, and altered oxygen sensing. The ischemic pain test is a potential in vivo model for early stage trials of drugs that alter either acute pain transmission or oxygen delivery to tissues. Disclosures No relevant conflicts of interest to declare.


2001 ◽  
Vol 23 (8) ◽  
pp. 875-880 ◽  
Author(s):  
Hiroyuki Nakase ◽  
Song Zhenquan ◽  
Akihira Kotani ◽  
Mitsutoshi Nakamura ◽  
Toshisuke Sakaki

2003 ◽  
Vol 285 (3) ◽  
pp. H1183-H1189 ◽  
Author(s):  
Karel J. Zuzak ◽  
Mark T. Gladwin ◽  
Richard O. Cannon ◽  
Ira W. Levin

Sickle cell disease is characterized by microvascular occlusion and hemolytic anemia, factors that impair tissue oxygen delivery. We use visible reflectance hyperspectral imaging to quantitate skin tissue hemoglobin oxygen saturation (HbO2) and to determine whether changes in blood flow during nitric oxide (NO) stimulation or gas administration (therapies proposed for this disease) improve skin tissue oxygen saturation in five patients with sickle cell disease. Compared with six healthy African-American subjects, sickle cell patients exhibited higher forearm blood flows (7.4 ± 1.8 vs. 3.2 ± 0.4 ml·min–1·100 ml tissue–1, P = 0.037) but significantly reduced percentages of skin HbO2 (61.0 ± 0.2 vs. 77.5 ± 0.2%, P < 0.001). Administration of acetylcholine to patients increased blood flow by 15.1 ± 3.8 ml·min–1·100 ml tissue–1 and the percentage of skin HbO2 by 4.1 ± 0.3% ( P = 0.02, P < 0.001, respectively, from baseline values). Sodium nitroprusside, a direct NO donor, increased blood flow by 3.9 ± 1.1 ml/min and the percentage of skin HbO2 by 2.9 ± 0.3% ( P = 0.02, P < 0.001, respectively). NO inhalation had no effect on forearm blood flow, yet increased the percentage of skin HbO2 by 2.3 ± 0.3% ( P < 0.001). Percentages of skin HbO2 were exponentially related to blood flow ( R = 0.97, P < 0.001), indicating a limit to skin tissue oxygen saturation at high blood flows. Thus, for acetylcholine infusion leading to blood flows sevenfold greater than those of healthy resting African-American subjects, patients still exhibited lower percentages of skin HbO2 (65.2 ± 0.2 vs. 77.5 ± 0.2%, P < 0.001). Visible reflectance hyperspectral imaging demonstrates that either the stimulation or the administration of NO pharmacologically or by gas inhalation improves, but does not normalize, skin tissue oxygen saturation in patients with sickle cell disease.


2020 ◽  
Vol 8 (2) ◽  
pp. e001815
Author(s):  
Grant A Murphy ◽  
Rajinder P Singh-Moon ◽  
Amaan Mazhar ◽  
David J Cuccia ◽  
Vincent L Rowe ◽  
...  

IntroductionThe use of non-invasive vascular and perfusion diagnostics are an important part of assessing lower extremity ulceration and amputation risk in patients with diabetes mellitus. Methods for detecting impaired microvascular vasodilatory function in patients with diabetes may have the potential to identify sites at risk of ulceration prior to clinically identifiable signs. Spatial frequency domain imaging (SFDI) uses patterned near-infrared and visible light spectroscopy to determine tissue oxygen saturation and hemoglobin distribution within the superficial and deep dermis, showing distinct microcirculatory and oxygenation changes that occur prior to neuropathic and neuroischemic ulceration.Research designs and methods35 patients with diabetes mellitus and a history of diabetic foot ulceration were recruited for monthly imaging with SFDI. Two patients who ulcerated during the year-long longitudinal study were selected for presentation of their clinical course alongside the dermal microcirculation biomarkers from SFDI.ResultsPatient 1 developed a neuropathic ulcer portended by a focal increase in tissue oxygen saturation and decrease in superficial papillary hemoglobin concentration 3 months prior. Patient 2 developed bilateral neuroischemic ulcers showing decreased tissue oxygen saturation and increased superficial papillary and deep dermal reticular hemoglobin concentrations.ConclusionsWounds of different etiology show unique dermal microcirculatory changes prior to gross ulceration. Before predictive models can be developed from SFDI, biomarker data must be correlated with the clinical course of patients who ulcerate while being followed longitudinally.Trial registration numberNCT03341559.


Sign in / Sign up

Export Citation Format

Share Document