scholarly journals Cerebral and Skeletal Muscle Tissue Oxygenation during Exercise in Children with Sickle Cell Anemia

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 2280-2280
Author(s):  
Christina M Barriteau ◽  
Abraham Chiu ◽  
Mark Rodeghier ◽  
Robert I Liem
Keyword(s):  
Skeletal Muscle ◽  
Oxygen Saturation ◽  
Exercise Testing ◽  
Sickle Cell Anemia ◽  
Tissue Oxygenation ◽  
Vastus Lateralis ◽  
Work Load ◽  
Tissue Oxygen Saturation ◽  
Tissue Oxygen ◽  
Warm Up

Introduction: Sickle cell anemia (SCA) causes impaired tissue oxygenation. Children with SCA have lower peak fitness levels compared to controls. The contribution of alterations in skeletal muscle and cerebral tissue oxygenation to exercise limitation in SCA remains unclear. Near infrared spectroscopy (NIRS) is a validated, non-invasive method to measure tissue oxygen saturation. We hypothesize that compared to controls, children with SCA will exhibit greater reductions in regional tissue oxygen saturation (StO2) measured in the quadriceps (vastus lateralis) and pre frontal cortex (PFC) across all workloads during maximal cardiopulmonary exercise testing (CPET). Methods: We used the CASMED ELITE NIRS tissue oximeter to measure tissue oxygen saturation in the PFC and vastus lateralis (VL) muscle during all phases of maximal CPET, including warm up, active exercise and recovery, in 17 subjects with SCA (mean age 13.5 years) and 13 controls (mean age 15.2 years). Maximal CPET was conducted by cycle ergometry using a standard ramp protocol until volitional exhaustion was reached by all participants. Peak oxygen consumption (VO2) was measured from breath-by breath gas exchange data collected during CPET. Results: All subjects and controls completed maximal CPET without adverse events. Peak VO2 was not statistically different in subjects with SCA versus controls (25.3±4.7 vs 29.5±8.9 mL/kg/min, p=0.22). Compared to controls, subjects with SCA had significantly lower PFC StO2 at all time points during exercise, including warm up, 20%, 40%, 60%, 80% and 100% of peak work load (p<0.01) (Figure 1a). Subjects with SCA demonstrated a significant decrease in PFC StO2 from warm up to 80% peak work load (-3.0±2.9% , p=0.002) and from warm up to 100% peak work load (-5.4±3.4 %, p<0.001) (Figure 1b). In contrast, controls did not demonstrate significant decreases in PFC StO2 from warm up to any point during exercise testing. VL StO2 did not significantly differ between subjects and controls during exercise (p=0.149, Figure 1c). Subjects with SCA demonstrated a significant increase in VL StO2 from warm up to 0% (+3.2±2.8%, p<0.001) and 20% peak work load (+2.3±2.5%, p=0.002) and a significant decrease in StO2 from warm up to 60% (-4.8±4.6%, p<0.001), 80% (-8.6±5.9%, p<0.001) and 100% peak work load (-10.5±6.3%, p<0.001) (Figure 1d). Controls had significant increase in VL StO2 from warm up to 0% peak work load (+4.3±4.0%, p=0.02) and a significant decrease only at 80% (-6.5±6.3%, p=0.003). Differences in PFC and VL StO2 between subjects and controls were also examined at the highest VO2 achieved by all participants. At a VO2 of 17.6 mL/kg/min, PFC StO2 was significantly lower in subjects with SCA versus controls (69.2±6.6 vs 79.5±5.3%, p<0.001). There was a trend toward lower VL StO2 in subjects versus controls (67.7±9.0 vs 73.2±7.9%, p=0.09). Conclusion: Unlike VL tissue oxygenation, PFC tissue oxygenation is relatively well preserved in subjects with SCA and controls during maximal CPET. However, compared to controls, subjects with SCA have lower PFC tissue oxygenation at warm up and during exercise as well as demonstrate significantly greater decreases in PFC tissue oxygenation during later stages of exercise. In contrast, VL tissue oxygenation is similar at warm up and during exercise for subjects and controls. VL tissue oxygenation increases during initial stages of exercise in a similar fashion in subjects with SCA and controls but subsequent decreases from warm up are greater in subjects with SCA during later stages of exercise. Future studies may further elucidate how SCA contributes to these observed differences in regional tissue oxygenation during exercise and their potential impact on exercise safety and fitness in this population. Disclosures No relevant conflicts of interest to declare.

Tissue Oxygenation Monitoring as a Guide for Trauma Resuscitation

2016 ◽  
Vol 36 (3) ◽  
pp. 12-70 ◽  
Author(s):  
Cathy Mitchell
Keyword(s):  
Oxygen Saturation ◽  
Tissue Oxygenation ◽  
Central Venous Oxygen Saturation ◽  
Multiple Organ ◽  
Tissue Oxygen Saturation ◽  
Multiple Organ Dysfunction ◽  
Tissue Oxygen ◽  
Trauma Resuscitation ◽  
Central Venous ◽  
Venous Oxygen Saturation

Hypoperfusion is the most common event preceding the onset of multiple organ dysfunction syndrome during trauma resuscitation. Detecting subtle changes in perfusion is crucial to ensure adequate tissue oxygenation and perfusion. Traditional methods of detecting physiological changes include measurements of blood pressure, heart rate, urine output, serum levels of lactate, mixed venous oxygen saturation, and central venous oxygen saturation. Continuous noninvasive monitoring of tissue oxygen saturation in muscle has the potential to indicate severity of shock, detect occult hypoperfusion, guide resuscitation, and be predictive of the need for interventions to prevent multiple organ dysfunction syndrome. Tissue oxygen saturation is being used in emergency departments, trauma rooms, operating rooms, and emergency medical services. Tissue oxygen saturation technology is just as effective as mixed venous oxygen saturation, central venous oxygen saturation, serum lactate, and Stewart approach with strong ion gap, yet tissue oxygen saturation assessment is also a direct, noninvasive microcirculatory measurement of oxygen saturation.

scholarly journals In Vivo Assessment of Hypoxia Levels in Pancreatic Tumors Using a Dual-Modality Ultrasound/Photoacoustic Imaging System

Micromachines ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 668
Author(s):  
Yuhling Wang ◽  
De-Fu Jhang ◽  
Chia-Hua Tsai ◽  
Nai-Jung Chiang ◽  
Chia-Hui Tsao ◽  
...  
Keyword(s):  
Tumor Growth ◽  
Oxygen Saturation ◽  
Pancreatic Tumor ◽  
Tissue Oxygenation ◽  
Imaging System ◽  
Tissue Oxygen Saturation ◽  
Functional Information ◽  
Tissue Oxygen ◽  
Dual Modality

Noninvasive anatomical and functional imaging has become an essential tool to evaluate tissue oxygen saturation dynamics in preclinical or clinical studies of hypoxia. Our dual-wavelength technique for photoacoustic (PA) imaging based on the differential absorbance spectrum of oxyhemoglobin (oxy-Hb) and deoxyhemoglobin (deoxy-Hb) can quantify tissue oxygen saturation using the intrinsic contrast property. PA imaging of tissue oxygen saturation can be used to monitor tumor-related hypoxia, which is a particularly relevant functional parameter of the tumor microenvironment that has a strong influence on tumor aggressiveness. The simultaneous acquisition of anatomical and functional information using dual-modality ultrasound (US) and PA imaging technology enhances the preclinical applicability of the method. Here, the developed dual-modality US/PA system was used to measure relative tissue oxygenation using the dual-wavelength technique. Tissue oxygen saturation was quantified in a pancreatic tumor mouse model. The differences in tissue oxygenation were detected by comparing pancreatic samples from normal and tumor-bearing mice at various time points after implantation. The use of an in vivo pancreatic tumor model revealed changes in hypoxia at various stages of tumor growth. The US/PA imaging data positively correlated with the results of immunohistochemical staining for hypoxia. Thus, our dual-modality US/PA imaging system can be used to reliably assess and monitor hypoxia in pancreatic tumor mouse models. These findings enable the use of a combination of US and PA imaging to acquire anatomical and functional information on tumor growth and to evaluate treatment responses in longitudinal preclinical studies.

scholarly journals Altered Oxygenation, Vascular and Ischemic Pain Responses in Adults with Sickle Cell Anemia

Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 3399-3399
Author(s):  
Nathan S Fishman ◽  
Joseph Kim ◽  
Daniel Lichy ◽  
Kathleen Vaughan ◽  
Stephen Yoon ◽  
...  
Keyword(s):  
Blood Flow ◽  
Steady State ◽  
Oxygen Saturation ◽  
Sickle Cell ◽  
Sickle Cell Anemia ◽  
Pain Tolerance ◽  
Tissue Oxygen Saturation ◽  
Ischemic Pain ◽  
Tissue Oxygen ◽  
Pain Test

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.

scholarly journals Association of Intraoperative Cerebral and Somatic Tissue Oxygen Saturation with Postoperative Cognitive Dysfunction After Spine Open Surgery in Patients with Hypertension: An Observational Study

2021 ◽  
Author(s):  
Fei Guo ◽  
Shuaiying Jia ◽  
Qiyan Wang ◽  
Qinyu Liu ◽  
Mingquan Hu ◽  
...  
Keyword(s):  
Observational Study ◽  
Oxygen Saturation ◽  
Cognitive Dysfunction ◽  
Open Surgery ◽  
Tissue Oxygenation ◽  
Cerebral Oxygenation ◽  
Postoperative Cognitive Dysfunction ◽  
Somatic Tissue ◽  
Tissue Oxygen Saturation ◽  
Tissue Oxygen

Abstract Background: Intraoperative cerebral desaturations have been associated with worse neurological outcomes after supine surgery. However, it is not clear whether intraoperative somatic tissue oxygenation is more associated with postoperative cognitive dysfunction (POCD) than cerebral oxygenation in patients with hypertension after prone spine surgery.Methods: Patients with hypertension scheduled for spine open surgery were included from 2020 to 2021 in a single-center, prospective, observational study. Baseline both cerebral and somatic tissue oxygen saturation were measured in operating room before surgery. Cerebral and somatic tissue oxygen saturations were monitored continuously throughout surgery. The presence of POCD was assessed using the Mini-Mental Status Examination (MMSE). Association with POCD was evaluated with unadjusted analyses and multivariable logistic regression.Results: One hundred and one of 112 patients were included, and 28 (27.8%) developed POCD. None of the investigated SctO2 variables was predictive of POCD. On the contrary, the patients with POCD had a higher decrease in intraoperative absolute SstO2 decrease and relative SstO2 decrease compared with the patients without POCD (4.9%±3.8% vs. 3.6%±2.6%, P=0.037; 7.4%±5.6% vs. 5.3%±3.8%, P=0.036; respectively). Finally, three SstO2 parameters respectively were associated with POCD, including a higher absolute SstO2 decrease (OR, 1.223; 95%CI, 1.031-1.451; P=0.021), a higher absolute SstO2 decrease (OR, 1.138; 95%CI, 1.011-1.281; P=0.032) and falling below 90% of baseline SstO2 (OR, 11.388; 95%CI, 2.367-54.785; P=0.002), independent of ASA III, preoperative platelet and postoperative sepsis. Conclusions: Twenty-eight (27.8%) of 101patients developed POCD. Somatic tissue oxygenation has a stronger association with POCD than cerebral tissue oxygenation after spine open surgery in patients with hypertension.Clinical trial registration: ChiCTR1900028392. Registered 20 December 2019.

scholarly journals Oxygen Tissue Saturation Is Lower in Nonsurvivors than in Survivors after Early Resuscitation of Septic Shock

2009 ◽  
Vol 111 (2) ◽  
pp. 366-371 ◽  
Author(s):  
Marc Leone ◽  
Sami Blidi ◽  
François Antonini ◽  
Bertrand Meyssignac ◽  
Sébastien Bordon ◽  
...  
Keyword(s):  
Septic Shock ◽  
Oxygen Saturation ◽  
Tissue Oxygenation ◽  
Microvascular Dysfunction ◽  
Tissue Oxygen Saturation ◽  
Tissue Oxygen ◽  
Goal Directed Therapy ◽  
Early Goal Directed Therapy ◽  
Hemodynamic Variables ◽  
Central Venous Saturation

Background Growing evidence suggests that the microvascular dysfunction is the key element of the pathogenesis of septic shock. This study's purpose was to explore whether the outcome of septic shock patients after early resuscitation using early goal-directed therapy is related to their muscle tissue oxygenation. Methods Tissue oxygen saturation (Sto2) was monitored in septic shock patients using a tissue spectrometer (InSpectra Model 325; Hutchinson Technology, Hutchinson, MN). For the purpose of this retrospective study, the Sto2 values were collected at the first measurement done after the macrohemodynamic variables (mean arterial pressure, urine output, central venous saturation in oxygen) were optimized. Results After the hemodynamic variables were corrected, no difference was observed between the nonsurvivors and survivors, with the exception of pulse oximetry saturation (94% [92-97%] vs. 97% [94-99%], P = 0.04). The Sto2 values were significantly lower in the nonsurvivors than in the survivors (73% [68-82%] vs. 84% [81-90%], P = 0.02). No correlations were found between the Sto2 and Spo2 (P = 0.7). Conclusions In septic shock patients, tissue oxygen saturation below 78% is associated with increased mortality at day 28. Further investigations are required to determine whether the correction of an impaired level of tissue oxygen saturation may improve the outcome of these patients.

scholarly journals Quantifying dermal microcirculatory changes of neuropathic and neuroischemic diabetic foot ulcers using spatial frequency domain imaging: a shade of things to come?

2020 ◽  
Vol 8 (2) ◽  
pp. e001815
Author(s):  
Grant A Murphy ◽  
Rajinder P Singh-Moon ◽  
Amaan Mazhar ◽  
David J Cuccia ◽  
Vincent L Rowe ◽  
...  
Keyword(s):  
Diabetes Mellitus ◽  
Spatial Frequency ◽  
Oxygen Saturation ◽  
Diabetic Foot ◽  
Clinical Course ◽  
Tissue Oxygen Saturation ◽  
Tissue Oxygen ◽  
Spatial Frequency Domain Imaging ◽  
Patients With Diabetes ◽  
Spatial Frequency Domain

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.

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