Blood Oxygenation Parameters Research Articles

Real-time estimation of blood oxygenation parameters from human foot sole during leg elevation: A preliminary study with diffuse reflectance spectroscopy

This study investigated the applicability of diffuse reflectance spectroscopy (DRS) for real-time and non-invasive measurement of blood oxygenation parameters (BOPs) such as reduced hemoglobin (RHb), oxyhemoglobin (HbO2), and oxygen saturation (SO2) from human foot sole during leg elevation. Seventeen (17) healthy male subjects aged between 21 to 39 years were included in this study. Diffuse reflectance spectra were recorded from measurement sites namely the 5th metatarsal, ball of great joint, calcaneum, and great toe of the human foot sole w.r.t. leg elevation angles such as 00, 150, 300, 450, and 600, respectively. The localized BOPs were derived from the recorded spectra. In addition, blood hemodynamic parameters (BHPs) such as heart rate (HR), SO2, perfusion index (PI), systolic blood pressure (SBP), and diastolic blood pressure (DBP) were also measured for each elevating angle. To study and assess the changes in BOPs and BHPs w.r.t. leg elevation, a One-way ANOVA test followed by a Tukey HSD post-hoc test was performed. We observed a statistically significant increase in RHb (p < 0.001) and a decrease in HbO2 (p < 0.001) after 45° of leg elevation, however, there was no statistically significant difference in SO2 (p = 0.74) and HR (p = 0.84) for each measurement site w.r.t. leg elevation, respectively. Furthermore, PI (p < 0.01), ankle SBP (p < 0.001) and DBP (p < 0.001) were decreased w.r.t. leg elevation. The obtained results are in agreement with the literature. The preliminary results suggest that DRS has the potential for real-time estimation of BOPs from the local sites of healthy human foot soles during leg elevation. Thus, it opens the possibility of DRS to monitor and evaluate the diagnosis and treatment of ischemia and edema during leg elevation of patients through BOPs measurement.

The Mito-Hormetic Mechanisms of Ozone in the Clearance of SARS-CoV2 and in the COVID-19 Therapy.

An increasing body of evidence in the literature is reporting the feasibility of using medical ozone as a possible alternative and adjuvant treatment for COVID-19 patients, significantly reducing hospitalization time, pro-inflammatory indicators, and coagulation markers and improving blood oxygenation parameters. In addition to the well-described ability of medical ozone in counteracting oxidative stress through the upregulation of the main anti-oxidant and scavenging enzymes, oxygen–ozone (O2–O3) therapy has also proved effective in reducing chronic inflammation and the occurrence of immune thrombosis, two key players involved in COVID-19 exacerbation and severity. As chronic inflammation and oxidative stress are also reported to be among the main drivers of the long sequelae of SARS-CoV2 infection, a rising number of studies is investigating the potential of O2–O3 therapy to reduce and/or prevent the wide range of post-COVID (or PASC)-related disorders. This narrative review aims to describe the molecular mechanisms through which medical ozone acts, to summarize the clinical evidence on the use of O2–O3 therapy as an alternative and adjuvant COVID-19 treatment, and to discuss the emerging potential of this approach in the context of PASC symptoms, thus offering new insights into effective and safe nonantiviral therapies for the fighting of this devastating pandemic.

Diffuse reflectance-based spectroscopic technique for real-time estimation of localized blood oxygenation parameters from human fingertips: a preliminary study

Non-invasive and real-time measurement of localized blood oxygenation parameters such as reduced hemoglobin, oxyhemoglobin, and oxygen saturation are regularly required by emergency &amp; rescue teams as well as by intensive care units (ICUs).

Oxygen Sparing Effect of Bacteriotherapy in COVID-19.

Background: We previously reported that severe COVID-19 patients had higher chances of survival and a reduced risk of developing respiratory failure when administered with the probiotic formulation SLAB51. This study aimed to investigate further bacteriotherapy mechanisms and how early they are activated. Methods: We performed an analysis on the blood oxygenation parameters collected in sixty-nine severe COVID-19 patients requiring non-invasive oxygen therapy and presenting a CT lung involvement ≥50%. Twenty-nine patients received low-molecular-weight heparin, azithromycin and Remdesivir. In addition, forty subjects received SLAB51. Blood gas analyses were performed before the beginning of treatments and at 24 h. Results: The patients receiving only standard therapy needed significantly increased oxygen amounts during the 24 h observation period. Furthermore, they presented lower blood levels of pO2, O2Hb and SaO2 than the group also supplemented with oral bacteriotherapy. In vitro data suggest that SLAB51 can reduce nitric oxide synthesis in intestinal cells. Conclusions: SARS-CoV-2 infected patients may present lesions in the lungs compromising their gas exchange capability. The functionality of the organs essential for these patients’ survival depends mainly on the levels of pO2, O2Hb and SaO2. SLAB51 contains enzymes that could reduce oxygen consumption in the intestine, making it available for the other organs.

CARDIOVASCULAR CONTROL RESPONSES IN HIGH INTENSITY EXERCISE STRESS TESTS

ABSTRACT Introduction: High intensity exercise is an important factor to achieve the best exercise effect, and is closely related to the patient's safety and rehabilitation. Objective: To investigate the effects of high intensity exercise on cardiovascular response and substance and energy metabolism. Methods: 50 male students at a university were selected. The average age of the subjects was 23 years old. Process of the experiment: Before the experiment, each subject took routine warm-up activities first, then put on the experimental equipment and began to run 100 meters. At the same time, the subjects’ heart rate, blood oxygen parameters and exercise time were recorded. After passing the finish line, a period of heart rate recording and blood oxygen parameters were continued. Results: Anaerobic metabolism was the main activity in the 100m race. The first 7s after the start of the race, there is a non-lactic acid process without oxygen metabolism, and the muscle oxygen saturation curve presents little change. Conclusions: High intensity exercise in sports training and physical exercise can lead to reduced heart rate variability. The increased incidence of various arrhythmias should be based on the actual situation of the movement of the object, and a reasonable arrangement of exercise load intensity. Level of evidence II; Therapeutic studies - investigation of treatment results.

Nursing Research on Patients with Hypertensive Intracerebral Hemorrhage Based on Fuzzy Neural Network Related Algorithm Under Postural Adjustment

Objective: To use the multi-mode fuzzy neural network monitoring measures explored in this project to clarify the trends of rSO2, ICP and CPP in patients with neurological HICH after different postures, and to screen the best nursing position for patients after HICH. Provide a basis for development. Methods: A total of 34 HICH patients admitted to the hospital from January 2017 to December 2018 were included in the study. The patient was placed in the supine position with the head position raised by 0°, 15°, 30°, 45°, 0°, and the interval between different body positions was 5 minutes. Each position was kept for 5 minutes, and the monitoring index values were read after stabilization. EGOS-600A near-infrared tissue blood oxygen parameters non-destructive monitor was used for bedside, dynamic and non-invasive real-time monitoring of rSO2; Codman intracranial pressure monitor was used for continuous dynamic monitoring of ICP; all patients were monitored with ICP and HPM-1205A ECG The monitor measures heart rate (HR), non-invasive blood pressure (BP), and pulse oximetry (SPO2). Results: When the bed angle of the patient was raised by 0°, 15°, 30° and 45°, the ICP value showed a decreasing trend with the elevation of the patient's bed angle. The ICP values were compared at various angles, and the difference was significant. Significance (P = 0.000); MAP value comparison, no significant difference (P = 0.074); CPP value showed an increasing trend with the elevation of the patient's bedside angle, the difference was significant, statistically significant (P = 0.000). There was no significant difference in HR values (P = 0.470). There was no significant difference in SPO2 values (P = 0.780). Conclusion: For patients with HICH with a GCS score of 5 to 12, multi-mode neurological monitoring, supine position elevation of 15°∼30° is a relatively suitable position; HICH patients with NIRS for rSO2 non-invasive monitoring is very Necessary, and should pay more attention to cerebral blood oxygenation changes in patients undergoing medical care after tracheotomy; use multiple modes of monitoring to ensure that patients SaO2, PaO2, MAP, ICP, CPP, and RSO2 are within the normal range. Choosing the most effective and reliable data support for the care and treatment measures that are most beneficial to improve the cerebral ischemia and hypoxia in patients has certain clinical value.

Non-invasive determination of murine placental and foetal functional parameters with multispectral optoacoustic tomography

Despite the importance of placental function in embryonic development, it remains poorly understood and challenging to characterize, primarily due to the lack of non-invasive imaging tools capable of monitoring placental and foetal oxygenation and perfusion parameters during pregnancy. We developed an optoacoustic tomography approach for real-time imaging through entire ~4 cm cross-sections of pregnant mice. Functional changes in both maternal and embryo regions were studied at different gestation days when subjected to an oxygen breathing challenge and perfusion with indocyanine green. Structural phenotyping of the cross-sectional scans highlighted different internal organs, whereas multi-wavelength acquisitions enabled non-invasive label-free spectroscopic assessment of blood-oxygenation parameters in foeto-placental regions, rendering a strong correlation with the amount of oxygen administered. Likewise, the placental function in protecting the embryo from extrinsically administered agents was substantiated. The proposed methodology may potentially further serve as a probing mechanism to appraise embryo development during pregnancy in the clinical setting.

Assessment of the static upright balance index and brain blood oxygen levels as parameters to evaluate pilot workload.

ObjectiveTo investigate the potential for static upright balance function and brain-blood oxygen parameters to evaluate pilot workload.MethodsPhase 1: The NASA Task Load Index (NASA-TLX) was used to compare the workloads of real flights with flight simulator simulated flight tasks in 15 pilots (Cohort 1). Phase 2: To determine the effects of workload, 50 cadets were divided equally into simulated flight task load (experimental) and control groups (Cohort 2). The experimental group underwent 2 h of simulated flight tasks, while the control group rested for 2 h. Their static upright balance function was evaluated using balance index-1 (BI-1), before and after the tasks, with balance system posturography equipment and cerebral blood oxygen parameters monitored with near infrared spectroscopy (NIRS) in real time. Sternberg dual-task and reaction time tests were performed in the experimental and control groups before and after the simulated flight tasks.Results(Phase1) There was a significant correlation between the workload caused by real flight and simulated flight tasks (P<0.01), indicating that NASA-TLX scales were also a tool for measuring workloads of the stimulated flight tasks. (Phase 2) For the simulated flight task experiments, the NASA-TLX total scores were significantly different between the two groups (P<0.001) and (pre-to-post) changes of the BI-1 index were greater in the experimental group than in controls (P<0.001). The cerebral blood oxygen saturation levels (rsO2) (P<0.01) and ΔHb reductions (P<0.05) were significantly higher in the experimental, compared to the control group, during the simulated flight task. In contrast to the control group the error rates (P = 0.002) and accuracy (P<0.001) changed significantly in the experimental group after the simulated flight tasks.ConclusionsThe simulated flight task model could simulate the real flight task load and static balance and NIRS were useful for evaluating pilots’ workload/fatigue.

The efficiency of blood photomodification with therapeutic doses of optical radiation of different wavelengths

Spectra of radiation penetration depth into the blood and skin tissues were calculated for the wavelength range of 405 to 950 nm with the optical properties of biological tissues taken into account. The proportion of radiation that reached the blood in the blood vessel in the case of supravenous irradiation of blood was estimated. Optimal wavelengths that allowed efficient formation of molecular oxygen in the blood due to photodissociation of oxyhemoglobin upon intravenous and supravenous irradiation of blood were determined. Changes in blood oxygenation parameters characteristic of phototherapy, such as the degree of hemoglobin saturation with oxygen, oxyhemoglobin concentration, partial pressure of oxygen, and the concentrations of certain products of metabolism initiated by the photodissociation of oxyhemoglobin, have been demonstrated for optical radiation of different wavelengths. The physical causes of changes in oxygenation characteristics and metabolic product levels induced by photohemotherapy are considered.

Volumetric hand-held optoacoustic angiography as a tool for real-time screening of dense breast.

Existing mammographic screening solutions are generally associated with several major drawbacks, such as exposure to ionizing radiation or insufficient sensitivity in younger populations with radiographically-dense breast. Even when combined with ultrasound or magnetic resonance imaging, X-Ray mammography may still attain unspecific or false positive results. Thus, development of new breast imaging tools represents a timely medical challenge. We report on a new approach to high-resolution functional and anatomical breast angiography using volumetric hand-held optoacoustic tomography, which employs light intensities safe for human use. Experiments in young healthy volunteers with fibroglandular-dominated dense breasts revealed the feasibility of rendering three-dimensional images representing vascular anatomy and functional blood oxygenation parameters at video rate. Sufficient contrast was achieved at depths beyond 2 cm within dense breasts without compromising the real-time imaging performance. The suggested solution may thus find applicability as a standalone or supplemental screening tool for early detection and follow-up of carcinomas in radiographically-dense breasts. Volumetric handheld optoacoustic tomography scanner uses safe pulses of near-infrared light to render three-dimensional images of deep vascular anatomy, blood oxygenation and breast parenchyma at video rate.

THE PARAMETERS OF THE OXYGEN STATUS IN THE ASSESSMENT OF PROGNOSIS OF A HEMODYNAMICALLY SIGNIFICANT PATENT DUCTUS ARTERIOSUS PRETERM NEONATAL INFANTS

Objective: to estimate the significance of capillary blood oxygen parameters for the prognosis of longstanding hemodynamically significant patent ductus arteriosus (HSPDA) in extremely low birthweight (ELBW) neonates. Subjects and methods. On day 8 of their life, two groups of ELBW newborn infants with and without HSPDA were examined for capillary blood рН, рkО2, %SO2с, O2ct, АkDO2, and RIk, as well as mechanical ventilation (MV) parameters (Pip, MAP, and FiO2). Comparison of two independent samples used nonparametric statistical tests: MannWhitney test, Wald Wolfowitz test, and Kolmogorov-Smirnov test. A logistic regression analysis was used to assess the relationship between the examined parameters and the presence or absence of HSPDA. ROC curves were constructed, by choosing the cut-off point, to estimate the predictive power of the model developed using logistic regression. Results. The developed model has high sensitivity and high specificity (84,6 and 97% respectively). The logistic regression equation takes the form: -0.479•О2сt+0.708•Pip-6.823. Conclusion. Capillary blood oxygen parameters proved suitable for predicting the duration of HSPDA functioning. The resultant good predictive power of the model developed for day 8 of life points to the fact that this period is critical from the viewpoint of resolution of respiratory distress syndrome or development of bronchopulmonary dysplasia, which is crucially significant for MV duration and further prediction. HSPDA is one of the most important factors contributing to the development of bronchopulmonary dysplasia in ELBW neonatal infants.

Effects of post-sampling analysis time, type of blood samples and collection tubes on values of blood gas testing.

To investigate effects of post-sampling analysis time, a type of blood samples and collection tubes on blood gas testing. This study included 100 patients at the Clinic for Pulmonary Diseases, Clinical Centre Sarajevo. The partial pressure of oxygen (pO2) and carbon dioxide (pCO2), and the oxygen saturation level of hemoglobin (sO2) were analyzed in the arterial blood samples (ABS) and capillary blood samples (CBS) by a potentiometric method using a blood gas analyzer ABL 555 (Radiometer, Copenhagen, Denmark). Paired measurements of ABS were performed within 15 minutes and after 60 minutes from sampling and compared. The results of CBS obtained within 15 minutes were compared with matching ABS results, as well as the results obtained from CBS within 15 minutes taken into glass and plastic tubes. pO2 and sO2 values were significantly lower after 60 minutes compared to those within 15 minutes in ABS (9.20±1.89 vs. 9.51±1.95 and 91.25±5.03 vs. 92.40±4.5; p<0.01, respectively). Values of pO2 and sO2 in CBS were significantly lower than values obtained in ABS (8.92±2.07 vs. 9.51±1.95 and 91.25±4.86 vs. 92.40±4.50; p<0.01, respectively). Obtained pO2 and sO2 values in CBS in the plastic tubes were higher than those in the glass tubes (8.50±1.98 vs. 7.89±2.0 and 89.66±11.04 vs. 88.23±11.22, p<0.01 respectively). pCO2 blood values were not influenced significantly (p>0.05). The length of post-sampling analysis time, a type of blood samples and collection tubes have significant impact on blood oxygen parameters. Analysis within 15 minutes after blood sampling is considered as appropriate.

Lookup-table-based inverse model for human skin reflectance spectroscopy: two-layered Monte Carlo simulations and experiments

Fiber reflectance spectroscopy is a non-invasive method for diagnosing skin diseases or evaluating aesthetic efficacy, but it is dependent on the inverse model validity. In this work, a lookup-table-based inverse model is developed using two-layered Monte Carlo simulations in order to extract the physiological and optical properties of skin. The melanin volume fraction and blood oxygen parameters are extracted from fiber reflectance spectra of in vivo human skin. The former indicates good coincidence with a commercial skin-melanin probe, and the latter (based on forearm venous occlusion and ischemia, and hot compress experiment) shows that the measurements are in agreement with physiological changes. These results verify the potential of this spectroscopy technique for evaluating the physiological characteristics of human skin.

Functional optoacoustic human angiography with handheld video rate three dimensional scanner

Optoacoustic imaging provides a unique combination of high optical contrast and excellent spatial resolution, making it ideal for simultaneous imaging of tissue anatomy as well as functional and molecular contrast in deep optically opaque tissues. We report on development of a portable clinical system for three-dimensional optoacoustic visualization of deep human tissues at video rate. Studies in human volunteers have demonstrated powerful performance in delivering high resolution volumetric multispectral optoacoustic tomography (vMSOT) images of tissue morphology and function, such as blood oxygenation parameters, in real time. Whilst most imaging modalities currently in clinical use are not able to deliver volumetric data with comparable time resolution, the presented imaging approach holds promise to attain new diagnostic and treatment monitoring value for multiple indications, such as cardiovascular and peripheral vascular disease, disorders related to the lymphatic system, breast lesions, arthritis and inflammation.

Combined Clot Fragmentation and Aspiration in Patients With Acute Pulmonary Embolism*

Massive angiographic pulmonary embolism (PE) with right ventricular dysfunction (RVD) is associated with a high early mortality rate. The therapeutic alternatives for this condition include thrombolysis, surgical embolectomy, or percutaneous mechanical thrombectomy (PMT). We describe our experience using PMT in patients with massive PE and RVD with unsuccessful thrombolysis, increased bleeding risk, or major contraindications for thrombolytic therapy. Clinical, hemodynamic, and angiographic parameters prior to and following PMT were evaluated. Our primary objective was to describe the incidence of in-hospital cardiovascular death, and of major and minor complications. Mid-term outcomes included analysis of occurrence of cardiovascular death, recurrent pulmonary embolism, change of New York Heart Association functional class, and hospital readmission. From July 2004 to May 2007, 69 patients were referred to the cardiac catheterization laboratory with a diagnosis of acute PE, 18 of whom met the criteria for massive PE and are the subject of this study. All patients underwent thrombus fragmentation using a pigtail catheter that was complemented in 13 patients with thrombus aspiration. A percutaneous thrombectomy device (Aspirex; Straub Medical; Wangs, Switzerland) was used in 11 patients. Hemodynamic, angiographic, and blood oxygenation parameters improved after the procedure. A significant increase was observed for systolic systemic BP (74.3+/-7.5 mm Hg vs 89.4+/-11.3 mm Hg, p=0.001) [mean+/-SD], as was a decrease in mean pulmonary artery pressure (37.1+/-8.5 mm Hg vs 32.3+/-10.5 mm Hg , p=0.0001). The in-hospital major complications rate was 11.1%; one patient died from refractory shock, and one patient had intracerebral hemorrhage with minor neurologic sequelae. No cardiovascular deaths or recurrent pulmonary thromboembolism were documented during clinical follow-up (12.3+/-9.4 months). In patients with massive PE, RVD and major contraindications to thrombolytic therapy, increased bleeding risk, failed thrombolysis, or unavailable surgical thrombectomy, PMT appears to be a useful therapeutic alternative.

The association between the proximal extension of the clot and the severity of pulmonary embolism (PE): a proposal for a new radiological score for PE

The aim of the study was to investigate the association between the proximal level of the clot and the severity of pulmonary embolism (PE). The cohort consisted of 99 consecutive patients with PE diagnosed by multi-detector computed tomography. A new score was constructed by calculating the mean value of the largest affected vessel [sub-segmental = 1, segmental = 2, lobar = 3, main pulmonary artery (MPA) = 4] in each lung. A significant association was found between the most proximal level of PE and pulmonary artery obstruction index (PAOI) (P < 0.0001), right ventricular (RV)/left ventricular (LV) ratio (P < 0.0001), and PaO(2) (P = 0.004). No significant association was found between systolic blood pressure and the level of PE. Troponin-T was elevated in none of the sub-segmental, 5% of segmental, 20% of lobar, and in 56% of PEs in the MPA (P = 0.001). Significant association was found between the proposed score and PAOI (P < 0.0001), RV/LV ratio (P < 0.0001), PaO(2) (P < 0.008). Troponin-T was elevated in 10% of level 1, 0% of level 2, 43% level of 3, 66% of level 4 PE (P < 0.0001). Cut-off level score 4 yielded a sensitivity of 84% and a specificity of 74% for the detection of elevated troponin-T. In conclusion, the study indicates that both the most proximal level of PE and the proposed score are related to the severity of PE as determined by blood oxygenation, biochemical and radiological parameters and could therefore be of value for rapid risk stratification of PE. However, the prognostic value of these classifications and their clinical significance needs to be evaluated in properly designed studies.

Blood oxygen parameters in patients with chronic obstructive pulmonary disease. An evaluation of measured and calculated 2,3-diphosphoglycerate concentrations

48 simultaneous arterial and venous blood samples from 15 patients with chronic obstructive pulmonary disease (COPD) were evaluated for calculated p50 and measured and calculated 2,3-diphosphoglycerate (DPG) concentration. 23 samples (48%) demonstrated a leftward shift in the calculated in vivo p50, whereas both measured and calculated DPG showed 5% below and 28% above reference range. Measured DPG was significantly higher than calculated DPG in the leftshifted group, whereas there was no significant difference in the non-leftshifted group. Mean arterial pH was alkalotic in the leftshifted group and significantly higher than mean pH in the non-leftshifted group. It is concluded that DPG concentration cannot be calculated by the algorithm in patients with COPD and a leftward shift in the oxygen dissociation curve.