Blood Oxygen Research Articles

The effects of nutrition on mesenteric oxygenation among neonates with neonatal encephalopathy: a randomized clinical trial.

We aimed to evaluate the effects of minimal enteral nutrition (MEN) on mesenteric blood flow and oxygenation with Doppler USG and Near Infrared Spectroscopy (NIRS) during therapeutic hypothermia (TH) in babies with HIE. This prospective, randomized-controlled study was composed of infants receiving MEN (study group, n = 30) and infants who were not fed (control group, n = 30) during hypothermia. Infants were monitored continuously with NIRS and mesenteric blood flow velocities were measured with Doppler USG before and after feeding. The mean gestational age and birth weight for the study and control group were 38.73 ± 1.5-39.09 ± 1.02 weeks and 3076 ± 280.4-3295 ± 391 grams, respectively. Time to reach full enteral nutrition and hospital stay were significantly shorter in the study group (p = 0.049, p = 0.016). Infants in the study group experienced less feeding intolerance (p = 0.006). No infant developed necrotizing enterocolitis (NEC) in both groups. No difference was determined in pre- and post-feeding cerebral rSO2 measurements during TH and normothermia. Mesenteric rSO2, CSOR, and mesenteric blood flow measurements in the study group during normothermia were significantly increased, respectively (p = 0.03, p < 0.01, p < 0.01). In our study, we observed that MEN during TH does not lead to a significant change in cerebral and mesenteric oxygenation. Although we did not observe an increase in blood flow and oxygenation, the absence of NEC and a lower incidence of feeding intolerance in the study group may suggest that feeding during TH is safe and feasible. MEN during TH treatment does not lead to a significant change in cerebral and mesenteric oxygenation. This is the first study evaluating the effects of MEN on mesenteric oxygenation and blood flow velocities in infants with hypoxic-ischemic encephalopathy during TH with Doppler USG and NIRS, concomitantly. MEN during TH may be safe and feasible.

Percutaneous Wearable Biosensors: A Brief History and Systems Perspective

AbstractWearable biosensors are envisioned to disrupt both delivery and accessibility of healthcare by providing real‐time, continuous monitoring of informative and predictive physiological markers in convenient, user‐friendly, and portable designs. In recent years, there has been myriad demonstrations of biosensor‐integrated clothing and skin‐borne biosensor patches, enabled by device miniaturization, reduced power consumption, and new biosensing chemistries. Despite these impressive demonstrations, most consumer‐grade wearables have been limited to biophotonic and biopotential sensing methods to extrapolate information such as pulse, blood oxygenation, and electrocardiograms. The only commercial example of wearable electrochemical sensing methods is for glucose monitoring. However, there is a growing interest in developing percutaneous biosensors for monitoring in interstitial fluid (ISF), which offers direct access to popular analytes such as glucose, lactate, and urea, as well as new targets like hormones, antibodies, and even medications. Herein, a brief context for the current status of wearable biosensors is provided and assess the major engineering successes and pitfalls of percutaneous biosensors over the past five years, with a view to identifying areas for further developments that will enable deployable, clinical‐ or consumer‐grade systems.

Investigation of Changes in the Reflection Spectrum of Human Blood When Exposed to Laser Radiation With Wavelengths of 450 or 980 nm.

This study aimed to determine and explain changes in the reflectance spectrum of human blood in vitro when exposed to laser radiation at wavelengths of 450 or 980 nm. Reflectance spectra of venous blood samples were measured before and after exposure to a single pulse of 450 or 980 nm laser radiation. A numerical optical model based on the Monte Carlo method was applied. Laser irradiation at 450 and 980 nm caused the most significant changes in the reflectance spectrum around 600 nm, associated with alterations in blood oxygen saturation. The maximum efficiency of reducing oxygen saturation was 0.20%/W for 980 nm and 0.72%/W for 450 nm, likely due to differences in blood absorption at these wavelengths. The greatest change in intensity reflectance spectra and oxygen saturation of human venous blood occurs when exposed to laser radiation at 450 nm, not at 980 nm.

Perfusion index as an early predictor of hypotension during advanced oncothoracic operations (pilot study)

Introduction. Current standards of intraoperative monitoring significantly reduce the response time to a decrease in blood pressure, but do not include methods for predicting changes in hemodynamics to avoid the effects of systemic hypoperfusion.The objective was to evaluate the usefulness of determining the perfusion index for predicting the development of hypotension and its earlier correction during advanced oncothoracic operations.Materials and methods. A prospective open-label observational study was conducted, which included 100 patients who underwent elective oncothoracic surgery. Standard monitoring was established, as well as continuous monitoring of the perfusion index. The perfusion index value was recorded immediately before induction. The patients were divided into 2 groups: in the 1st group (n = 37), patients experienced a decrease in blood pressure, requiring vasopressor support; in the 2nd group (n = 63), no vasopressor support was required.Results. A moderate linear relationship was revealed with a correlation coefficient (r) equal to (–0.68), p &lt; 0.001, and a strong non-linear relationship with a coefficient (ρ) equal to (–0.95), p &lt; 0.001. To identify the relationship model, polynomial regression analysis was performed. A prognostic formula for the use of vasopressors was calculated depending on the preoperative level of perfusion index. At the next stage, a classification tree for analyzing the data array was used. The entire d data array (n = 100) is randomly divided into training (n = 70) and test samples (n = 30). It was revealed that hypotension requiring vasopressor support occurred in patients whose initial perfusion index was ≤ 2.85. ROC analysis determined an AUC of 0.952 (95% CI: 0.888–1.016).Conclusion. A low PI value before induction of anesthesia during advanced oncothoracic operations can be used to monitor the functional activity of the autonomic nervous system and predict intraoperative hypotension. Patients with a baseline PI ≤ 2.85 have a higher risk of developing hypotension during advanced oncothoracic surgery compared with those with a baseline PI ≥ 2.85. The effectiveness of the method in patients with concomitant pathologies has not been tested.

STATE OF HAEMODYNAMICS AND OXYGEN BUDGET IN THE PERIOPERATIVE PERIOD IN PATIENTS WITH OSTEOARTHRITIS AND CONCOMITANT CARDIAC PATHOLOGY DURING TOTAL HIP ARTHROPLASTY SURGERY DEPENDING ON THE TYPE OF SURGICAL ACCESS

Summary. Aim. To compare the hemodynamic status and oxygen budget in patients with osteoarthritis and comorbid cardiac pathology during total hip arthroplasty, based on the type of surgical approach used. Materials and Methods. The study analyzed the treatment outcomes of 90 patients with stage 3-4 osteoarthritis of the hip who underwent total cemented hip arthroplasty. All patients were divided into two groups according to the surgical approach (traditional posterior or modified posterior). The study was conducted at the following stages: before surgery, immediately after surgery, 24 hours post-surgery, and one week after surgery. The following parameters were recorded: hemodynamic parameters (heart rate, systolic blood pressure, diastolic blood pressure, mean arterial pressure, and central venous pressure) and oxygen budget parameters (hemoglobin (Hb), lactate, hematocrit (Ht), oxygen saturation of hemoglobin in arterial and venous blood (SaO2 and SvO2), partial pressure of oxygen in arterial and venous blood (paO2 and pvO2)). Based on these data, the following indices were calculated: left ventricular ejection fraction (LVEF), cardiac index (CI); oxygen content in arterial and venous blood (CaO2 and CvO2), arteriovenous oxygen content difference (C(a-v)O2), oxygen transport (TO2), oxygen consumption (VO2); systemic perfusion pressure (SPP), blood flow power (BFP), oxygen reserve (OR), and circulatory reserve (CR). Results. The use of the modified posterior approach positively influenced hemodynamic parameters. After the surgery and on the 7th day post-surgery, SPP was significantly lower with the modified posterior approach. The CI was also significantly affected by the modified posterior approach. Throughout the study, except for the first stage, CI was significantly higher when using the modified posterior approach. LVEF increased significantly with both approaches, but on the 7th day post-surgery, it was significantly higher in the second group. BFP did not statistically differ between the two groups throughout the study, but its energy efficiency was lower, primarily due to the arteriovenous oxygen content difference (C(a-v)O2). C(a-v)O2 was the same before surgery for both approaches. At subsequent stages of the study, the differences between the groups increased, and on the 7th day, they were the most significant, with C(a-v)O2 being lower after using the modified posterior approach. The energy efficiency of blood flow was assessed by calculating OR and CR. Both indicators were significantly higher during the study, except at the preoperative stage, when using the modified posterior approach. Conclusions. Our study clearly demonstrates the benefits of implementing the modified posterior approach in total hip arthroplasty for patients with osteoarthritis and comorbid cardiac pathology. This approach improves hemodynamic and oxygen budget parameters compared to the traditional approach, which can significantly impact treatment outcomes for patients with cardiac comorbidity and reduce the number of postoperative complications.

Concentric-object and equiangular-object methods to perform standardized regional analysis in renal mpMRI.

Renal multiparametric magnetic resonance imaging (mpMRI) sequences, including T1-T2 mapping, Blood oxygenation level-dependent (BOLD), Renal blood flow (RBF), and Apparent Diffusion Coefficient (ADC) from diffusion-weighted imaging (DWI), provide insights into kidney function. However, consensus on selecting regions of interest (ROIs) is lacking. This study aims to describe and compare the Concentric Objects (CO) and Equiangular Objects (EO) methods for standardized ROI selection and assess their efficacy in capturing regional variations in renal MRI parameters. Twelve healthy volunteers underwent mpMRI renal scans. ROIs were selected manually and by applying the CO and EO algorithms to each mpMRI sequence. The methods were tested across various subregion configurations. Regional differences in renal MRI parameters were evaluated. CO and EO methods demonstrated statistically significant differences in mpMRI parameters across renal regions. ASL-RBF, BOLD-MRI, and T2-map results indicated substantial variations from the lower to upper kidney areas. This study implemented CO and EO algorithms in renal mpMRI, showing their potential for evaluating cortico-medullary and cranio-caudal profiles. The findings validate the CO method for BOLD and ADC measurements and presented ASL-RBF and T1-T2 map profiles. The EO method's utility needs further validation with renal patients.

A Study of Data Processing Methods for Non-Contact Multispectral Method of Blood Oxygen Saturation.

Regular monitoring of blood oxygenation is important for disease prevention and treatment. Image photoplethysmography (IPPG) technology is a non-contact physiological parameter detection technology, which has been widely used in blood oxygenation detection. However, traditional imaging devices still have issues such as low detection accuracy, narrower receiving spectral range. In this paper, we proposed two improved detection methods based on the dual-wavelength measurement principle, that is, dual-band IPPG signal ratio method and dual-band IPPG signal AC/DC method. To verify the effectiveness of the two methods, we used different heartbeat period IPPG signals as sample data sets, and combined PLS and RF algorithms for model training, thus obtaining the best data processing method. The experimental results showed that the dual-band IPPG signal AC/DC method can effectively reduce the model training time. This method meets the strong demand for non-contact blood oxygen measurement and provides a new measurement idea.

The Pathophysiology and Biomarkers of Delirium.

Delirium is a major disturbance in the mental state characterized by fluctuations in arousal, deficits in attention, distorted perception, and disruptions in memory and cognitive processing. Delirium affects approximately 18% to 25% of hospital inpatients, with even higher rates observed during critical illness. To develop therapies to shorten the duration and limit the adverse effects of delirium, it is important to understand the mechanisms underlying its presentation. Neuroimaging modalities such as magnetic resonance imaging (MRI), positron emission tomography, functional MRI, and near-infrared spectroscopy point to global atrophy, white matter changes, and disruptions in cerebral blood flow, oxygenation, metabolism, and connectivity as key correlates of delirium pathogenesis. Electroencephalography demonstrates generalized slowing of normal background activity, with pathologic decreases in variability of oscillatory patterns and disruptions in functional connectivity among specific brain regions. Elevated serum biomarkers of inflammation, including interleukin-6, C-reactive protein, and S100B, suggest a role of dysregulated inflammatory processes and cellular metabolism, particularly in perioperative and sepsis-related delirium. Emerging animal models that can mimic delirium-like clinical states will reveal further insights into delirium pathophysiology. The combination of clinical and basic science methods of exploring delirium shows great promise in elucidating its underlying mechanisms and revealing potential therapeutic targets.

Effect of Tenofovir Alafenamide Fumarate on the outcomes of hospitalized COVID-19 patients: a prospective, block-balanced, open-label, randomized controlled trial

BackgroundThe global effort to cure COVID-19 is still ongoing. Thus, a prospective, block-balanced, open-label, randomized controlled trial was conducted to evaluate how Tenofovir Alafenamide Fumarate affects hospitalized COVID-19 patients’ outcomes.MethodsThe intervention and control groups of 60 hospitalized COVID-19 patients were randomly allocated. Along with normal medication, the intervention group received 25 mg of tenofovir orally daily for seven days. The control group got normal therapy, including remdesivir and corticosteroids. ICU hospitalization duration, laboratory data, fever, dyspnea, arterial blood oxygen saturation with and without an oxygen face mask, mechanical ventilation, and mortality were the outcomes.ResultsSixty of 236 eligible patients between September 2020 and February 2021 were enrolled. The intervention group had a mean age (±SD) of 61.33 (±13.09) years and the control group 60.03 (±18.03). Sixteen (53.3%) intervention patients and 15 (50.0%) control patients were males. The intervention group had fewer mechanical ventilation and ICU days. Tenofovir Alafenamide Fumarate did not improve fever, dyspnea, oxygen saturation with or without a face mask or nasal cannula, or laboratory data including WBC, ESR, CRP, AST, ALT, AlkP, total and direct bilirubin, in COVID-19 patients.ConclusionAccording to this pilot trial, Tenofovir Alafenamide Fumarate, along with conventional treatment, significantly reduced mechanical ventilation and ICU stay in COVID-19 patients. Further thorough research is necessary to verify this conclusion.

Cohort Profile: TRacing Etiology of Non-communicable Diseases (TREND): Rationale, Progress and Perspective

AbstractThe TRacing Etiology of Non-communicable Diseases (TREND) cohort is a prospective longitudinal cohort and biobank that is mainly based in Ma’anshan, Anhui Province, China. The primary aim of the study is to decipher comprehensive molecular characterization and deep phenotyping for a broad spectrum of chronic non-communicable diseases (NCDs), which focuses on providing mechanistic insights with diagnostic, prognostic and therapeutic implications. The recruitment was initiated in 2023 and is expected to complete in 2025 with 20,000 participants originated from urban and rural area. In the first phase, 3360 participants were recruited. Follow-up visits are scheduled annually and intervally for a total of 30 years. The cohort includes individuals aged over 18 years. Two participants with first-degree linkage were recruited from a household. The age distribution of recruited participants was stratified into four categories: 18–45, 45–55, 55–65, and ≥65 years, aligning with the population proportions of Ma’anshan. Meanwhile, the gender distribution was controlled by pairing men and women from the same household. Data collected at baseline includes socio-economic information, medical history, lifestyle and nutritional habits, anthropometrics, blood oxygen, electrocardiogram (ECG), heart sound, as well as blood, urine and feces tests results. Molecular profiling includes genome, proteome, metabolome, microbiome and extracellular vesicles -omics. Blood, urine and fecal samples are collected and stored at −80 °C in a storage facility for future research.

Predictive values and correlation of CRIB Score II and perfusion index in assessment of severity of illness in sick preterm neonates: An observational study.

Perfusion index (PI) and CRIB (Clinical risk index of babies) Score II both are minimally invasive tools for prediction of mortality and morbidity in sick neonates. This study aims to know the predictive values of both PI and CRIB Score II in assessment of severity of illness in preterm neonates of 28 to 32 weeks and their correlation. PI and CRIB II Score of 125 sick preterm neonates admitted in NICU were assessed within 12 hours of admission. Severity noted in form of outcome. Correlation between PI and CRIB Score II were observed. Receiver operating characteristic (ROC) curve were plotted for PI and CIRB Score II with outcome (discharged vs expired). Area under curve for perfusion index was 0.776 at 95% confidence interval. Optimum cutoff point based on ROC curve was 1.65 with sensitivity of 84%., specificity of 37.2% with positive predictive value of 70% and negative predictive value of 57%. Area under curve for CRIB Score II was 0.622 (p value < 0.028), optimum cut off point based on ROC curve for CRIB II score was 3.5 with sensitivity 79.10% of specificity of 40% positive predictive value is 43.03% and negative predictive value of 76.9%. Spearman's correlation coefficient between PI and CRIB II score was -0.272 and p value is 0.002. This study concluded that perfusion index (p < 0.001) is better for predicting the severity compared to CRIB II score (p < 0.028). A weak negative correlation exists between PI and CRIB II score (r = -0.272).

Coronary circulation enhances the aerobic performance of wild Pacific salmon.

Female Pacific salmon often experience higher mortality than males during their once-in-a-lifetime up-river spawning migration, particularly when exposed to secondary stressors (e.g. high temperatures). However, the underlying mechanisms remain unknown. One hypothesis is that female Pacific salmon hearts are more oxygen-limited than those of males and are less able to supply oxygen to the body's tissues during this demanding migration. Notably, female hearts have higher coronary blood flow, which could indicate a greater reliance on this oxygen source. Oxygen limitations can develop from naturally occurring coronary blockages (i.e. coronary arteriosclerosis) found in mature salmon hearts. If female hearts rely more heavily on coronary blood flow but experience similar arteriosclerosis levels as males, they will have disproportionately impaired aerobic performance. To test this hypothesis, we measured resting (RMR) and maximum metabolic rate (MMR), aerobic scope (AS) and acute upper thermal tolerance in coho salmon (Oncorhynchus kisutch) with an intact or artificially blocked coronary oxygen supply. We also assessed venous blood oxygen and chemistry (cortisol, ions and metabolite concentrations) at different time intervals during recovery from exhaustive exercise. We found that coronary blockage impaired MMR, AS and the partial pressure of oxygen in venous blood (PvO2) during exercise recovery but did not differ between sexes. Coronary ligation lowered acute upper thermal tolerance by 1.1°C. Although we did not find evidence of enhanced female reliance on coronary supply, our findings highlight the importance of coronary blood supply for mature wild salmon, where migration success may be linked to cardiac performance, particularly during warm water conditions.

Photobiomodulation therapy on puncture-associated pain: A controlled randomized double-blind clinical trial.

Dental fear and phobia are prevalent worldwide, with local anesthesia being the most feared procedure. This study aimed to determine whether photobiomodulation therapy (PBMT), used as a pre-anesthetic, could modulate puncture pain and enhance the effectiveness of local anesthesia. In this controlled, randomized, double-blind study, 49 participants were divided into an experimental group (n = 24), which received infrared laser therapy (100 mW, at 808 nm, 8 J, 80 s at a single point) immediately before standard anesthesia; and control group (n = 25), which received the standard anesthetic technique and sham laser. Pain levels were measured using the visual analog scale, and anesthetic efficacy was assessed through electrical tests (latency), percentage of failures, and cartridge usage. Anxiety levels were evaluated using the Beck Anxiety Inventory. Cardiovascular parameters were evaluated through blood pressure, oxygen levels, and heart rate. This randomized, double-blind study found no difference between groups in these experimental conditions. The bias toward a positive PBMT result was sufficiently removed. Autonomic responses of the PBMT group were maintained stable during the procedure.

Safety, feasibility, and acceptability of a novel device to monitor ischaemic stroke patients

This study assessed the safety, feasibility, and acceptability of a novel device to monitor ischaemic stroke patients. The device captured electroencephalography (EEG) and electrocardiography (ECG) data to compute an ECG-based metric, termed the Electrocardiography Brain Perfusion index (EBPi), which may function as a proxy for cerebral blood flow (CBF). Seventeen ischaemic stroke patients wore the device for nine hours and reported feedback at 1, 3, 6 and 9 h regarding user experience, comfort, and satisfaction (acceptability). Safety was assessed as the number of adverse events reported. Feasibility was assessed as the percentage of uninterrupted EEG/ECG data recorded (data capture efficiency). No adverse events were reported, only minor incidences of discomfort. Overall device comfort (mean ± 1 standard deviation (SD) (range)) (92.5% ± 10.3% (57.0–100%)) and data capture efficiency (mean ± 1 SD (range)) (95.8% ± 6.8% (54.8–100%)) were very high with relatively low variance. The device didn’t restrict participants from receiving clinical care and rarely (n = 6) restricted participants from undertaking routine tasks. This study provides a promising evidence base for the deployment of the device in a clinical setting. If clinically validated, EBPi may be able to detect CBF changes to monitor early neurological deterioration and treatment outcomes, thus filling an important gap in current monitoring options. TRIAL REGISTRATION: The study was prospectively registered with the Australian New Zealand Clinical Trials Registry (ACTRN12622000112763).

Hyperspectral imaging of human liver allografts for prediction of initial graft function

PurposeIschemia reperfusion injury represents a significant yet difficult to assess risk factor for short- and long-term graft impairment in human liver transplantation (LT). As a non-invasive, non-ionizing tool, hyperspectral imaging (HSI) is capable of correlating optical properties with organ microperfusion. Hence, we here performed a study of human liver allografts assessed by HSI for microperfusion and prediction of initial graft function.MethodsImages of liver parenchyma of 37 human liver allografts were acquired at bench preparation, during normothermic machine perfusion (NMP), if applicable, and after reperfusion in the recipient. A specialized HSI acquisition software computed oxygen saturation (StO2), tissue hemoglobin indices (THI), near infrared perfusion indices (NIR), and tissue water indices (TWI). HSI parameters were analyzed for differences with regard to preservation technique, reperfusion sequence and presence of early allograft dysfunction (EAD).ResultsOrgan preservation was performed by means of NMP (n = 31) or static cold storage (SCS; n = 6). Patients’ demographics, donor characteristics, presence of EAD (NMP 36.7% vs. SCS 50%, p = 0.6582), and HSI parameters were comparable between both groups of preservation method. In organs developing EAD, NIR at 1, 2, and 4 h NMP and after reperfusion in the recipient was significantly lower (1 h NMP: 18.6 [8.6–27.6] vs. 28.3 [22.5–39.4], p = 0.0468; 2 h NMP: 19.4 [8.7–30.4] vs. 37.1 [27.5–44.6], p = 0.0011; 4 h NMP: 26.0 [6.8–37.1] vs. 40.3 [32.3–49.9], p = 0.0080; reperfusion: 13.0 [11.5–34.3] vs. 30.6 [19.3–44.0], p = 0.0212).ConclusionHSI assessment of human liver allografts is feasible during organ preservation and in the recipient. NIR during NMP and after reperfusion might predict the onset of EAD. Larger trials are warranted for assessment of this novel technique in human LT.

Somatosensory migraine auras evoked by bihemispheric cortical spreading depression events in human parietal cortex.

Cortical spreading depression (CSD) is associated with pronounced alterations in cerebral blood flow. These alterations can be captured using high-field functional magnetic resonance imaging (fMRI). While compelling clinical and experimental data suggest that CSD is involved in the pathogenesis of migraine aura, the mechanistic intricacies remain poorly understood. Here, we use visual stimulus-induced blood oxygen level-dependent (BOLD) fMRI responses to characterize spatiotemporal alterations in cerebral blood flow during spontaneous attacks with migraine aura. Six adult participants diagnosed with migraine with aura underwent BOLD fMRI scans with a visual stimulation paradigm, consisting of flickering checkerboard stimulation. Our results revealed that auras with somatosensory symptoms corresponded with bilateral alterations of stimulus-induced BOLD responses in the somatosensory cortex, exhibiting anterior-to-posterior propagation and absence of antecedent occipital abnormalities. These altered stimulus-induced BOLD responses were bilateral, despite a unilateral manifestation of aura symptoms, and had no relationship with positive or negative aura symptoms. The bilateral abnormalities in stimulus-induced BOLD responses completes our current knowledge on migraine aura.

Asymmetric spin echo multi-echo echo planar imaging (ASEME-EPI) sequence for pre-clinical high-field fMRI.

In functional magnetic resonance imaging (fMRI) of the blood oxygen level-dependent (BOLD) contrast, gradient-recalled echo (GRE) acquisitions offer high sensitivity but suffer from susceptibility-induced signal loss and lack specificity to microvasculature. In contrast, spin echo (SE) acquisitions provide improved specificity at the cost of reduced sensitivity. This study introduces Asymmetric Spin Echo Multi-Echo Echo Planar Imaging (ASEME-EPI), a technique designed to combine the benefits of both GRE and SE for high-field preclinical fMRI. ASEME-EPI employs a spin echo readout followed by two asymmetric spin echo (ASE) GRE readouts, providing an initial T2-weighted SE image and subsequent T2 * -weighted ASE images. A feasibility study for the technique was implemented on a 9.4 T pre-clinical MRI system and tested using a visual stimulation in northern tree shrews. Comparing ASEME-EPI with conventional GRE echo planar imaging (GRE-EPI) and SE echo planar imaging (SE-EPI) acquisitions, results showed that ASEME-EPI achieved BOLD contrast-to-noise ratio (CNR) comparable to GRE-EPI while offering improved specificity in activation maps. ASEME-EPI activation was more confined to the primary visual cortex (V1), unlike GRE-EPI which showed activation extending beyond anatomical boundaries. Additionally, ASEME-EPI demonstrated the ability to recover signal in areas of severe field inhomogeneity where GRE-EPI suffered from signal loss. The performance of ASEME-EPI is attributed to its multi-echo nature, allowing for SNR-optimized combination of echoes, effectively denoising the data. The inclusion of the initial SE also contributes to signal recovery in areas prone to susceptibility artifacts. This feasibility study demonstrates the potential of ASEME-EPI for high-field pre-clinical fMRI, offering a promising compromise between GRE sensitivity and SE specificity while addressing challenges of T2 * decay at high field strengths.

Comparing the Effect of Granisetron with Meperidine on Post-Shivering in Elective Cesarean Section under Spinal Anesthesia

Background: Post-operative shivering after spinal anesthesia is a common issue in women undergoing cesarean section, then its management is necessary to increase patients’ satisfaction. Therefore, the current study aimed to compare the prophylactic effect of Granisetron and meperidine on post-spinal shivering in elective cesarean section. Methods: In this double-blinded clinical trial study, 100 women under elective cesarean section using block randomization were divided into two groups. The spinal anesthesia was performed in all women with 10 mg hyperbaric bupivacaine 0.5 %. Then, after the birth of the baby, the patients received 0.04 mg/kg Granisetron or 0.4 mg/kg meperidine intravenously. Mean Arterial Pressure (MAP), Heart Rate (HR), and percentage of arterial blood oxygen saturation (SpO2) were measured before intervention and 60 minutes after surgery using a standard monitoring device. Shivering was evaluated 30 minutes after the surgery in the recovery room according to the clinical examinations. Results: The changes in hemodynamics parameters were similar between the two groups. There was a statistically significant difference in the rate of shivering between the two groups. The rate of shivering in the Granisetron group was higher than in the meperidine group. Thus, 13 patients (26%) and 5 patients (10%) had shivering in the Granisetron and meperidine groups, respectively (p=0.037). Conclusion: Granisetron was not more effective than meperidine as routine treatment in preventing shivering after spinal anesthesia in women under elective cesarean section.

Dual-ratio approach to pulse oximetry and the effect of skin tone.

Pulsatile blood oxygen saturation ( ) via pulse oximetry is a valuable clinical metric for assessing oxygen delivery. Individual anatomical features, including skin tone, may affect current optical pulse oximetry methods. We developed an optical pulse oximetry method based on dual-ratio (DR) measurements to suppress individual anatomical confounds on . We designed a DR-based finger pulse oximeter, hypothesizing that DR would suppress confounds from optical coupling and superficial tissue absorption. This method is tested using Monte Carlo simulations and in vivo experiments. Different melanosome volume fractions in the epidermis, a surrogate for skin tone, cause changes in the recovered on the order of 1% in simulation and in vivo. Different heterogeneous pulsatile hemodynamics cause greater changes on the order of 10% in simulations. recovered with DR measurements showed less variability than the traditional single-distance (SD) transmission method. For the models and methods considered here, measurements are strongly impacted by heterogeneous pulsatile hemodynamics. This variability may be larger than the skin tone bias, which is a known confound in measurements. The partial suppression of variability in the recovered by DR suggests the promise of DR for pulse oximetry.

Evaluation of lateral sagittal infraclavicular block according to inferior vena cava collapsibility index (VCI-CI): An observational study.

Depending on the total amount of fluid, changes occur in the amount of fluid in the peripheral area. The aim of this study was to observe the differences caused by hemodynamic changes after lateral sagittal infraclavicular block (LS-ICB) according to the inferior vena cava collapsibility index (VCI-CI). In this prospective, observational study (Clinical Trial Number: NCT05968105), patients undergoing elective hand and wrist surgery with LS-ICB were classified according to VCI-CI, with Group 1 defined as inferior vena cava (VCI) diameter < 1.5 cm and VCI-CI > 50% and Group 2 defined as VCI diameter > 1.5 cm and VCI-CI < 50%. Groups were compared for demographic characteristics, defined durations, rescue analgesics, and complications. Continuous hemodynamic parameters and pulsed wave Doppler were evaluated within groups. Demographic characteristics and time periods were comparable between the groups. Hemodynamic parameters and pulsed wave Doppler measurements showed no significant differences. However, while Group 1 remained consistent, Group 2 exhibited differences in axillary artery diastolic diameter and axillary artery contractility index. A significant statistical difference was observed in Group 1 for the perfusion index at 30 minutes and postoperatively, whereas Group 2 remained consistent. The dosage and number of patients requiring rescue analgesics were similar across both groups, and no complications were reported. Blood flow increased after LS-ICB without a corresponding increase in axillary artery diameter. Group 1 showed a tendency toward a lower perfusion index in the postoperative period.