Changes In Hemoglobin Concentration Research Articles

Biomarkers in Alzheimer's disease: Evaluation of platelets, hemoglobin and vitamin B12.

ABSTRACTCurrently, the most likely hypotheses as the cause of Alzheimer’s disease are deposition of amyloid beta peptide in the cerebral cortex and hyperphosphorylation of Tau protein. The diagnosis of Alzheimer’s disease is based on the exclusion of other diseases, behavioral assessments, and blood and imaging tests. Biotechnology has created interesting perspectives for the early detection of Alzheimer’s disease through blood analysis, with special attention to platelets, hemoglobin and vitamin B12.Objective:To evaluate the concentrations of platelets, hemoglobin and vitamin B12 in the blood of older adults with and without dementia of Alzheimer’s disease.Methods:A case-control study involving 120 individuals was conducted, seeking to establish a correlation between changes in platelet, hemoglobin and vitamin B12 concentrations in patients with confirmed AD and in individuals in the inclusion group without AD. The study met the established ethical requirements.Results:Hemoglobin and platelet levels were statistically lower in patients with AD. The biochemical evaluation in AD patient and healthy groups for vitamin B12 showed a decrease in the levels of this compound in patients with AD.Conclusion:We demonstrated the feasibility of the use of blood biomarkers as predictive markers for the diagnosis of AD.

Relationship Between Cerebral Blood Oxygenation and Electrical Activity During Mental Stress Tasks: Simultaneous Measurements of NIRS and EEG.

The incidence of stress-induced psychological and somatic diseases has been increasing rapidly, and it is important to clarify the neurophysiological mechanisms of stress response in order to establish effective stress management methods. We previously reported that the prefrontal cortex (PFC) plays an important role in stress response. In the present study, we employed near-infrared spectroscopy (NIRS) and electroencephalography (EEG) to investigate the characteristics of PFC activity during mental arithmetic tasks. A two-channel NIRS device was used to measure hemoglobin (Hb) concentration changes in the bilateral PFC during a mental arithmetic task (2min) in normal adults. Simultaneously, EEG was used to also measure bilateral PFC activity during the same task. We evaluated concentration changes of oxy-Hb induced by the task while analyzing α wave changes using power spectrum analysis. It was observed that oxy-Hb in the bilateral PFC increased significantly during the task (p<0.05), while α wave power in the PFC decreased significantly (p<0.01). The present results indicate that mental stress tasks caused the activation of the bilateral PFC. Simultaneous measurements of NIRS and EEG are useful for evaluating the neurophysiological mechanism of stress responses in the brain.

Influence of contrast-reversing frequency on the amplitude and spatial distribution of visual cortex hemodynamic responses

Visual stimulation is one of the most commonly used paradigms for cerebral cortex function investigation. Experiments typically involve presenting to a volunteer a black-and-white checkerboard with contrast-reversing at a frequency of 4 to 16 Hz. The aim of the present study was to investigate the influence of the flickering frequency on the amplitude of changes in the concentration of oxygenated and deoxygenated hemoglobin. The hemoglobin concentrations were assessed with the use of a high resolution diffuse optical tomography method. Spatial distributions of changes in hemoglobin concentrations overlaying the visual cortex are shown for various stimuli frequencies. Moreover, the hemoglobin concentration changes obtained for different source-detector separations (from 1.5 to 5.4 cm) are presented. Our results demonstrate that the flickering frequency had a statistically significant effect on the induced oxyhemoglobin changes (p < 0,001). The amplitude of oxy hemoglobin concentration changes at a frequency of 8 Hz was higher in comparison with that measured at 4 Hz :[median(25th-75thpercentiles) 1.24 (0.94-1.71) vs. 0.92(0.73-1.28)µM, p < 0.001]; 12 Hz:[1.24 (0.94-1.71) vs. 1.04 (0.78-1.32) µM, p < 0.001]; and 16 Hz:[1.24 (0.94-1.71) vs. 1.15(0.87-1.48) µM, p < 0.001]. No significant differences were observed between the size of an area of activation for various frequencies. The demonstrated superiority of 8 Hz over other frequencies can advance understanding of visual stimulations and help guide future fNIRS protocols.

Small-Volume Tubes to Reduce Anemia and Transfusion (STRATUS): A Pragmatic Stepped Wedge Cluster Randomized Trial

Background: Intensive care unit (ICU) patients undergo frequent blood sampling for laboratory testing resulting in blood loss that contributes to anemia and red blood cell (RBC) transfusion. Only 10% of the blood collected is used for testing suggesting that lower sample volumes may reduce the incidence/severity of anemia and use of RBC transfusion without compromising care. Small-volume (soft-draw) Vacutainer® tubes for blood collection (2-3 mL) have the same cost, physical dimensions, and blood draw technique as standard-volume tubes (4-10 mL) and are compatible with laboratory analyzers. We previously conducted a mixed-methods pilot study (n=369) in which small-volume tubes were implemented in the ICU resulting in a 45% reduction in blood loss with acceptability to end-users and no increased frequency of inadequate samples. We are currently conducting the STRATUS trial, a multi-center stepped wedge cluster randomized trial to determine whether a policy of using small-volume blood collection tubes reduces RBC transfusion compared to standard-volume tubes in adult ICU patients. Using this design an intervention can be incorporated into everyday practice at a site of care (such as an ICU) where individual randomization is not feasible. It is ideal for studying the effectiveness and implementation of interventions that have a high likelihood of benefit and low risk of harm. Study Design and Methods: STRATUS is a pragmatic stepped wedge cluster randomized trial being conducted at 25 ICUs (clusters) in Canada over 18 months. At 6-week intervals (steps), 2 ICUs are randomly selected to switch from standard-volume tubes (control) to small-volume tubes (intervention) for blood sampling. All patients admitted to the ICU during the study period are enrolled with waived consent and undergo blood sampling using the allocated tubes. To be eligible for STRATUS, ICUs met the following criteria: (i) adult care only (≥18 years), (ii) unit size ≥14 beds, (iii) capacity for mechanical ventilation; (iv) use of standard-volume Vacutainer® blood collection tubes at baseline; and (v) availability of electronic administrative and laboratory information. The primary outcome is the number of RBC units transfused per patient during their ICU stay in patients admitted to ICU for ≥48 hours. Secondary outcomes include (i) number of RBC units transfused per patient for the entire cohort, (ii) percentage change in estimated blood loss; (iii) change in hemoglobin concentration from ICU admission to discharge adjusted for RBC transfusion; (iv) number of samples with inadequate volume for testing; (v) ICU and hospital mortality; and (vi) ICU and hospital length of stay. The study is approved by local and provincial research ethics boards. Data are collected from electronic administrative and health record sources. Assuming a power of 90% with a type I error of 5% (2-sided) and intra-cluster correlation coefficient (ICC) of 0.01, 25 sites with 729 patients per site (total 18,240 ICU patients) are required to detect a minimum difference of 5 units per 100 patients (or 2.5% reduction). As the interventions are applied in hospital, we expect minimal loss to follow-up. From trial initiation January 2, 2019 to August 1, 2019, 6 sites have been switched to small-volume blood collection tubes on schedule. Up to May 2, 2019 enrolment was 4,186 patients. Significance: STRATUS will determine whether the use of small-volume blood collection tubes reduces RBC transfusion in ICU patients using an innovative cluster trial design that incorporates the intervention into routine ICU practice. With electronic administrative and health record data collection and a clinically relevant primary outcome, this pragmatic trial has the potential to change blood collection practices widely. Disclosures Siegal: Portola: Honoraria; BMS-Pfizer: Honoraria; Novartis: Honoraria; Bayer: Honoraria; Leo Pharma: Honoraria; Aspen Pharma: Honoraria. Arnold:Novartis: Honoraria, Research Funding; Rigel: Consultancy, Research Funding; Bristol-Myers Squibb: Research Funding; Principia: Consultancy. Connolly:Bayer Healthcare: Consultancy, Research Funding; Bristol-Myers Squibb: Consultancy, Research Funding; Portola Pharmaceuticals: Consultancy, Research Funding; Daiichi Sankyo: Consultancy, Research Funding. Crowther:Octapharma: Membership on an entity's Board of Directors or advisory committees; Shionogi: Membership on an entity's Board of Directors or advisory committees; Alexion: Speakers Bureau; Asahi Kasei: Membership on an entity's Board of Directors or advisory committees; CSL Behring: Other: preparing educational material and/or providing educational presentations; Pfizer: Other: preparing educational material and/or providing educational presentations; Servier Canada: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; BMS Canada: Membership on an entity's Board of Directors or advisory committees, Research Funding; Bayer: Other: Data and Safety Monitoring Board, Research Funding, Speakers Bureau; Diagnostica Stago: Other: preparing educational material and/or providing educational presentations, Research Funding; Alnylam: Equity Ownership.

Moderate-Intensity Aerobic Exercise Restores Appetite and Prefrontal Brain Activity to Images of Food Among Persons Dependent on Methamphetamine: A Functional Near-Infrared Spectroscopy Study.

The brain prefrontal control system is critical to successful recovery from substance use disorders, and the prefrontal cortex (PFC) regulates striatal reward-related processes. Substance-dependent individuals exhibit an increased response to drug rewards and decreased response to natural, nondrug rewards. Short-term aerobic exercise can ameliorate craving and inhibitory deficits in methamphetamine users, but the effect of exercise on food reward is unknown. This study used functional near-infrared spectroscopy (fNIRS) to measure the effects of moderate- and high-intensity short-term aerobic exercise on prefrontal activity related to food images and recorded the subjective feelings of appetite in methamphetamine-dependent users. In total, 56 men who met the Diagnostic and Statistical Manual of Mental Disorders (Fifth Edition) criteria for methamphetamine dependence, with a mean (SD) body mass index of 24.7 (3.5) kg/m2 and age of 30.2 (5.1) years, were randomly assigned to one of two exercise groups: moderate intensity (n = 28; 65%–75% of maximum heart rate) and high intensity (n = 28; 76%–85% of heart rate maximum). Each group also performed a resting control session for 35 min 1 week before or after the exercise, in a counterbalanced order. Mean oxygenated hemoglobin concentration changes in the PFC when viewing visual food cues were assessed by fNIRS, and subjective feelings of appetite were self-rated using visual analog scales after moderate- or high-intensity aerobic exercise and after the resting control session. A continuous-wave NIRS device was used to obtain functional data: eight sources and seven detectors were placed on the scalp covering the PFC, resulting in 20 channels per participant. We found that moderate-intensity aerobic exercise significantly increased both, the activation of the left orbitofrontal cortex (OFC) to images of high-calorie food (P = 0.02) and subjective sensations of hunger (F(1,54) = 7.16, P = 0.01). To our knowledge, this study provides the first evidence that moderate-intensity aerobic exercise increases OFC activity associated with high-calorie food images and stimulates appetite in methamphetamine-dependent individuals. These changes suggest that exercise may reestablish the food reward pathway hijacked by drugs and restore sensitivity to natural rewards. This evidence may contribute to the development of specific exercise programs for populations with methamphetamine dependence.

The change in haemoglobin concentration between the first and third trimesters of pregnancy: a population study

BackgroundThe physiological fall in haemoglobin concentration from the 1st to the 3rd trimester of pregnancy is often quoted as 5 g/L. However, other studies have suggested varying levels of fall between 8 and 13 g/L. We evaluated the change in haemoglobin concentration between the 1st and 3rd trimesters of pregnancy in a multi-ethnic population of pregnant women.MethodsA retrospective cohort analysis of 7054 women with singleton pregnancies, giving birth during 2013–15 in a single urban maternity unit in England.We calculated the changes in haemoglobin concentration from 1st to 3rd trimester using the first trimester haemoglobin as the reference point. The population was stratified into sub-groups to explore any differences that existed within the population.ResultsIn general the fall in haemoglobin concentration was in the order of 14 g/L or 11% of the first trimester value. This fall was consistent for the majority of sub-groups of the population. The fall was lower (7.7%) in the most deprived section of the population, IMD1, but it increased to 11.7% when we restricted that sub-group to pregnant women without health problems during the index pregnancy. Conversely, there was an increase in haemoglobin of 10.2% in women whose first trimester haemoglobin concentration was in the lowest 5% of the total study population. The population fall in haemoglobin was 10.2 g/L (7.8%), after excluding cases above the 95th and below the 5th centiles, and women with a medical and/or obstetric disorder during the pregnancy.ConclusionThe fall in haemoglobin during pregnancy is in the order of 14 g/L or 11% of the first trimester level. This is 2 to 3 times higher than suggested by some guidelines and higher than previously published work. The results challenge the current accepted thresholds for practice, and have broader implications for diagnosis and managment of antenatal anaemia.Tweetable abstractFall in haemoglobin across pregnancy is around 14 g/L (11%) and significantly higher than previously stated in the pregnant population. This poses questions over currently accepted thresholds for anaemia in pregnancy.

Relationship of mottling score, skin microcirculatory perfusion indices and biomarkers of endothelial dysfunction in patients with septic shock: an observational study

BackgroundIn patients with septic shock, the skin is often chosen for the evaluation of peripheral perfusion and oxygenation. Changes in skin microcirculatory vessel oxygen saturation and relative hemoglobin concentration can be described using a mottling score or captured with hyperspectral imaging. However, the effectiveness of the mottling score in assessing microcirculation remains to be shown. We hypothesize that the mottling score in patients with septic shock is related to skin microcirculatory perfusion indices quantified by hyperspectral imaging, biomarkers that reflect endothelium activation and damage, and clinical outcome.MethodsHyperspectral imaging of the knee area was performed in 95 intensive care patients with septic shock enrolled in a single-center observational study to obtain relative oxy/deoxyhemoglobin concentration values and construct anatomical maps of skin microcirculatory saturation. The blood was sampled to obtain concentrations of thrombomodulin, plasminogen activator inhibitor-1 (PAI-1), soluble intercellular adhesion molecule-1 (ICAM-1), soluble vascular cell adhesion molecule-1 (VCAM-1), angiopoietin-2, and syndecan-1. The spectrophotometrically obtained skin microvascular perfusion indices were compared to the mottling score and biomarker concentration. The association between mottling score, skin microcirculatory perfusion indices, and 28-day mortality was also analyzed.ResultsMicrocirculatory oxygen saturation was significantly lower and total hemoglobin concentration was significantly higher in patients with a mottling score of 2 compared to those with a score of 0 (p = 0.02), with no difference between other scores. We found an association between microcirculatory oxygen saturation and PAI-1 levels (rho = − 0.3; p = 0.007). Increased mottling score and decreased microcirculatory oxygen saturation were predictive of 28-day mortality (mottling score 2 vs 0: OR 15.31, 95% CI 4.12–68.11; microcirculatory oxygen saturation: OR 0.90, 95% CI 0.85–0.95). Endothelial biomarkers did not increase the predictive value of skin microcirculatory perfusion indices.ConclusionsHigher mottling scores are associated with lower microcirculatory oxygen saturation but with significant overlap between scores. Microcirculatory oxygen saturation is a quantitative measure of peripheral oxygenation and is more specific than the mottling score in predicting 28-day mortality.

Intra-Dialytic Hemoglobin Changes and Cardiovascular Events: A Cohort Study on Dialysis Outcomes and Practice Patterns in Japan

Background: Ultrafiltration during hemodialysis (HD) causes hemoconcentration. Little is known about the relationships between intra-dialytic changes in hemoglobin concentration and cardiovascular events. Thus, this study aimed to elucidate the relationships between intra-dialytic changes in hemoglobin concentration and cardiovascular events among HD patients. Methods: This prospective cohort study was based on the Japanese Dialysis Outcomes and Practice Pattern Study phases 4 and 5. The predictor was the ratio of post-dialysis hemoglobin concentration to pre-dialysis hemoglobin concentration (post-Hb/pre-Hb) at baseline. The primary outcome was major adverse cardiovascular events (MACEs). Hazard ratios (HRs) were estimated using a Cox model for the association between post-Hb/pre-Hb and MACEs, adjusting for potential confounders. Results: A total of 865 patients were enrolled. During a median follow-up of 2.6 years, 145 (16.8%) patients developed MACEs. Patients were divided into 4 categories according to baseline post-Hb/pre-Hb (<1.0, ≥1.0 to <1.1, ≥1.1 to <1.2, and ≥1.2). The multivariable-adjusted HRs for MACEs were 1.69 (95% CI 1.36–2.10), 1.29 (95% CI 1.10–1.51), and 1.31 (95% CI 1.02–1.68) in patients with post-Hb/pre-Hb ratios of <1.0, ≥1.0 to <1.1, and ≥1.2, respectively, compared with the reference post-Hb/pre-Hb ratio of ≥1.1 to <1.2. Cubic spline analyses revealed a U-shaped association between post-Hb/pre-Hb and MACEs. Conclusion: High and low intra-dialytic changes in hemoglobin concentration are associated with a high risk of MACEs in patients undergoing HD.

Experimental reduction of nestling hemoglobin concentration in combination with ectoparasite load manipulation affects nestling morphology and begging behavior, but not adult behavior

Young nest-bound birds often face a diversity of ectoparasites that typically feed on blood and can negatively affect nestling morphological and physiological traits, including hemoglobin concentration. While hemoglobin concentration can be correlated with nestling performance, such as body mass, it is unknown whether variation in hemoglobin is the direct proximate factor responsible for variation in morphology, or if nestling traits simply co-vary with hemoglobin concentration due to a number of similar factors influencing both traits. If hemoglobin concentration does directly influence the phenotype of nestlings, then the reduction in nestling hemoglobin concentration by ectoparasites may cause other negative effects commonly associated with parasitism. By experimentally reducing the hemoglobin concentration of nestling Tree Swallows (Tachycineta bicolor) using phenylhydrazine hydrochloride (PHZ), we tested whether reduced hemoglobin concentration could be the mechanism that causes changes in nestling morphology and behavior in response to increased parasitism. Parasite loads were manipulated in conjunction with the PHZ treatment. Nestlings injected with PHZ displayed no change in hemoglobin concentration 2 days post-injection, whereas control nestlings showed the typical increase that occurs during early development. By 6 days post-injection, the parasite, but not PHZ, treatment significantly affected hemoglobin concentration. Both treatments interacted to affect begging intensity, while size and growth rate of nestlings were only affected by the parasite load manipulation. This study demonstrates the potential use of PHZ in nestlings to tease apart the effects of parasitism and reduced hemoglobin, but the results suggest incorporating a second injection of PHZ to better replicate the pattern of hemoglobin reduction created by hematophagous ectoparasites.

Efficiency of Pneumatic Tourniquet Cuff With Asymmetric Pressure Distribution at Rest and During Isometric Muscle Action

Ipavec, M, Grapar Žargi, T, Jelenc, J, and Kacin, A. Efficiency of pneumatic tourniquet cuff with asymmetric pressure distribution at rest and during isometric muscle action. J Strength Cond Res 33(9): 2570-2578, 2019-The aim of this study was to compare effects of newly designed double-chamber cuff with asymmetric pressure (APC) distribution and standard single-chamber cuff with symmetric pressure (SPC) distribution on muscle perfusion and volitional activation. First, the 2 cuffs were compared bilaterally on resting thigh muscles of 17 healthy volunteers at 4 cuff pressures (120, 160, 200, and 240 mm Hg). Then, the subjects performed the isometric endurance test of knee extensor muscles to volitional failure at 40% of maximal volitional isometric action in both free-flow and blood flow restricted condition. Changes in hemoglobin kinetics in vastus lateralis muscle (near-infrared spectroscopy), surface electromyography of vastus medialis muscle, and pain intensity (visual analogue scale [VAS]) were continuously recorded. At rest, a significant difference (p = 0.009) in velocity of change in total hemoglobin concentration was noted between the cuffs at 160 mm Hg (APC = 0.028 μM·s and SPC = 0.056 μM·s). The VAS scores significantly increased (p = 0.031) at pressures ≥200 mm Hg, with no difference between the cuffs. Duration of isometric action with blood flow restriction was 12% shorter (p = 0.003) than in free-flow condition, with no difference between the cuffs. There were no significant differences in muscle activation or hemoglobin kinetics between the exercise conditions or cuff types. The results show that APC reduces blood flow in quadriceps femoris muscle at rest at lower pressure than SPC, which suggests its enhanced efficiency for blood flow restriction. Given that application of either type of cuff during sustained isometric action had only minor impact on muscle endurance and oxygen kinetics, future research must focus primarily on dynamic muscle actions.

Breath-Hold Paradigm to Assess Variations in Oxygen Flow in Diabetic Foot Ulcers Using a Noncontact Near-Infrared Optical Scanner.

Objective: Diabetic foot ulcers (DFUs) occur in almost 25% of all patients with diabetes in their lifetime, with oxygen being the key limiting factor in healing. Identifying regions of compromised oxygenated flow can help clinicians cater the wound treatment process, possibly reducing wound healing time. Herein, a handheld, noncontact near-infrared optical scanner (NIROS) was developed and used to measure temporal changes in hemoglobin concentrations in response to a breath-hold (BH) paradigm. Approach: Noncontact imaging studies were carried out on DFU subjects and control subjects in response to a 20-s BH paradigm. Continuous-wave-based multiwavelength diffused reflective signals were acquired to generate effective oxy-hemoglobin, deoxy-hemoglobin, total hemoglobin, and oxygen saturation concentration maps using modified Beer-Lambert's law. Pearson's correlation analysis was carried out to determine variations in oxygen flow from hemoglobin concentration maps and the extent of variation observed in controls versus DFU subjects. Results: Temporal changes in hemoglobin concentration maps were observed in controls and DFU subjects. However, the oxygen flow in response to BH varied within 10% in all controls but significantly varied between wound and background regions in subjects with DFUs. Innovation: A method to assess variations in oxygen supply in and around DFUs was demonstrated using NIROS. This approach has potential to better cater DFU treatment process. Conclusion: Changes in all hemoglobin parameters due to 20 s of BH was observed. Pearson's analysis indicates that oxy-hemoglobin, deoxy-hemoglobin, and oxygen saturation fluctuations are synchronous in controls. In DFUs, changes are asynchronous with blood flow between the wound region and background region being significantly different.

Intravenous iron delivers a sustained (8-week) lowering of pulmonary artery pressure during exercise in healthy older humans.

In older individuals, pulmonary artery pressure rises markedly during exercise, probably due in part to increased pulmonary vascular resistance and in part to an increase in left‐heart filling pressure. Older individuals also show more marked pulmonary vascular response to hypoxia at rest. Treatment with intravenous iron reduces the rise in pulmonary artery pressure observed during hypoxia. Here, we test the hypothesis that intravenous iron administration may also attenuate the rise in pulmonary artery pressure with exercise in older individuals. In a randomized double‐blind placebo‐controlled physiology study in 32 healthy participants aged 50–80 years, we explored the hypothesis that iron administration would deliver a fall in systolic pulmonary artery pressure (SPAP) during moderate cycling exercise (20 min duration; increase in heart rate of 30 min−1) and a change in maximal cycling exercise capacity (V˙O2max). Participants were studied before, and at 3 h to 8 weeks after, infusion. SPAP was measured using Doppler echocardiography. Iron administration resulted in marked changes in indices of iron homeostasis over 8 weeks, but no significant change in hemoglobin concentration or inflammatory markers. Resting SPAP was also unchanged, but SPAP during exercise was lower by ~3 mmHg in those receiving iron (P < 0.0001). This effect persisted for 8 weeks. Although V˙O2max remained unaffected in the iron‐replete healthy participants studied here, this study demonstrates for the first time the ability of intravenous iron supplementation to reduce systolic pulmonary artery pressure during exercise.

P1.07: THE EFFECTS OF MINIMIZING PHLEBOTOMY BLOOD VOLUME ON ANEMIA IN PEDIATRIC HOME PARENTERAL NUTRITION PATIENTS

Background & Objectives: Anemia is a common morbidity in pediatric patients who require home parenteral nutrition (HPN). One factor that increases the risk for anemia in this patient population is frequent phlebotomy as part of routine monitoring. At Loma Linda University Children’s Hospital (LLUCH), the majority of pediatric patients on HPN have monthly labs drawn as part of the standard monitoring protocol. In June 2016, LLUCH began using micro-tubes for routine blood sampling. Traditional phlebotomy tubes require 15–20 mLof blood. Micro-tubes require less than 2mLfor the same tests. The purpose of this study is to understand the effects of phlebotomy blood volume minimization strategies in reducing anemia in our pediatric patients requiring HPN. Methods: This study was IRB-approved and retrospective in design. Since June 2016, the HPN program at LLUCH began using micro tubes for routine laboratory monitoring. Standard clinical data (age, gender, weight) and laboratory data (CBC, ALT, bilirubin, albumin) were collected prior to June 2016 and after September 2016. The primary outcome of this study was to compare the change in hemoglobin concentrations before and after the use of micro-tubes. The secondary outcome was to estimate the prevalence of anemia for age before and after use of micro-tubes for phlebotomy. Statistical analyses were performed including standard descriptive analysis, t-tests, and bivariate analysis. P-value of <0.05 was considered statistically significant. The sensitivity and specificity of red cell mean corpuscle volume (MCV) and red cell distribution width (RDW) in detecting anemia for ages were also calculated. Results: N = Thirty-eight subjects. Mean age = 6.1 years (SD +/- 4.2y). Prevalence of anemia for age before micro-tube implementation = 22% Prevalence of anemia for age after micro-tube implementation = 14% Mean difference in the hemoglobin of before and after implementation = +0.62g/dL(CI=0.21 to 1.02; p=0.004) Secondary bivariate analysis: No correlation between anemia for age and the following factors: age, gender, weight, ALT, and albumin level. Conclusions: Strategies such as micro-tubes to reduce the volume of routine blood draws in pediatric patients requiring chronic HPN may reduce the prevalence of anemia and improve hemoglobin levels. Age, weight, and liver enzyme levels were not found to be independent risk factors for the presence of anemia for age.

Influence of intra-abdominal pressure on the amplitude of fluctuations of cerebral hemoglobin concentration in the respiratory band

An intra-abdominal pressure (IAP) is correlated with cerebral perfusion, in a mechanism of reducing venous outflow. The elevated intra-abdominal pressure leads to an increase in the intracranial pressure and a decrease in the cerebral perfusion pressure. We studied the relationship between the IAP and the cerebral oxygenation with the use of the near infrared spectroscopy technique during a gynecological surgery. The changes in hemoglobin concentrations were analyzed in the time-frequency domain in the frequency band related to respiration. The measurements were carried out in 15 subjects who underwent laparoscopic surgery. During the laparoscopy, the intra-abdominal cavity was insufflated with CO2, which caused a controlled increase in the IAP. It was observed that the amplitudes of respiration-related waves present in hemoglobin concentration signals show an increase of 1.5 to 8.5 times during elevation of the IAP by 15 mmHg.

Changes in Plasma Haemoglobin Concentration in Citrate Phosphate Dextrose Adenine-1(CPDA-1) Stored Blood

Aim: This study assessed the level of plasma haemoglobin concentration in CPDA-1 stored blood with a view to determine the extent of haemolysis during the 35 days storage period.&#x0D; Study Design: This is an observational and comparative case-control study.&#x0D; Place and Duration of Study: The study was conducted using healthy male donors residing in Port Harcourt. Analysis was carried out at the Blood Bank of Rivers State University Teaching Hospital, formerly Braithwaite Memorial Specialist Hospital (BMSH), Port Harcourt, Nigeria, from February 1st to March 8th, 2017.&#x0D; Methodology: Blood for transfusion was collected from prospective male blood donor found to be in good health, aged between 18 and 52 years, with haemoglobin level within the range of 13.5 g/dl – 16 g/dl, body weight within 55 kg – 75 kg, and body temperature within 37.0 to 37.50C / 99.50F, into plastic bags containing anticoagulant CPDA-1, and handled under strict sterile condition to prevent bacterial contamination. The blood was stored in a blood bank refrigerator with a constant temperature of +2 to +60C under proper inspection at intervals for colour, turbidity, haemolysis and clot formation. Two milliliters of the sample was collected aseptically at different interval days of collection from the blood bag and analyzed using the HemoCue photometer.&#x0D; Results: Results showed no significant changes in plasma haemoglogin from day 1, 5, and 10, while significant increase in haemolysis occurred from day 15, 20, 25, 30, and 35 (p = 0.000), a significant increase (p&lt;0.05) in plasma haemoglobin was observed from day 15 to day 35 of storage.&#x0D; Conclusion: It is pertinent therefore to note that the use of CPDA-1 does not completely stop the changes that occur in RBC as there are several changes occurring in stored blood collectively called “storage lesions”. Therefore, it is advisable that blood should be transfused within 14 days of storage to avoid transfusion of blood products that has lost most of its benefits to recipients, and where possible whole blood should be processed and components separated before storage to reduce the level of non-viable red blood cells.

L-Carnitine Supplementation During Hepatitis C Virus Treatment with Sofosbuvir/Daclatasvir Plus Ribavirin: Effect on Anemia: A Pilot Study

AbstractBackground: In the direct acting antiviral era, the role of ribavirin (RBV) in the treatment of hepatitis c virus (HCV) remains crucial, especially in patients with liver cirrhosis and treatment experienced patients. L-carnitine was reported to improve anemia in patients with HCV treated with interferon alone or with ribavirin.Aim of Study: To evaluate the effect of L-carnitine on improving ribavirin induced hemolytic anemia in patients with HCV treated with sofosbuvir/daclatasvir plus ribavirin (SOF/DCV/ RBV).Patients and Methods: Naive patients with HCV related liver cirrhosis and treatment experienced patients who received prior interferon therapy were randomized to receive either SOF/DCV/RBV plus L-carnitine (n=49) or SOF/DCV/RBV (n=49) for 12 weeks as a control group. Changes in hemoglobin concentration, reduction of ribavirin dose and its effect on sustained virological response (SVR) were evaluated.Results: After 4 and 12 weeks of treatment, the hemoglobin concentration was significantly higher in the L-carnitine group than in the control group (p<0.001). RBV dose was reduced in 10.2% of patients in the L-carnitine group versus 22.5% in the control group. The adherence of patients to their ribavirin dose was higher in patients treated with L-carnitine than patients in the control group (89.8% vs. 77.5%). SVR12 rate in the L-carnitine group was higher than that in the control group (93.9%% vs. 87.8%).Conclusion: L-carnitine is effective in improving hemo-lytic anemia induced by ribavirin in patients treated for hepatitis C virus and increase patient's adherence to treatment that guarantees the best opportunity to achieve an SVR.

Accuracy and trending ability of hemoglobin measurement by the Pulse CO-Oximeter during vascular surgery.

Real time information of Hb concentration can guide a tailored patient blood management. The study investigates the accuracy, precision and trending ability of the Pulse CO-Oximeter (SpHb) and blood gas analyzer in measuring the Hb concentration, compared to hematological analysis, in surgery at high risk of hemorrhage. We performed an observational study, involving 48 patients undergoing abdominal aortic open surgery. The primary endpoints of the study were to compare the accuracy in measuring the Hb concentration using non-invasive method (Masimo rainbow SET® Radical 7 Pulse CO-Oximetry™) compared to the values provided by invasive conventional blood gas analyzer and hematological analysis. The secondary endpoint was to compare the differences between the baseline and the final value of the Hb after surgery (Δ-values), as well as the trending ability. Bias (precision) for the SpHb was 1.63g/dL (± 0.05) with 95% limits of agreement between 0.85 and + 2.4g/dL, while for the blood gas analyzer was 0.69g/dL (± 0.04) with 95% limits of agreement between 0.07 and 1.3g/dL. Δ-values values were not statistically different from the reference values of ΔHb obtained with the hematological analysis. Trending ability was good for both Pulse CO-Oximeter and blood gas analysis. Our results have shown that the SpHb is not precise enough to replace an invasive approach, but the trending ability of SpHb is accurate and may provide important information on the changes in hemoglobin concentration to guide blood management.

Monitoring the Depth of Anesthesia Through the Use of Cerebral Hemodynamic Measurements Based on Sample Entropy Algorithm.

The aim of this study is to explore the relationship between the depth of anesthesia and the cerebral hemodynamic variables during the complete anesthesia process. In this study, near-infrared spectroscopy signals were used to record eight kinds of cerebral hemodynamic variables, including left, right, proximal, distal deoxygenated (Hb) and oxygenated (HbO2) hemoglobin concentration changes. Then, by measuring the complexity information of cerebral hemodynamic variables, the sample entropy was calculated as a new index of monitoring the depth of anesthesia. By means of receiver operating characteristic curve analysis, the sample entropy approach was proved to effectively discriminate anesthesia maintenance and waking phases. The discriminatory ability of HbO2 signals was stronger than that of Hb signals and the distal signals had weaker discrimination capability when compared with the proximal signals. In addition, there was statistical consistency between the bispectral index and sample entropy of cerebral hemodynamic variables during the complete anesthesia process. Moreover, the cerebral hemodynamic signals could not be interfered by clinical electrical devices. The sample entropy of cerebral hemodynamic variables could be suitable as a new index for monitoring the depth of anesthesia. This study is very meaningful for developing new modality and decoding methods in perspective of anesthesia surveillance and may result in the anesthesia monitoring system with high performance.

Relationship Between Hepcidin, Interluken-6, And Ferritin In Division-I Cross-country Runners Over A Competitive Season

Iron deficiency, which can be assessed by the iron storage protein ferritin (fer) can negatively affect athletic performance. We have previously observed that Division 1 cross country (XC) runners have fer levels that are at the low end of normal ranges despite being iron supplemented. The hormone hepcidin and the cytokine/myokine interleukin-6 (IL6) can both influence iron regulation but have not been evaluated in this population. PURPOSE: The purpose of this study was to determine how hepcidin and IL6 change over a season in DI XC runners and determine whether changes in these parameters were related to changes in fer, hemoglobin concentration (Hb) or hematocrit (Hct). METHODS: 45 athletes (25 female, 20 male) were recruited from the University of Colorado DI XC team in the fall of 2017. Fasted blood samples were collected in October (before NCAA XC championships), January, and March (during the outdoor track season). Blood samples were analyzed for Hb, Hct, fer, IL6 and hepcidin. All runners were provided with oral iron supplements from a certified nutritionist during this period. RESULTS: All biomarkers remained stable across the season except Hb, which was significantly higher in March. In males vs. females, there were no differences in hepcidin (24 ± 11 vs. 21 ± 11 ng/ml; p > 0.05) or IL6 (16 ± 21 vs. 12 ± 24 pg/mL; p > 0.05). When compared to females, males had higher fer (64 ± 33 vs 47 ± 24 ng/mL; p < 0.05), Hct (48 ± 2 vs 44 ± 3 %; p < 0.001), and Hb (16.3 ± 0.7 vs 14.8 ± 0.8 g/dl; p < 0.01). After controlling for sex, there was a positive relationship between hepcidin and fer (r = 0.47, p < 0.01); 20% of the variability in fer was explained by hepcidin and 51% was explained by individual variability. There were no relationships between IL6 and hepcidin or IL6 and fer. CONCLUSION: Despite a consistent iron supplementation regime, hepcidin, IL6 and fer do not seem to systematically change across a season in collegiate runners. As expected, hepcidin and fer were positively related, but there were no relationships between IL6 and other measured parameters. Although fer was at the low end of normal for both men and women, all other parameters were normal at all time points, suggesting that the normal range of fer for endurance athletes may be lower than the general population.

Perfusion Changes at the Forehead Measured by Photoplethysmography during a Head-Down Tilt Protocol.

Photoplethysmography (PPG) signals from the forehead can be used in pulse oximetry as they are less affected by vasoconstriction compared to fingers. However, the increase in venous blood caused by the positioning of the patient can deteriorate the signals and cause erroneous estimations of the arterial oxygen saturation. To date, there is no method to measure this venous presence under the PPG sensor. This study investigates the feasibility of using PPG signals from the forehead in an effort to estimate relative changes in haemoglobin concentrations that could reveal these posture-induced changes. Two identical reflectance PPG sensors were placed on two different positions on the forehead (above the eyebrow and on top of a large vein) in 16 healthy volunteers during a head-down tilt protocol. Relative changes in oxygenated (HbO), reduced (HHb) and total (tHb) haemoglobin were estimated from the PPG signals and the trends were compared with reference Near Infrared Spectroscopy (NIRS) measurements. Also, the signals from the two PPG sensors were analysed in order to reveal any difference due to the positioning of the sensor. HbO, HHb and tHb estimated from the forehead PPGs trended well with the same parameters from the reference NIRS. However, placing the sensor over a large vasculature reduces trending against NIRS, introduces biases as well as increases the variability of the changes in HHb. Forehead PPG signals can be used to measure perfusion changes to reveal venous pooling induced by the positioning of the subject. Placing the sensor above the eyebrow and away from large vasculature avoids biases and large variability in the measurements.