Total Hemoglobin Measurement Research Articles

Analytical Validation of Two Point-of-Care Assays for Hematological Analysis in the Miranda Donkey.

Miranda donkeys are an endangered autochthonous breed of Portugal. The HemoCue WBC DIFF and HemoCue Hb 201 portable analyzers, developed as a simplified alternative method for total and differential WBC count and hemoglobin measurement, respectively, may be relevant tools in veterinary practice. This study aimed to validate these instruments using Miranda donkey blood samples. For the HemoCue WBC DIFF, most parameters showed acceptable intra- and inter-assay precision with coefficients of variation (CV) below 5%, except for monocytes and eosinophils with higher CVs. The HemoCue Hb 201 showed CVs of 1.98% and 4.07%. Linearity correlation coefficients (r) ranged from 0.53 to 0.99 for HemoCue WBC DIFF and 0.99 for HemoCue Hb 201. Significant levels for neutrophils, lymphocytes, monocytes, eosinophils, and Hb measurements varied. Comparisons with ProCyte Dx showed an excellent correlation for WBC (rs = 0.96), neutrophils (rs = 0.91), lymphocytes (rs = 0.94), and eosinophils (rs = 0.90) but a poor correlation for monocytes and basophils. The HemoCue Hb 201 showed a correlation of rs = 0.96 with ProCyte Dx. In conclusion, both analyzers provided reliable results and are suitable for use in Miranda's donkey breed for WBC counts and Hb measurements.

Reliability of Continuous Noninvasive Hemoglobin Monitoring in Healthy Participants During En Route Care Training.

Current standards for hemoglobin monitoring during air transports of U.S. combat wounded are invasive and intermittent. Fielded pulse co-oximeters can noninvasively measure total hemoglobin, but this parameter is not currently utilized. The primary objective of this study was to assess the percentage of vital sign measurements with successful capture of total noninvasive hemoglobin measurement using spectrophotometry-based technology for Hb (SpHb) measurements in healthy participants during training flights. Secondary objectives were to assess the feasibility of a novel electronic data capture mechanism from usual patient movement items and perform a pilot analysis of SpHb changes in healthy participants during transitions from ground to air transport. We conducted a feasibility study enrolling healthy participants who had hemodynamic monitoring during usual U.S. Air Force Critical Care Air Transport (CCAT) flight training exercises from 2022 to 2023. Usual CCAT monitoring equipment and currently used Masimo Rainbow® pulse co-oximeters had the capability to measure SpHb. After each training exercise, the study team wirelessly downloaded case files from patient monitors utilizing the Battlefield Assisted Trauma Distributed Observation Kit (BATDOKTM) Case Downloader application. We then calculated point and precision estimates for the percentage of time for successful SpHb capture during the exercise and compared this to pulse oximetry (SpO2) capture. An a priori precision analysis for percentage of flight-time with successful SpHb data capture and descriptive statistics were performed. This study received Exempt Determination by the 59th Medical Wing IRB. We analyzed 26 records with mean monitoring durations of 94.5 [59.3-119.9] minutes during ground phases and 78.0 [59.9-106.5] minutes during flight phases. SpHb measures were successfully captured for 97.7% (n = 4,620) of possible ground measurements and 97.2% (n = 3,973) of possible in-flight measurements compared to 99.5% ground and 98.2% in-flight capture for SpO2. Mean intervals of missing SpHb data were 2 ± 5 minutes on the ground and 4 ± 6 minutes in-flight. Mean SpHb increased by 0.93 ± 0.96 g/dL during the ground phase, but had minimal changes during ascent, cruising altitude or descent. The BATDOKTM Case downloader completed transfer for all files. Masimo Rainbow® SpHb pulse co-oximeters reliably captured continuous, noninvasive hemoglobin measurements using usual CCAT patient movement items in healthy participants during both ground and flight training. The BATDOKTM Case Downloader successfully imported case files from CCAT patient monitors. Mean SpHb measures had a small increase during the ground phase of monitoring followed by minimal changes when transitioning to flight altitude.

Interference of bovine hemoglobin-based oxygen carrier-201 (Hemopure) on four hematology analyzers.

Hemoglobin-based oxygen carriers, for example HBOC-201 (Hemopure), are aimed to bridge acute anemia when blood transfusion is not available or refused by the patient. However, since HBOC-201 appears free in plasma, it interferes with laboratory tests. This study presents an overview of HBOC-201 interference on four commonly used hematology analyzers and suggests treatment monitoring possibilities. Blood samples were spiked with therapeutic doses of HBOC-201 and nine hematology parameters were measured with the Sysmex XN-20, Siemens Advia 2120i, Abbott Alinity Hq and Abbot Cell Dyn Sapphire hematology analyzers. The results were compared to control samples and the bias was determined. Most parameters, including all cell counts, hematocrit and MCV, showed a non-significant bias compared to control. However, the standard, total hemoglobin (Hb) measurement as well as MCH and MCHC showed poor agreement with control, as HBOC-201 was included in this measurement. Yet, the flow cytometry-based Hb method quantified intracellular Hb in spiked samples, excluding HBOC-201. Of all included hematology parameters, only total Hb and the associated MCH and MCHC suffered from interference. In contrast, the flow cytometry-based Hb measurement provided an accurate measure of intracellular Hb. The difference between total Hb and cellular Hb represents the HBOC-201 concentration and can be used to monitor HBOC-201 treatment.

Everything About Pulse Oximetry-Part 2: Clinical Applications, Portable/Wearable Pulse Oximeters, Remote Patient Monitoring, and Recent Advances.

Purpose: Pulse oximetry is widely used in healthcare settings for both screening and continuous monitoring. In this article, it was aimed to review some aspects of pulse oximetry including clinical applications, portable devices, and recent advances in detail. Materials and Methods: The international and national reliable sources were used in the literature review for critical data analysis. A total of 31 articles including 19 prospective comparative clinical studies, 9 reviews, 1 meta-analysis, 1 retrospective study, and 1 experimental study were used for preparation of this part of the review. Results: In this part of the article, clinical applications of pulse oximeters, portable/wearable pulse oximeters, remote patient monitoring, and recent advances were all reviewed in detail. Conclusion: Pulse oximetry is a widely used and reliable noninvasive technique that provides useful information about blood oxygenation in individuals. This technique can guide oxygen therapy, reduce the occurrence of hypoxemia, and decrease the frequency of admissions to the intensive care unit, as well as arterial blood gas sampling. New multiwaveform sensors and advanced signal processing techniques can differentiate between different types of hemoglobin and may be useful for continuous measurement of total hemoglobin, as well as for detecting and providing information on blood loss and cardiac output.

Effects of different blood flow restriction pressure levels on muscular hemodynamics

Introduction: Resistance exercise with blood flow restriction (BFR) is an effective method to promote muscle strength gains and hypertrophy. However, little is known about the effects of different BFR levels on hemodynamic responses. Objective: To verify whether the different blood flow restriction pressures applied to the upper limb cause acute changes in vascular microcirculation in young, healthy male adults. Methods: Ten young male visited the laboratory on four occasions. In the first visit, after 10-min rest in supine position, the brachial artery occlusion pressure (AOP) was identified with a Doppler ultrasound. Thereafter, the participants were submitted to a protocol consisting of 1 min for baseline measurements, 2 min of BFR, and 2 min after cuff deflation. It was used a cuff placed on the proximal portion of the forearm and inflated with pressures equivalents to 30% (30BFR), 50% (50BFR) 80% (80BFR), or 100% (100BFR) of the AOP in a random order in separate days. Measurements of tissue saturation index (TSI), oxyhemoglobin, deoxyhemoglobin, and total hemoglobin were collected continuously using near-infrared spectrometry. Results: A two-way ANOVA with repeated measures demonstrated: 1) a significant decrease in TSI in all conditions, with higher decay in 100BFR; 2) a significant increase in oxyhemoglobin in all conditions, but 100BFR; 3) a similar increase in deoxyhemoglobin in all conditions; 4) a significant increase in total hemoglobin in all conditions, mainly in both 30BFR and 50BFR. Conclusion: The relative pressures adopted demonstrated that the hemodynamic changes do not occur linearly with the pressure level imposed by the inflated cuff.

Blood-gas vs. Central-Laboratory analyzers: interchangeability and reference intervals for sodium, potassium, glucose, lactate and hemoglobin

BackgroundBlood-Gas Analyzers (BGAs) are commonly used in parallel with central laboratory analyzers (CLAs). Given the often-divergent results between BGAs and CLAs this study aims to: 1. Determine whether the measurements of potassium (K), sodium (Na), glucose (Glu), lactate (Lact) and total hemoglobin (ctHb) on BGAs and CLAs are interchangeable; 2. Establish reference intervals (RIs) for both analyzer systems using an indirect statistical approach. MethodsDuring a one-year study period K, Na, Glu, Lact and ctHb measurements from 500 arterial blood samples, measured on ABL 90 FLEX BGAs were compared with corresponding venous samples measured on Roche c8000 and Sysmex XN-9000 analyzers. Interchangeability of methods was tested based on the Acceptable Change Limit, Total Change Limit and the guidelines published by the German Medical Association for quality assurance in medical laboratories criteria. Indirect RIs were estimated based on all routine analysis data using the software Reference Limit Estimator (RLE). ResultsWith the exception of Na, the BGAs differed significantly from the CLAs for the tested analytes (P < 0.001) but, with the exception of ctHb, did meet the interchangeability criteria. For K, Na, Gluc and ctHb the reference intervals obtained with RLE did not differ statistically between the analyzer systems. ConclusionThe interchangeability criteria were met for Na, K and Gluc and Lact. The indirect RIs obtained with RLE, are comparable between two systems for Na, K, Gluc an ctHb. Lact differed significantly in the lower reference limit between the BGAs and CLAs. The simultaneous use of both analyzing systems is thus only advisable for Na, K and Gluc.

How to accredit bedside total hemoglobin measurement with the HemoCue® point-of-care device?

HemoCue® point-of care devices are widely used in Bordeaux university hospital center to assess hemoglobin in critical situations, with 45devices in 13health units. Based on our experience, we here propose essential steps in order to prepare the accreditation file. We develop risks analysis, mandatory validation method check points, and caregiver professional training. Among the tasks, precise reference quality instructions i.e. instruction for use, maintenance and troubleshooting should be available. We also share reflections to offer solutions to encountered difficulties. The implemented quality management must rely on a solid and involved laboratory organization. A strong caregiver membership also appears to be the key to move forward.

Monitoring Gas Exchange

Critical illness can threaten the adequacy of O2 delivery or CO2 excretion. Monitoring seeks to identify the adequacy of oxygenation and ventilation and to detect deterioration early. Advances in oximetry, capnography, and transcutaneous CO2 monitoring offer new opportunities for more accurate estimation of gas exchange, noninvasive monitoring of parameters previously not amenable (eg, total hemoglobin measurement), detection of disease, and prediction of fluid responsiveness.

Integrated Anemia Detection and Hemoglobin Variant Identification Using Point-of-Care Microchip Electrophoresis

Introduction: Anemia affects over 2 billion people, which accounts for one-third of the world's population. Anemia causes numerous symptoms including weakness, fatigue, and dizziness as well as life-threatening cardiovascular collapse in severe cases. Primary hemoglobinopathies, including Sickle Cell Disease (SCD) and Thalassemia are the most common causes of anemia after iron deficiency and hookworm disease. Anemia induced by SCD and Thalassemia may potentially induce severe and chronic results thus both diseases require consistent monitoring. Optimal management of anemia and SCD specifically requires early diagnosis and consistent monitoring using blood tests that measure hemoglobin level and phenotype. Clinical hydroxyurea therapy in patients with SCD has been well established worldwide and an increase in hemoglobin level has been identified as an important clinical endpoint in assessing therapeutic efficacy. In a 2019 report, the World Health Organization (WHO) has listed hemoglobin testing as one of the most essential in vitro diagnostic (IVD) tests for primary care use in low and middle income countries. Furthermore, hemoglobin electrophoresis has recently been added to the WHO essential list of IVDs for diagnosing SCD and sickle cell trait. The current gold standard for anemia testing and hemoglobin level measurement is complete blood count (CBC) using a hematology analyzer. The current gold standard for hemoglobin variant identification is High Performance Liquid Chromatography (HPLC). Both tests require state-of-the-art laboratory infrastructure and highly trained personnel, which are typically scarce or non-existent in low- and middle-income countries, where anemia and hemoglobinopathies are most prevalent. As a result, there is a critical need for portable accurate affordable point-of-care tools for anemia detection and hemoglobin variant identification. Here, were present HemeChip+, a POC microchip electrophoresis technology for integrated anemia detection and hemoglobin variant identification in resource limited settings. Methods: HemeChip+ works with a finger or heel prick blood sample. HemeChip+ test is embodied in a mass-producible fully integrated microchip electrophoresis cartridge (Fig. 1A-D). Integrated test is a two step process. Step 1 is the separation of the total hemoglobin (red) and the standard calibrator (blue), which takes place within 3 minutes of test start (Fig. 1E). This separation takes place due to the mass-to-charge ratio between hemoglobin and standard calibrator which were mixed at a fixed ratio. Total hemoglobin level is quantified by comparing hemoglobin band color intensity and the standard calibrator color intensity. Step 2 is the separation of hemoglobin variants (Fig. 1E), which takes place between 3 - 8 minutes after test start. In this step, individual hemoglobin sub-types separate according to their mass-to-charge ratio (Fig. 1E&amp;1F). HemeChip+ platform has been developed based on extensively validated HemeChip microchip electrophoresis technology, which is currently being commercialized under product name "Gazelle" by Hemex Health Inc. for POC hemoglobin testing in low and middle income countries (Fig. 1G). Results and Discussion: Feasibility of integrated total hemoglobin detection and hemoglobin variant identification was tested using blood samples from 10 donors with hemoglobin levels that ranged from 6.2 to 13.2 g/dL and various hemoglobin variants including normal (Hb AA), sickle trait (Hb AS), sickle cell disease (Hb SS), sickle hemoglobin C disease (Hb SC). HemeChip+ total hemoglobin measurement results were compared with clinical standard CBC tests. The results showed a Pearson correlation coefficient (PCC) of 0.95 (p&amp;lt;0.001) between HemeChip+ measurement and standard CBC (Fig. 1H). HemeChip+ hemoglobin variant identification results were compared with clinical standard HPLC results demonstrating 100% accuracy (N=10, Fig. 1I). HemeChip+ satisfactorily performed integrated anemia detection and hemoglobin variant identification in this study. HemeChip+ technology offers an original and innovative solution to integrated POC testing for anemia and hemoglobin disorders within the same platform. Disclosures An: Hemex Health, Inc: Consultancy, Equity Ownership, Patents &amp; Royalties. Hasan:Hemex Health, Inc.: Equity Ownership, Patents &amp; Royalties. Gurkan:Hemex Health, Inc.: Consultancy, Employment, Equity Ownership, Patents &amp; Royalties, Research Funding.

Validity of accuracy and trending ability of non-invasive continuous total hemoglobin measurement in complex spine surgery: a prospective cohort study

BackgroundPatients undergoing complex spine surgery present with multilevel spinal involvement, advanced age, and multiple comorbidities. Surgery is associated with significant blood loss and remarkable hemodynamic changes. The present study aimed to investigate the accuracy and trending ability of a non-invasive continuous method to monitor hemoglobin (SpHb) concentrations using a Radical-7™ Pulse CO-Oximeter in complex spine surgery.MethodsForty-nine patients who underwent complex spine surgery were enrolled in this prospective observational study. Multiple time points were established for data collection throughout the operation. Simultaneous SpHb–total hemoglobin (tHb) paired data were recorded for analyses. Linear regression analysis, Bland–Altman plot, four-quadrant plot, and Critchley polar plot were used to assess the accuracy and trending ability of the monitor.ResultsA total of 272 pairs of SpHb-tHb data were available and were divided into two groups based on the perfusion index (PI): PI values ≥1.0 (n = 200) and PI values < 1.0 (n = 72). The correction coefficients (r) between SpHb and tHb were 0.6946 and 0.6861 in the groups with PI values ≥1.0 and < 1.0, respectively (P < 0000.1). In the ≥1.0 group, the mean bias was − 0.21 g/dL and the percentage error (PE) was 15.85%, whereas in the < 1.0 group, the mean bias was − 0.04 g/dL and the PE was 17.42%. Four-quadrant plot revealed a concordance rate of 85.11%, whereas the Critchley polar plot showed a concordance rate of 67.21%.ConclusionsThe present study demonstrates the acceptable accuracy of the Radical-7™ Pulse CO-Oximeter even with a low PI. However, the trending ability was limited and unsatisfactory.

Host sex, size, and hemoparasite infection influence the effects of ectoparasitic burdens on free-ranging iguanas.

Investigations focusing on host–ectoparasite interactions in animals have revealed asymptomatic to severe health and fitness consequences suggesting that species mobilize different interspecific response mechanisms. Fewer studies, however, have examined intraspecific responses to ectoparasitic burdens. In this study, we analyzed host health and fitness responses to increasing ectoparasite burdens along with the presence/absence of hemoparasites of free‐ranging insular rock iguanas (Cyclura cychlura) in The Bahamas. Using hematology, plasma biochemistry, as well as body condition and growth rate comparisons, we failed to find significant associations of tick burdens with annual growth rate, corticosterone, packed cell volume, total white blood cell, and heterophil, monocyte, eosinophil or hemoglobin measures. We did, however, find mixed and significant associations of tick burdens with lymphocyte and basophil counts, heterophil‐to‐lymphocyte ratios, and body condition indices. These associations varied by sex, size, and hemoparasite infection status suggesting that different life stages of iguanas may invest differently in immune responses, and impacts may be modulated based on size and sex of hosts, and coinfection status.

Reliability of Wearable Two Channel CW-NIRS in Measurements of Brain Function.

Multi-channel NIRS, so-called optical topography (OT), allows functional mapping of the cortex; however, it takes a long time to set optodes on the head and is relatively expensive. Thus, OT is not suitable as a screening test of brain disorders evaluating many subjects. Recently, a wearable two-channel continuous wave NIRS (CW-NIRS) device has been developed. Such a simple NIRS device may be applicable as a screening test of brain disorders; however, its reliability in measurements of brain function is not yet clear. Here, we tested a two-channel CW-NIRS, which employs single LED (800nm) for measurement of total hemoglobin (t-Hb) changes. We measured t-Hb changes in the bilateral prefrontal cortex (PFC) during mental arithmetic tasks, employing the CW-NIRS and time-resolve NIRS (TNIRS). The left-right asymmetry of the PFC activity was evaluated by calculating the laterality index (LI; (R-L)/(R + L) of t-Hb), which reflects mental stress. The interval between CW-NIRS and TNIRS measurements was 1-13days. A significant positive correlation was observed between LI measured by CW-NIRS and TNIRS. These results suggest the reliability of the simple CW-NIRS, and it may be applicable to prevent stress-induced various diseases. Finally, it should be emphasized that the left-right asymmetry of PFC activity is relatively stable.

Impact of shear rate pattern on post-occlusive near-infrared spectroscopy microvascular reactivity

The primary aim of the present study was to determine the impact of acute changes in shear rate patterns, in particular retrograde shear rate, on microvascular function in 15 healthy, young men and women as determined via the post-occlusive near-infrared spectroscopy (NIRS) microvascular reactivity response. Microvascular reactivity, via NIRS-derived measurements of post-occlusion tissue saturation index (TSI%) and total microvascular hemoglobin+myoglobin concentration ([Hb]total), were assessed in each participant before and immediately after exposure to a 30min retrograde shear treatment. Retrograde shear was achieved via a blood pressure cuff placed below the knee inflated to 75mmHg. One leg was exposed to the retrograde shear (Treatment leg) and the contralateral leg served as a non-treatment control. In the Treatment leg, significant increases in retrograde shear rate occurred during the retrograde intervention. Following the intervention, the area under the TSI% post-occlusion response curve, which represents the total microvascular reactivity response, and the absolute peak TSI% response were significantly increased compared to pre-intervention in the Treatment leg, but not the Control leg. The absolute peak [Hb]total response was significantly increased post-intervention in both legs. These results are in contrast to our hypothesis that 75mmHg cuff inflation, designed to increase retrograde shear rate in the femoral artery would negatively affect post-occlusive microvascular reactivity. These data suggest that the current method of increasing retrograde shear rate in the intact human does not adversely impact NIRS derived measurements of microvascular reactivity.

Reproducibility of measurement of skin melanin, total hemoglobin, and oxygen saturation

Skin Research and TechnologyVolume 24, Issue 1 p. 158-159 LETTER TO THE EDITOR Reproducibility of measurement of skin melanin, total hemoglobin, and oxygen saturation Theodore G. Papaioannou, Corresponding Author Theodore G. Papaioannou [email protected] orcid.org/0000-0002-1552-3168 Biomedical Engineering Unit and Biostatistics Unit, First Department of Cardiology, Medical School, National and Kapodistrian University of Athens, Athens, Greece Correspondence Theodore G. Papaioannou, First University Department of Cardiology Hippokration Hospital, Athens, Greece. Email: [email protected]Search for more papers by this authorMarianna Karamanou, Marianna Karamanou Biomedical Research Foundation of the Academy of Athens, Athens, GreeceSearch for more papers by this authorDimitrios Tousoulis, Dimitrios Tousoulis Biomedical Engineering Unit and Biostatistics Unit, First Department of Cardiology, Medical School, National and Kapodistrian University of Athens, Athens, GreeceSearch for more papers by this author Theodore G. Papaioannou, Corresponding Author Theodore G. Papaioannou [email protected] orcid.org/0000-0002-1552-3168 Biomedical Engineering Unit and Biostatistics Unit, First Department of Cardiology, Medical School, National and Kapodistrian University of Athens, Athens, Greece Correspondence Theodore G. Papaioannou, First University Department of Cardiology Hippokration Hospital, Athens, Greece. Email: [email protected]Search for more papers by this authorMarianna Karamanou, Marianna Karamanou Biomedical Research Foundation of the Academy of Athens, Athens, GreeceSearch for more papers by this authorDimitrios Tousoulis, Dimitrios Tousoulis Biomedical Engineering Unit and Biostatistics Unit, First Department of Cardiology, Medical School, National and Kapodistrian University of Athens, Athens, GreeceSearch for more papers by this author First published: 23 October 2017 https://doi.org/10.1111/srt.12408Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL No abstract is available for this article. Volume24, Issue1February 2018Pages 158-159 RelatedInformation

Efficacy of Pulse Co-oximeter in Hemoglobin Estimation: A non invasive method

Background: Total Hemoglobin(Hb) measurement is one of the most common and important parameter that is investigated in the laboratory.This non invasive method allows pain free continuous online patient monitoring with minimum risk of infection and facilitates real time data monitoring allowing immediate clinical reaction to the measured data. The objective of the study is to test the efficacy of pulse co-oximeter .Methods: Present study is a prospective descriptive study. A total of 261 patients enrolled for the study after their consent. Non invasively measured SpHb values and invasively measured Hb values were then compared by using Bland Altman statistical analysis . Result: Pulse co-oximeter recorded/displayed SpHb in 90.8% patients and did not display SpHb in 9.2% of patients. Out of which 73-75% patients Hb showed variation of less than or equal to 2gms and 20-24% patients Hb showed variation of more than 2 gms. On Bland Altmann comparative analysis of SpHb and Hb revealed bias and limits of agreement was 0.2+3.3gm/d and 95% of the measurements fell within two standard deviation of the mean difference and P value < 0.001 represents good correlation between SpHb and Hb of Lab1 and Lab 2.Conclusion: Pulse co-oximeter can be used as a screening tool for Hb measurement at out patient departments, blood camps, casuality, ICU and labor rooms. It determines Hb instantly and non invasively. Further studies are needed to determine financial aspects and needs upgradation in terms of accuracy of the instrumentDOI:10.21276/APALM.1558

Measurement of total hemoglobin reduces red cell transfusion in hospitalized patients undergoing cardiac surgery: a retrospective database analysis.

Introduction:Historically, perioperative hemoglobin monitoring has relied on calculated saturation, using blood gas devices that measure plasma hematocrit (Hct). Co-oximetry, which measures total hemoglobin (tHb), yields a more comprehensive assessment of hemodilution. The purpose of this study was to examine the association of tHb measurement by co-oximetry and Hct, using conductivity with red blood cell (RBC) transfusion, length of stay (LOS) and inpatient costs in patients having major cardiac surgery.Methods:A retrospective study was conducted on patients who underwent coronary artery bypass graft (CABG) and/or valve replacement (VR) procedures from January 2014 to June 2016, using MedAssets discharge data. The patient population was sub-divided by the measurement modality (tHb and Hct), using detailed billing records and Current Procedural Terminology coding. Cost was calculated using hospital-specific cost-to-charge ratios. Multivariable logistic regression was performed to identify significant drivers of RBC transfusion and resource utilization.Results:The study population included 18,169 cardiovascular surgery patients. Hct-monitored patients accounted for 66% of the population and were more likely to have dual CABG and VR procedures (10.4% vs 8.9%, p=0.0069). After controlling for patient and hospital characteristics, as well as patient comorbidities, Hct-monitored patients had significantly higher RBC transfusion risk (OR=1.26, CI 1.15-1.38, p<0.0001), longer LOS (IRR=1.08, p<0.0001) and higher costs (IRR=1.15, p<0.0001) than tHb-monitored patients. RBC transfusions were a significant driver of LOS (IRR=1.25, p<0.0001) and cost (IRR=1.22, p<0.0001).Conclusions:tHb monitoring during cardiovascular surgery could offer a significant reduction in RBC transfusion, length of stay and hospital cost compared to Hct monitoring.

Oxygen Utilization During The Contraction-Relaxation Cycle Of Intermittent Forearm Exercise

Previous work from our laboratory showed that microvascular RBC volume was preserved and extraction of O2 continued to occur during the contraction phase of intermittent leg extension exercise. Limitations of these measures in the quadriceps include adipose tissue thickness and an inability to observe more than the most superficial portions of the muscle. The smaller muscle mass of the forearm is advantageous in that it possesses a smaller adipose pad and allows for a more comprehensive interrogation of the entire muscle. PURPOSE: The purpose of the current study was to characterize muscle oxygenation during the contraction/relaxation phases of intermittent forearm exercise. We hypothesized that O2 extraction by the muscle would not be limited to the relaxation phase of exercise. METHODS: Six healthy men (24 ± 2 yrs) completed two constant-power handgrip exercise tests at moderate (M: 40% peak power) and severe (S: 85% peak power) intensities for 10 minutes or until exhaustion. Using near-infrared spectroscopy (NIRS), measurements of total hemoglobin and myoglobin (total [Hb+Mb]), deoxygenated hemoglobin and myoglobin (deoxy [Hb+Mb]) and tissue O2 saturation (StO2) of the flexor digitorum superficialis were taken to determine changes in microvascular hematocrit, estimated microvascular O2 extraction and tissue oxygenation, respectively. Mean values for the relaxation phase and peak values during the contraction phase were calculated at both intensities. RESULTS: Total [Hb+Mb] (M: 103 ± 18.2 μM; S: 119 ± 26.9 μM) and deoxy [Hb+Mb] (M: 44.4 ± 17.9 μM; S: 53.7 ± 13.5 μM) were higher (P < 0.05) during severe intensity exercise compared to moderate intensity exercise. Regardless of intensity, the contraction phase elicited an increase (P < 0.05) in total [Hb+Mb] (M: 6.33 ± 3.88 μM; S: 7.59 ± 6.64 μM) as well as in StO2 (M: 3.69 ± 1.49 %; S: 5.31 ± 4.52 %;P = 0.01). In addition, deoxy [Hb+Mb] (M: 5.79 ± 8.75 μM; S: 7.99 ± 7.81 μM) tended to be greater (P = 0.08) during the contraction phase for both intensities. CONCLUSION: The increases in total [Hb+Mb] and StO2 during contraction suggest that arterial oxygenated blood may be shifted from larger NIRS-invisible vessels to smaller NIRS-visible ones by the contraction process, which may mask O2 extraction during contraction.

Accuracy of non-invasive continuous total hemoglobin measurement by Pulse CO-Oximetry in severe traumatized and surgical bleeding patients.

The Masimo Radical-7 Pulse CO-Oximeter (Masimo Corp., USA) non-invasively computes hemoglobin concentration (SpHb). SpHb was compared to Co-Oximeter readings (CoOxHb) of arterial samples in surgery patients of the emergency department. Forty-six patients were enrolled. The Masimo R1 25L (revision F and G) adult adhesive sensor was attached to the ring finger of the arterially cannulated hand. Before start, every 30min during surgery and in the case of severe bleeding SpHb and CoOxHb values were documented. SpHb and post hoc adjusted SpHb (AdSpHb) values were analyzed. Linear regression analysis and Bland-Altman plot for agreement were performed. The detection failure rate of SpHb was 24.5%. CoOxHb and SpHb showed a strong correlation (r=+0.81), but agreement was moderate [bias (LOA) of -0.6 (-3.0; +1.9)] g/dl. Positive and negative predicted value was 0.49 and 0.69. Exclusion of changes of CoOxHb values ≤1g/dl resulted in a positive and negative predictive value of 0.66 and 1.00. Post hoc adjustment of the SpHb (AdSpHb) improved linear correlation of CoOxHb and AdSpHb [r=+0.90 (p<0.001)] but less the agreement [bias (LOA) of CoOxHb and AdSpHb=-0.1 (-2.1/+1.9)g/dl]. SpHb agreed only moderately with CoOxHb values and predicted decreases of CoOxHb only if changes of SpHb≤1.0g/dl were excluded. The detection failure rate of SpHb was high. At present, additional refinements of the current technology are necessary to further improve performance of non-invasive hemoglobin measurement in the clinical setting.

Quantitative, single-step dual measurement of hemoglobin A1c and total hemoglobin in human whole blood using a gold sandwich immunochromatographic assay for personalized medicine

We describe a gold nanoparticle-based sandwich immunoassay for the dual detection and measurement of hemoglobin A1c (HbA1c) and total hemoglobin in the whole blood (without pretreatment) in a single step for personalized medicine. The optimized antibody-functionalized gold nanoparticles immunoreact simultaneously with HbA1c and total hemoglobin to form a sandwich at distinctive test lines to transduce visible signals. The applicability of this method as a personal management tool was demonstrated by establishing a calibration curve to relate % HbA1c, a useful value for type 2 diabetes management, to the signal ratio of captured HbA1c to all other forms of hemoglobin. The platform showed excellent selectivity (100%) toward HbA1c at distinctive test lines when challenged with HbA0, glycated HbA0 and HbA2. The reproducibility of the measurement was good (6.02%) owing to the dual measurement of HbA1c and total hemoglobin. A blood sample stability test revealed that the quantitative measurement of % HbA1c was consistent and no false-positive results were detected. Also, this method distinguished the blood sample with elevated HbF from the normal samples and the variants. The findings of this study highlight the potential of a lateral flow immunosensor as a simple, inexpensive, consistent, and convenient strategy for the dual measurement of HbA1c and total Hb to provide useful % HbA1c values for better on-site diabetes care.

Iron metabolism following intravenous transfusion with stored versus fresh autologous erythrocyte concentrate in healthy dogs.

OBJECTIVE To determine effects of IV transfusion with fresh (3-day-old) or stored (35-day-old) autologous erythrocyte concentrate on serum labile iron concentration, iron-binding capacity, and protein interaction with iron in dogs. ANIMALS 10 random-source healthy dogs. PROCEDURES Dogs were randomly assigned to receive autologous erythrocyte concentrate stored for 3 days (n = 5) or 35 days (5). One unit of whole blood was collected from each dog, and erythrocyte concentrates were prepared and stored as assigned. After erythrocyte storage, IV transfusion was performed, with dogs receiving their own erythrocyte concentrate. Blood samples were collected from each dog before and 5, 9, 24, 48, and 72 hours after transfusion. Serum was harvested for measurement of total iron, labile iron, transferrin, ferritin, hemoglobin, and haptoglobin concentrations. RESULTS For dogs that received fresh erythrocytes, serum concentrations of the various analytes largely remained unchanged after transfusion. For dogs that received stored erythrocytes, serum concentrations of total iron, labile iron, hemoglobin, and ferritin increased markedly and serum concentrations of transferrin and haptoglobin decreased after transfusion. CONCLUSIONS AND CLINICAL RELEVANCE Transfusion with autologous erythrocyte concentrate stored for 35 days resulted in evidence of intravascular hemolysis in healthy dogs. The associated marked increases in circulating concentrations of free iron and hemoglobin have the potential to adversely affect transfusion recipients.