HemoCue Hb-801 Provides More Accurate Hemoglobin Assessment in Blood Donors Than OrSense NBM-200.

Hemoglobin levels are commonly assessed to prevent causing or worsening of anemia in prospective blood donors. We compared head-to-head the accuracy of different technologies for measuring hemoglobin suitable for use in mobile donation units. We included 144 persons donating platelets at the Central Institute for Blood Transfusion and Immunology in Innsbruck, Austria. Hemoglobin levels were measured in venous blood using the portable hemoglobinometer HemoCue Hb-801 and noninvasively using OrSense NBM-200, and compared to values obtained with the Sysmex XN-430, an automated hematology analyzer employing the sodium lauryl sulphate method, which is broadly used as reference method in everyday clinical practice. Mean age of participants was 34.2 years (SD 13.0); 34.0% were female. Hemoglobin values measured with HemoCue were more strongly correlated with the Sysmex XN-430 (r = 0.90 [95% CI: 0.87-0.93]) than measured with OrSense (r = 0.49 [0.35-0.60]). On average, HemoCue overestimated hemoglobin by 0.40 g/dL (0.31-0.48) and OrSense by 0.75 g/dL (95% CI: 0.54-0.96). When using OrSense, we found evidence for higher overestimation at higher hemoglobin levels (proportional bias) specifically in females but not in males (Pdifference = .003). Sensitivity and specificity for classifying donors according to the hemoglobin donation thresholds were 99.2% (95% CI: 95.3%-100.0%) and 43.8% (23.1%-66.8%) for HemoCue vs 95.3% (89.9%-98.0%) and 12.5% (2.2%-37.3%) for OrSense. Areas under the receiver operating characteristic curves were higher using HemoCue vs OrSense both in females (0.933 vs 0.547; P = .044) and males (0.948 vs 0.628; P < .001). HemoCue Hb-801 measures hemoglobin more accurately than OrSense NBM-200 in the setting of mobile blood donation units. Our findings are particularly relevant for females, having in mind that anemia is more prevalent in females than in males.

Comparison between a laser lancing device and lancet for capillary blood sampling, capillary blood hemoglobin measurement, and blood typing.

BACKGROUND: Blood donor screening includes tests using capillary blood, which is usually obtained by finger pricking using a lancet; however, the lancet has some shortcomings, such as skin puncture pain and needle stick injury. Recently, laser lancing devices for finger-prick sampling have been developed. We compared capillary blood Hb (cHb) levels and blood typing results obtained using a laser lancing device with those obtained using a lancet. STUDY DESIGN AND METHODS: cHb levels, blood typing results, and skin puncture pain scores were assessed in 191 participants. Finger-prick sampling was performed using LMT-1000 (LaMeditech, Seoul, Korea) and a lancet on the same finger on different hands. Paired venous Hb (vHb) levels were assessed in 103 participants using an automated hematology analyzer and compared with the cHb levels obtained using both lancing devices. RESULTS: The paired cHb results obtained with the laser lancing device and lancet showed a strong correlation (r = 0.927, p < .001) without any significant difference (p = .113) and a substantial agreement (κ = 0.654) for the identification of participants with a low Hb level (<12.5 g/dl). cHb levels were significantly higher than vHb levels with both lancing devices (mean differences: 0.27-0.43 g/dl). The results of blood typing using the laser lancing device showed 100% accuracy. Use of the laser lancing device showed significantly lower skin puncture pain scores (p < .001). CONCLUSION: Use of a laser lancing device for capillary Hb measurement and blood typing showed accurate results, with significantly reduced skin puncture pain. Laser lancing devices could be feasible for donor screening tests.

Non-invasive hemoglobin measurement devices require refinement to match diagnostic performance with their high level of usability and acceptability.

Anemia remains an important global health problem. Inexpensive, accurate, and noninvasive solutions are needed to monitor and evaluate anemia in resource-limited settings. We evaluated the performance of multiple point-of-care hemoglobin devices, including a novel noninvasive smartphone application tested on Apple® and Android® cell phones, Masimo Pronto®, and HemoCue® Hb-301 and Hb-801, against a gold-standard hematology analyzer (reference hemoglobin) using venous blood. We examined correlations between hemoglobin devices and reference hemoglobin, device accuracy (average bias, Bland-Altman plots, clinical performance) and classification bias (sensitivity, specificity) among 299 refugees (10mo-65y) in Atlanta, GA. Semi-structured interviews (n = 19) with participants and staff assessed usability and acceptability. Mean reference hemoglobin was 13.7 g/dL (SD:1.8) with 12.5% anemia. Noninvasive hemoglobin devices were not well correlated with reference hemoglobin (Apple® R2 = 0.08, Android® R2 = 0.11, Masimo Pronto® R2 = 0.29), but stronger correlations were reported with HemoCue® Hb-301 (R2 = 0.87) and Hb-801 (R2 = 0.88). Bias (SD) varied across each device: Apple®: -1.6 g/dL (2.0), Android®: -0.7 g/dL (2.0), Masimo Pronto®: -0.4 g/dL (1.6), HemoCue® Hb-301: +0.4 g/dL (0.7) and HemoCue® Hb-801: +0.2 g/dL (0.6). Clinically acceptable performance (within ± 1 g/dL of reference hemoglobin) was higher for the invasive devices (HemoCue® Hb-301: 90.3%; HemoCue® Hb-801: 93.4%) compared to noninvasive devices (Apple®: 31.5%; Android®: 34.6%; Masimo Pronto®: 49.5%). Sensitivity and specificity were 63.9% and 48.2% for Apple®, 36.1% and 67.6% for Android®, 45.7% and 85.3% for Masimo Pronto®, 54.3% and 97.6% for HemoCue® Hb-301, and 66.7% and 97.6% for HemoCue® Hb-801. Noninvasive devices were considered easy to use and were the preferred method by participants. Among the only studies to compare multiple point-of-care approaches to hemoglobin testing, the diagnostic ability of HemoCue® was comparable to reference hemoglobin, while noninvasive devices had high user acceptability but considerable biases. Improvements in noninvasive device performance and further testing in anemic populations are recommended before broader use.

Hemoglobin point-of-care testing in rural Gambia: Comparing accuracy of HemoCue and Aptus with an automated hematology analyzer.

BACKGROUND: Anemia is one of the most impactful nutrient deficiencies in the world and disproportionately affects children in low-resource settings. Point-of-care devices (PoCDs) measuring blood hemoglobin (Hb) are widely used in such settings to screen for anemia due to their low cost, speed, and convenience. Here we present the first iteration of Aptus, a new PoCD which measures Hb and hematocrit (HCT). AIM: To evaluate the accuracy of Aptus and HemoCue® Hb 301 against an automated hematology analyzer (Medonic®) in Gambian children aged 6-35 months and the Aptus' usage in the field. METHODS: Aptus, HemoCue® and Medonic® were compared using venous blood (n = 180), and Aptus and HemoCue® additionally using capillary blood (n = 506). Agreement was estimated using Bland-Altman analysis and Lin's concordance. Usage was assessed by error occurrence and user experience. RESULTS: Mean Hb values in venous blood did not significantly differ between Aptus and HemoCue® (10.44±1.05 vs 10.56±0.93g/dl, p>0.05), but both measured higher Hb concentrations than Medonic® (9.75±0.99g/dl, p<0.0001). Lin's coefficient between Aptus and Medonic® was rc = 0.548, between HemoCue® and Medonic® rc = 0.636. Mean bias between the PoCDs venous measurements was -0.11g/dl with limits of agreement (LoA) -1.63 and 1.40g/dl. The bias was larger for the comparisons between the Medonic® and both Aptus (0.69g/dl, LoA 0.92 and 2.31g/dl) and HemoCue® (0.81g/dl, LoA 0.17 and 1.78g/dl). ROC curves showed an AUC of 0.933 in HemoCue® and 0.799 in Aptus. Capillary Hb was higher with Aptus than HemoCue® (10.33±1.11g/dl vs 10.01±1.07g/dl, p<0.0001). Mean bias was 0.32g/dl with LoA of -1.91 and 2.54g/dl. Aptus' usage proved intuitive, yet time-to-results and cuvettes could be improved. CONCLUSION: Both PoCDs showed a relatively limited bias but large LoA. Aptus and HemoCue® showed similar accuracy, while both overestimated Hb levels. Aptus showed promise, with its operation unimpaired by field conditions as well as being able to show HCT values.

Validation of Two Point of Care Devices for Hemoglobin Estimation in Blood Donors.

Hemoglobin (Hb) estimation is a critical investigation in prospective blood donors. There are numerous techniques for Hb estimation, choosing an appropriate method is essential. Point of care devices (POC) have made quantification of Hb possible even in the field or community settings. Validation against a standard measure is necessary before implementing it for routine practice. With this background, we aimed to validate two new POC devices against a standard hematology analyzer for Hb estimation. An observational study on 100 donor venous blood samples was conducted. Hemoglobin was estimated using a Sysmex Hematology Analyzer (reference method) along with POC devices (CompoLab TM and True Hb Hemometer). Three statistical techniques were applied to validate Hb by the two POC devices. CompoLab TM measures 0.4 units more than the reference method and True Hb measures 0.4 units less than the reference method. Measures of Hb obtained from both the equipment showed moderate agreement with that of reference method (CompoLab TM ICC-0.74 and True Hb ICC-0.72). There were no systematic or proportional differences in the comparison of the two POC devices with the reference method. Within the limitations of this study, both the devices can be used for Hb estimation, as there was a substantial agreement of the measurements with the reference method. Other factors such as cost, turnaround time (TAT), ease of utilization should be considered to decide on the choice of equipment to be used.

Potential new tool for anemia screening: An evaluation of the performance and usability of the TrueHb Hemometer.

In low- and middle-income countries, many women experience anemia during pregnancy due to insufficient dietary intake of key micronutrients, parasitic infections, hemoglobinopathies, and chronic infections. Maternal anemia increases perinatal risks for both mothers and infants, and slow progress to reduce the prevalence may be due in part to the lack of affordable tools to quantify hemoglobin levels in antenatal care (ANC) clinics. A simple, inexpensive, accurate, and robust diagnostic is needed to measure hemoglobin in ANC. This study evaluated the performance and usability of the TrueHb Hemometer. A cross-sectional diagnostic accuracy study was conducted to compare the accuracy of the TrueHb and the HemoCue® 201+ using capillary samples. Next, analytical performance (precision, coefficient of variation, R2) of the TrueHb was evaluated in varying environmental conditions using linearity panels with serial dilutions of venous blood samples. Lastly, the usability of the TrueHb Hemometer was assessed across three domains (effectiveness, efficiency, and satisfaction) by 20 ANC providers in Ghana. Capillary blood test results were not well correlated (R2 = 0.35) between the TrueHB and HemoCue201+, but 80% of TrueHb measurements were within +/-1.0 g/dl of the HemoCue® 201+ hemoglobin values. Precision tests indicated similar mean values across the three environmental conditions (CV<6%). At 21°C, the TrueHb follows a linear relationship (R2≥0.96) but does not generate accurate readings below 4.0 g/dl. At 30°C and 37°C, the TrueHb follows a linear relationship (R2 > 0.90) but begins to underestimate the hemoglobin concentration below 7.0 g/dl. The usability study identified potential failure modes due to inadequate instructions and device feedback. With some modifications, both to the product and to the instructions for use, the TrueHb may be suitable for use in ANC settings to help fill the diagnostic gap for anemia screening during pregnancy. Further testing is required with anemic populations in LMIC settings.

Methods and analyzers for hemoglobin measurement in clinical laboratories and field settings.

This paper describes and compares methods and analyzers used to measure hemoglobin (Hb) in clinical laboratories and field settings. We conducted a literature review for methods used to measure Hb in clinical laboratories and field settings. We described methods to measure Hb and factors influencing results. Automated hematology analyzer (AHA) was reference for all Hb comparisons using evaluation criteria of ±7% set by College of American Pathologists (CAP) and Clinical Laboratory Improvement Amendments (CLIA). Capillary fingerprick blood usually produces higher Hb concentrations compared with venous blood. Individual drops produced lower concentrations than pooled capillary blood. Compared with the AHA: (1) overall cyanmethemoglobin (1.0-8.0  g/L), WHO Colour Scale (0.5-10.0  g/L), paper-based devices (5.0-7.0  g/L), HemoCue® Hb-201 (1.0-16.0  g/L) and Hb-301 (0.5-6.0  g/L), and Masimo Pronto® (0.3-14.0  g/L) overestimated concentrations; (2) Masimo Radical®-7 both under- and overestimated concentrations (0.3-104.0  g/L); and (3) other methods underestimated concentrations (2.0-16.0  g/L). Most mean concentration comparisons varied less than ±7% of the reference. Hb measurements are influenced by several analytical factors. With few exceptions, mean concentration bias was within ±7%, suggesting acceptable performance. Appropriate, high-quality methods in all settings are necessary to ensure the accuracy of Hb measurements.This paper describes and compares methods and analyzers used to measure hemoglobin (Hb) in clinical laboratories and field settings. With few exceptions, mean concentration bias was within ±7%, suggesting acceptable performance. Appropriate, high-quality methods in all settings are necessary to ensure the accuracy of Hb measurements.

Comparison of visual estimation of intra-operative blood loss with haemoglobin estimation in patients undergoing caesarean section.

BACKGROUND: Obstetrical haemorrhage is a potentially preventable cause of maternal morbidity and mortality; and measurements of surgical blood loss (BL) are often inaccurate. Accurate BL estimation is paramount as it may substantially alter the timing of interventions to control haemorrhage. The study compares the assessment of intra-operative BL by visual estimation with BL calculated from haemoglobin estimation using the HemoCue®201+. MATERIALS AND METHODS: A total of 60 pregnant patients at term undergoing elective caesarean section under spinal anaesthesia were enrolled into the study. In the theatre, the patients' haemoglobin level was determined before and after the surgery using the HemoCue®201+; and a modified Gross formula was used to calculate the BL. BL was also visually estimated and documented by counting the blood-soaked abdominal mops and gauze pieces and multiplying them by the estimated volume of blood each would hold; fixed size mops and gauzes were used. Statistical analysis was performed to compare both methods using SPSS Version 17. To compare BL assessment, Pearson's correlation and the Bland and Altman's method of assessing agreement between two methods of clinical measurement were used. RESULTS: The mean visually estimated BL (EBL) and HemoCue calculated BL (CBL) were 470 ± 221 ml and 563 ± 204 ml, respectively (P = 0.125). The bias (mean difference between both methods) was negligible (45.25 ml), and the limit of agreement between both methods was -222.20-275.43 ml. The discrepancy between the two methods increased when BL was ≥500 ml. CONCLUSION: This study showed that visually EBL was closely related to HemoCue CBL when the quantity of BL was <500 ml.

Measurement and interpretation of hemoglobin concentration in clinical and field settings: a narrative review.

Anemia affects over 800 million women and children globally. Defined as a limited or insufficient functional red blood cell supply in peripheral blood, anemia causes a reduced oxygen supply to tissues and can have serious health consequences for women and children. Hemoglobin (Hb) concentration is most commonly measured for anemia diagnosis. Methods to measure Hb are usually invasive (requiring a blood sample); however, advances in diagnostic and clinical chemistry over the past decade have led to the development of new noninvasive methods. Accurate diagnosis at the individual level is important to identify individuals who require treatment. At the population level, anemia prevalence estimates are often the impetus for national nutrition policies or programs. Thus, it is essential that methods for Hb measurement are sensitive, specific, accurate, and reproducible. The objective of our narrative review is to describe the basic principles, advantages, limitations, and quality control issues related to methods of Hb measurement in clinical and field settings. We also discuss other biomarkers and tests that can help to determine the severity and underlying causes of anemia. In conclusion, there are many established and emerging methods to measure Hb concentration, each with their own advantages, limitations, and factors to consider before use.

The impact of analytical variation of hemoglobin measurement on blood donors' hemoglobin and deferral rates.

BACKGROUND: Donors' hemoglobin (Hb) level must be tested before blood donation. Low Hb is the leading reason for donor deferral. Many donor-related and external factors associated with low Hb are known, but no studies have been conducted concerning the effects of analytical variation on donor Hb measurements and deferrals. STUDY DESIGN AND METHODS: The effects of donors' age, the seasonal and daily distribution of donations, and batch-to-batch variation in HemoCue Hb 201+ cuvettes on donors' capillary Hb (cHb) measurements and deferrals were analyzed for more than 1.7 million donor visits in 2010 to 2016 at a national blood establishment. Furthermore, approximately 3.1 million cHb measurements from the years 2000 to 2009 were included in analyses to correlate measured cHb value and Hb deferral rate. RESULTS: A significant correlation between the mean annual cHb and Hb deferral rate was observed in both women and men. The season of the donation was the strongest explanatory factor for the monthly variation of predonation cHb (explaining 25 and 31% of the variation in women and men, respectively). Batch-to-batch variation in HemoCue cuvettes explained 6.8% of monthly variation in women and 7.4% in men. Monthly changes in donors' age distribution explained 2.5% of monthly variation in women and 2.4% in men. CONCLUSION: Small and, in most clinical settings, negligible analytical variation in Hb measurement methods can have significant consequences when used for Hb screening of blood donors. This should be minimized by using methods in which analytical variation is under control and kept as low as possible.

Detailed view on slow sinusoidal, hemodynamic oscillations on the human brain cortex by Fourier transforming oxy/deoxy hyperspectral images.

Slow sinusoidal, hemodynamic oscillations (SSHOs) around 0.1 Hz are frequently seen in mammalian and human brains. In four patients undergoing epilepsy surgery, subtle but robust fluctuations in oxy- and deoxyhemoglobin were detected using hyperspectral imaging of the cortex. These SSHOs were stationary during the entire 4 to 10 min acquisition time. By Fourier filtering the oxy- and deoxyhemoglobin time signals with a small bandwidth, SSHOs became visible within localized regions of the brain, with distinctive frequencies and a continuous phase variation within that region. SSHOs of deoxyhemoglobin appeared to have an opposite phase and 11% smaller amplitude with respect to the oxyhemoglobin SSHOs. Although the origin of SSHOs remains unclear, we find indications that the observed SSHOs may embody a local propagating hemodynamic wave with velocities in line with capillary blood velocities, and conceivably related to vasomotion and maintenance of adequate tissue perfusion. Hyperspectral imaging of the human cortex during surgery allow in-depth characterization of SSHOs, and may give further insight in the nature and potential (clinical) use of SSHOs.

Accuracy of detection of carboxyhemoglobin and methemoglobin in human and bovine blood with an inexpensive, pocket-size infrared scanner.

Detecting life-threatening common dyshemoglobins such as carboxyhemoglobin (COHb, resulting from carbon monoxide poisoning) or methemoglobin (MetHb, caused by exposure to nitrates) typically requires a laboratory CO-oximeter. Because of cost, these spectrophotometer-based instrument are often inaccessible in resource-poor settings. The aim of this study was to determine if an inexpensive pocket infrared spectrometer and smartphone (SCiO®Pocket Molecular Sensor, Consumer Physics Ltd., Israel) accurately detects COHb and MetHb in single drops of blood. COHb was created by adding carbon monoxide gas to syringes of heparinized blood human or cow blood. In separate syringes, MetHb was produced by addition of sodium nitrite solution. After incubation and mixing, fractional concentrations of COHb or MetHb were measured using a Radiometer ABL-90 Flex® CO-oximeter. Fifty microliters of the sample were then placed on a microscope slide, a cover slip applied and scanned with the SCiO spectrometer. The spectrograms were used to create simple linear models predicting [COHb] or [MetHb] based on spectrogram maxima, minima and isobestic wavelengths. Our model predicted clinically significant carbon monoxide poisoning (COHb ≥15%) with a sensitivity of 93% and specificity of 88% (regression r2 = 0.63, slope P<0.0001), with a mean bias of 0.11% and an RMS error of 21%. Methemoglobinemia severe enough to cause symptoms (>20% MetHb) was detected with a sensitivity of 100% and specificity of 71% (regression r2 = 0.92, slope P<0.001) mean bias 2.7% and RMS error 21%. Although not as precise as a laboratory CO-oximeter, an inexpensive pocket-sized infrared scanner/smartphone detects >15% COHb or >20% MetHb on a single drop of blood with enough accuracy to be useful as an initial clinical screening. The SCiO and similar relatively low cost spectrometers could be developed as inexpensive diagnostic tools for developing countries.

Real-time evaluation of an image analysis system for monitoring surgical hemoglobin loss.

Monitoring blood loss is important for management of surgical patients. This study reviews a device (Triton) that uses computer analysis of a photograph to estimate hemoglobin (Hb) mass present on surgical sponges. The device essentially does what a clinician does when trying to make a visual estimation of blood loss by looking at a sponge, albeit with less subjective variation. The performance of the Triton system is reported upon in during real-time use in surgical procedures. The cumulative Hb losses estimated using the Triton system for 50 enrolled patients were compared with reference Hb measurements during the first quarter, half, three-quarters and full duration of the surgery. Additionally, the estimated blood loss (EBL) was calculated using the Triton measured Hb loss and compared with values obtained from both visual estimation and gravimetric measurements. Hb loss measured by Triton correlated with the reference method across the four measurement intervals. Bias remained low and increased from 0.1 g in the first quarter to 3.7 g at case completion. The limits of agreement remained narrow and increased proportionally from the beginning to the end of the cases, reaching a maximum range of -15.3 to 22.7 g. The median (IQR) difference of EBL derived from the Triton system, gravimetric method and visual estimation versus the reference value were 13 (74), 389 (287), and 4 (230) mL, respectively. Use of the Triton system to measure Hb loss in real-time during surgery is feasible and accurate.

In Vitro Evaluation of a Novel Image Processing Device to Estimate Surgical Blood Loss in Suction Canisters.

BACKGROUND: Clinicians are tasked with monitoring surgical blood loss. Unfortunately, there is no reliable method available to assure an accurate result. Most blood lost during surgery ends up on surgical sponges and within suction canisters. A novel Food and Drug Administration-cleared device (Triton system; Gauss Surgical, Inc, Los Altos, CA) to measure the amount of blood present on sponges using computer image analysis has been previously described. This study reports on performance of a complementary Food and Drug Administration-cleared device (Triton Canister System; Gauss Surgical, Inc, Los Altos, CA) that uses similar image analysis to measure the amount of blood in suction canisters. METHODS: Known quantities of expired donated whole blood, packed red blood cells, and plasma, in conjunction with various amounts of normal saline, were used to create 207 samples representing a wide range of blood dilutions commonly seen in suction canisters. Each sample was measured by the Triton device under 3 operating room lighting conditions (bright, medium, and dark) meant to represent a reasonable range, resulting in a total of 621 measurements. Using the Bland-Altman method, the measured hemoglobin (Hb) mass in each sample was compared to the results obtained using a standard laboratory assay as a reference value. The analysis was performed separately for samples measured under each lighting condition. It was expected that under each separate lighting condition, the device would measure the various samples within a prespecified clinically significant Hb mass range (±30 g per canister). RESULTS: The limits of agreement (LOA) between the device and the reference method for dark (bias: 4.7 g [95% confidence interval {CI}, 3.8-5.6 g]; LOA: -8.1 g [95% CI, -9.7 to -6.6 g] to 17.6 g [95% CI, 16.0-19.1 g]), medium (bias: 3.4 g [95% CI, 2.6-4.1 g]; LOA: -7.4 g [95% CI, -8.7 to -6.1 g] to 14.2 g [95% CI, 12.9-15.5 g]), and bright lighting conditions (bias: 4.1 g [95% CI, 3.2-4.9 g]; LOA: -7.6 g [95% CI, -9.0 to -6.2 g] to 15.7 g [95% CI, 14.3-17.1 g]) fell well within the predetermined clinically significant limits of ±30 g. Repeated measurements of the samples under the various lighting conditions were highly correlated with intraclass correlation coefficient of 0.995 (95% CI, 0.993-0.996; P < .001), showing that lighting conditions did not have a significant impact on measurements. Hb mass bias was significantly associated with hemolysis level (Spearman ρ correlation coefficient, -0.137; P = .001) and total canister volume (Spearman ρ correlation coefficient, 0.135; P = .001), but not ambient illuminance. CONCLUSIONS: The Triton Canister System was able to measure the Hb mass reliably with clinically acceptable accuracy in reconstituted blood samples representing a wide range of Hb concentrations, dilutions, hemolysis, and ambient lighting settings.

Predicting changes in hemoglobin S after simple transfusion using complete blood counts.

BACKGROUND: Hemoglobin S percentages are used in the management of patients who have sickle cell disease. However, hemoglobin S measurements often are not routinely or rapidly performed. Rapid and accurate methods to estimate hemoglobin S levels after simple transfusion may improve the care of patients with sickle cell disease. STUDY DESIGN AND METHODS: A comprehensive review of the electronic medical record identified 24 stable patients with sickle cell disease who received simple red blood cell transfusions and had hemoglobin S measurements before and after the transfusion that were less than 72 hours apart. Examination of these patients identified 62 separate transfusions that met our criteria. Three simple equations that utilized complete blood count values and readily available information from the medical record were used to predict the post-transfusion hemoglobin S level after transfusion (Equation 1: predicted post-transfusion hemoglobin = pre-transfusion hemoglobin S × [pre-transfusion hemoglobin/post-transfusion hemoglobin]; Equation 2: predicted post-transfusion hemoglobin S = pre-transfusion hemoglobin S × [pre-transfusion hematocrit/post-transfusion hematocrit]; and Equation 3: predicted post-transfusion hemoglobin S = pre-transfusion hemoglobin S × total pre-transfusion hemoglobin/[total pre-transfusion hemoglobin + (red blood cell volume × 20)]). RESULTS: The predicted hemoglobin S values for all three equations showed a highly significant correlation with the measured post-hemoglobin S value. The coefficient of determination (R2 ) for Equations 1, 2, and 3 was 0.95, 0.92, and 0.97, respectively. Predicting the post-transfusion hemoglobin S value using estimates of the patient's total hemoglobin and the transfused hemoglobin (Equation 3) was the most precise. CONCLUSION: Reductions in hemoglobin S values in patients with sickle cell disease who receive simple red blood cell transfusions can be reliably predicted using complete blood cell measurements and simple arithmetic equations.

Clinical Experience with the Implementation of Accurate Measurement of Blood Loss during Cesarean Delivery: Influences on Hemorrhage Recognition and Allogeneic Transfusion.

OBJECTIVE: This article compares hemorrhage recognition and transfusion using accurate, contemporaneous blood loss measurement versus visual estimation during cesarean deliveries. STUDY DESIGN: A retrospective cohort study using visually estimated blood loss (traditional, n = 2,025) versus estimates using a mobile application that photographs sponges and canisters and calculates their hemoglobin content (device, n = 756). RESULTS: Blood loss > 1,000 mL was recognized in 1.9% of traditional visual estimation patients, while measured blood loss of > 1,000 mL occurred in 8.2% of device patients (p < 0.0001). In both groups, this was accompanied by a greater decrease in transfusion-adjusted hemoglobin levels than occurred in patients without hemorrhage (p < 0.0001). Despite similar transfusion rates (1.6% in both groups), fewer red cell units were given to transfused patients in the device group (1.83 ± 0.58 versus 2.56 ± 1.68 units; p = 0.038). None of the patients in the device group received plasma or cryoprecipitate. Seven patients in the traditional group received these products (p = 0.088). Device use was associated with shorter hospital stays (4.0 ± 2.3 versus 4.4 ± 2.9 days; p = 0.0006). CONCLUSION: The device identified hemorrhages more frequently than visual estimation. Device-detected hemorrhages appeared clinically relevant. Blood product transfusion was reduced possibly due to earlier recognition and treatment, although further studies are needed to verify the conclusion.

Guidance for faecal occult blood testing: quantitative immunochemical method (FIT-HB) in colorectal cancer screening programmes. / Guida per la determinazione del sangue occulto fecale: metodo immunochimico quantitativo (FIT-HB) nei programmi di screening per il carcinoma colorettale

BACKGROUND: in Italy, colorectal cancer screening is included as part of the Italian National Health Service - SSN (Servizio Sanitario Nazionale) Essential Levels of Care - LEA (Livelli Essenziali Assistenziali) and the European Guidelines, which specify quantitative FIT-Hb testing as the best strategy for organised screening programmes. To ensure consistent operating standards in Member States, European regulations require the implementation of certification and accreditation requirements for diagnostic and care-related processes. The requirement, based on ISO 17021 accreditation standards, includes ISO 9001 certification for systems and ISO 15189:2012 accreditation for laboratories. METHODOLOGY: various phases of the analytical process (pre-test, test, post-test) were evaluated in detail and provided operational guidelines for adjusting analytical and managerial procedures using: (a) feedback from members of GISCoR screening labs; (b) performance data obtained via a systematic review of the literature and the Osservatorio Nazionale Screening (ONS) Survey; (c) recommendations for laboratory practice issued by the World Endoscopy Organization "FIT for Screening" Working Group; (d) selected guidelines from the National Guidelines Clearinghouse database; and (e) Canadian, Australian and European screening programme websites. With respect to ISO 15189:2012 standards for accreditation of medical laboratories, GISCoR's guidance has been re-evaluated and revised by auditors from the Italian certification body (ACCREDIA) to assess its compliance and completeness with the aim of finalising operating procedures. CONCLUSIONS: the implementation and maintenance of operational standards required by complex systems (e.g. screening programmes) involving constant interaction between facilities and the supporting organisational structure are not easy to achieve. The guide aims to provide laboratories with the necessary guidance for proper process management.

Objective evaluation of analyzer performance based on a retrospective meta-analysis of instrument validation studies: point-of-care hematology analyzers.

BACKGROUND: Information on quality requirements and objective evaluation of performance of veterinary point-of-care analyzers (POCAs) is scarce. OBJECTIVES: The study was aimed at assessing observed total errors (TEobs s) for veterinary hematology POCAs via meta-analysis and comparing TEobs to allowable total error (TEa ) specifications based on experts' opinions. METHODS: The TEobs for POCAs (impedance and laser-based) was calculated based on data from instrument validation studies published between 2006 and 2013 as follows: TEobs = 2 × CV [%] + bias [%]. The CV was taken from published studies; the bias was estimated from the regression equation at 2 different concentration levels of measurands. To fulfill quality requirements, TEobs should be < TEa . Measurands were considered as globally acceptable if > 60% of analyzers showed TEobs < TEa . RESULTS: Six studies evaluating 11 analyzers and 5 studies evaluating 5 analyzers were included for canine and feline hematology variables, respectively. For the CBC, TEobs was < 15% for canine and < 13% for feline measurands, except for HGB and platelet counts. Measurands of the CBC, excluding differential WBC and platelet counts, and HGB concentration were considered globally acceptable. For most of the cell types in the WBC differential count, TEobs was > TEa (data from 3 analyzers). CONCLUSION: This meta-analysis is considered a pilot study. Experts' requirements (TEobs < TEa ) were fulfilled for most measurands except HGB (due to instrument-related bias for the ADVIA 2120) and platelet counts. Available data on the WBC differential count suggest an analytic bias, so nonstatistical quality control is recommended.