Evaluation of a portable hemoglobinometer (HemoCue) to control anemia in hepatitis C liver transplant recipients undergoing antiviral therapy

[Comparison of a portable hemoglobinometer (Verio Q Red) with clinical laboratory results in routine clinical practice]

OBJECTIVE

To analyze the concordance between a hemoglobinometer with capillary blood sample and the clinical laboratory with a venous blood sample.

DESIGN

Cross-sectional concordance study.

LOCATION

Care Centre Primary Bufalà-Canyet Primary and Care Centre Primary Dalt la Vila Primary Care Center, Badalona, Barcelona.

PARTICIPANTS

Random selection of participants who attended routine blood tests. Over 18years old. No abandonment or loss was obtained.

MAIN INTERVENTIONS AND MEASUREMENTS

Sex, age, and reason for the blood test were collected from the medical history. Venous blood is drawn, and simultaneously, capillary blood is collected.

RESULTS

120 individuals are included, with an average age of 58.9years. The Bland-Almant graph showed differences within the confidence intervals for hemoglobin and hematocrit. The mean differences between the values of the Verio Q Red hemoglobinometer and those of the clinical laboratory were -0.42mg/dl for hemoglobin and -1.25% for hematocrit. The intraclass correlation coefficient showed excellent correlation for hemoglobin and hematocrit between the Verio Q Red hemoglobinometer and the clinical laboratory. Pearson's correlation for hemoglobin was 0.737 and for hematocrit 0.787.

CONCLUSIONS

The Verio Q hemoglobinometer is a valid tool for the early diagnosis of anemias and can be very useful in primary care consultations.

Invasive and non-invasive point-of-care testing and point-of-care monitoring of the hemoglobin concentration in human blood - how accurate are the data?

In this review, scientific investigations of point-of-care testing (POCT) and point-of-care monitoring (POCM) devices are summarized with regard to the measurement accuracy of the hemoglobin concentration. As a common basis, information according to the Bland and Altman principle [bias, limits of agreement (LOA)] as well as the measurement accuracy and precision are considered, so that the comparability can be mapped. These collected data are subdivided according to the manufacturers, devices and procedures (invasive and non-invasive). A total of 31 devices were identified. A comparability of the scientific investigations in particular was given for 23 devices (18 invasive and five non-invasive measuring devices). In terms of measurement accuracy, there is a clear leap between invasive and non-invasive procedures, while no discernible improvement can be derived in the considered time frame from 2010 to 2018. According to the intended use, strict specifications result from the clinical standards, which are insufficiently met by the systems. More stringent requirements can be derived both in the area of blood donation and in the treatment of patients.

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.

Portable hemoglobinometer is a reliable technology for the follow-up of venesections tolerance in hemochromatosis

BACKGROUND

The treatment of HFE-related hemochromatosis, one of the most common genetic diseases, is based on phlebotomies whose tolerance is evaluated by regular monitoring of hemoglobin. Using a portable hemoglobinometer (PH) could provide an easy and fast determination of hemoglobin. Therefore, the aim of the present study was to compare, in hemochromatosis patients treated by bloodletting, the hemoglobin concentrations as assayed, on capillary blood, by a PH device and, on venous blood, by a cell counter (CC) device.

METHODS

For a total period of 12 weeks duration, all patients undergoing phlebotomies in the same hospital outpatient unit had hemoglobin determinations both by the HemoCue and by the laboratory's DxH 800 Coulter. To evaluate the sensitivity and specificity of the HemoCue, patients were classified as presenting or not anemia as defined by hemoglobin level below 11 g/dl.

RESULTS

Measurements of hemoglobin were performed in 122 patients. The sensitivity and specificity of PH compared to CC were 100 and 98.1%, respectively. Capillary hemoglobin by PH slightly underestimated venous hemoglobin by CC. The Pearson's correlation coefficient between PH and CC was 0.80 (P<0.0001).

CONCLUSION

PH is a reliable, quick and easy technology, which can be proposed to follow-up the tolerance of venesections in hemochromatosis patients.

Systematic Review and Meta-Analysis of Method Comparison Studies of Masimo Pulse Co-Oximeters (Radical-7™ or Pronto-7™) and HemoCue® Absorption Spectrometers (B-Hemoglobin or 201+) with Laboratory Haemoglobin Estimation

We assessed agreement in haemoglobin measurement between Masimo pulse co-oximeters (Rad-7™ and Pronto-7™) and HemoCue® photometers (201+ or B-Hemoglobin) with laboratory-based determination and identified 39 relevant studies (2915 patients in Masimo group and 3084 patients in HemoCue group). In the Masimo group, the overall mean difference was -0.03 g/dl (95% prediction interval -0.30 to 0.23) and 95% limits of agreement -3.0 to 2.9 g/dl compared to 0.08 g/dl (95% prediction interval -0.04 to 0.20) and 95% limits of agreement -1.3 to 1.4 g/dl in the HemoCue group. Only B-Hemoglobin exhibited bias (0.53, 95% prediction interval 0.27 to 0.78). The overall standard deviation of difference was larger (1.42 g/dl versus 0.64 g/dl) for Masimo pulse co-oximeters compared to HemoCue photometers. Masimo devices and HemoCue 201+ both provide an unbiased, pooled estimate of laboratory haemoglobin. However, Masimo devices have lower precision and wider 95% limits of agreement than HemoCue devices. Clinicians should carefully consider these limits of agreement before basing transfusion or other clinical decisions on these point-of-care measurements alone.

Hemoglobin point-of-care testing: the HemoCue system

Besides the use of traditional laboratory resources, the diagnosis of anemia can also be accomplished by assessing hemoglobin (Hb) concentration with point-of-care testing (POCT) devices such as the HemoCue test systems. In several situations, these devices might suitably replace traditional laboratory testing, including several areas of health care where a very rapid Hb measurement might be required to make immediate therapeutic decisions. The use of these devices, however, should fulfill some basic criteria, including economic, clinical, and regulatory issues; appropriate training of the users and knowledge of test requirements, performance, limitations, and potential interferences; the use of venous and arterial sampling, when possible; and a rigorous quality assessment, which should be under the responsibility of laboratory professionals. Because of its optimal performance along with the fact that the HemoCue is probably one of the most commonly used devices worldwide, the aim of this article is to review the literature data about the performance of this test system as compared with laboratory reference testing estimations and according to the biological matrix.