Evaluation of the validity of a rapid method for measuring high and low haemoglobin levels in whole blood donors

A Comparative Study of Serum Ferritin Levels Among Unfit and Fit Blood Donors

Background:

Cheap methodologies are being utilized by low-resource countries to determine blood donors' fitness. Important hematological biomarkers might have to be evaluated to enhance the use of these methods.

Aims:

The study evaluated the pattern of serum ferritin in 18–24 fit and unfit prospective blood donors (PDBs) and the prevalence of iron store deficiency.

Settings and Design:

This study was a cross-sectional, comparative study which was conducted at the blood donor clinic of the Lagos University Teaching Hospital.

Materials and Methods:

Blood samples were collected by venipuncture into sodium-ethylenediaminetetraacetic acid and plain bottles. The latter was centrifuged and used for ferritin determination via human ferritin enzyme-linked immunosorbent assay test kit, while the former was used for red cell indices analysis using an autoanalyzer.

Statistical Analysis:

Data were analyzed using SPSS version 20, values were presented as mean ± standard deviation, and P ≤ 0.05 was considered statistically significant.

Results:

A total of 263 PDB were recruited into the study consisting of 210 (79%) males and 53 (21%) females, with a mean age of 32.88 ± 8.22. Only 110 (41.8%) of the participants were considered fit, while 153 (58.2%) were unfit using copper sulfate specific gravity. There was no statistically significant difference (P = 0.301) in the mean level of serum ferritin in unfit blood donors (74.5 ± 90.8 μg/L) compared to that of the fit blood donors (61.5 ± 54.5 μg/L). The prevalence of iron store depletion among blood donors in Lagos state was 11.8% (31 of 263) with a higher proportion (7.6%) occurring among unfit donors. However, low levels of serum ferritin (<15 μg/L) were significantly associated with the occurrence of anemia (hemoglobin < 12.5 g/gl) among unit donors (19%; P = 0.05).

Conclusion:

Although serum ferritin depletion appears to be higher in the unfit blood donors, the use of serum ferritin as an index for the screening and determination of PDBs' fitness requires further evaluation.

Hemoglobin concentration and anemia diagnosis in venous and capillary blood: biological basis and policy implications

Anemia is an important public health challenge and accurate prevalence estimates are needed for program planning and tracking progress. While venous blood assessed by automated hematology analyzers is considered gold standard, most population‐based surveys use point‐of‐care diagnostics and capillary blood to estimate population prevalence of anemia. Several factors influence hemoglobin (Hb) concentration, including human and analytic error, analysis method, and type of instrument, but it is unclear whether biological variability exists between venous and capillary blood. The objective of this paper was to systematically review sources of Hb variability and the potential biological basis for venous and capillary differences. We use data from a recent survey in the state of Uttar Pradesh, India, to illustrate the implications on anemia prevalence estimates. Significant differences in Hb concentration between capillary and venous blood samples are common. Most but not all find capillary Hb concentration to be higher than venous. Instrument/method variability and human error play an important role, but cannot fully explain these differences. A normative guide to data collection, analysis, and anemia diagnosis is needed to ensure consistent and appropriate interpretation. Further research is needed to fully understand the biological implications of venous and capillary Hb variability.

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.

Diabetes care in the dispersed population of Greenland. A new model based on continued monitoring, analysis and adjustment of initiatives taken

Diabetes used to be a rare condition among Inuit in Greenland. However, research in recent decades has shown a high prevalence of undiagnosed diabetes. Addressing diabetes in the geographically dispersed population of Greenland presents a challenge to the health care system. In 2008, a new model of diabetes care was introduced in Greenland that included continual monitoring, analysis, and adjustment of initiatives taken. The overall aim of this review was to review the feasibility of the monitoring of an ongoing national diabetes care programme. After ten years of observation it was clear that monitoring of such a programme based on information in electronic medical records in Greenland was feasible. It was found that the majority of the population in Greenland was in contact with the health care system. Increased diagnostic activity resulted in an increased prevalence of diagnosed diabetes. The quality of diabetes care in Greenland and the testing effectiveness of gestational diabetes were improved. Microvascular complications were frequently observed among Greenlandic diabetic patients, except for retinopathy that was as an exception. In summary, this model may improve diabetes care and potentially care for other chronic conditions in Greenland, and may also be helpful in other remote settings where chronic disease care is difficult.Abbreviations: AD: Anno Domini; ADA: American Diabetes Association; BC: Before Christ; BMI: Body Mass Index; BP: Blood Pressure; CWB: Capillary Whole Blood; EMR: Electronic Medical Record; EASD: European Association for Study of Diabetes; GA: Gestational Age; GDM: Gestational Diabetes Mellitus; FIGO: The International Federation of Gynaecology and Obstetrics; HbA1c: Glycosylated haemoglobin; IDF: International Diabetes Federation; LDL: Low density lipoprotein; NDQIA: National Diabetes Quality Improvement Alliancel; NICE: National Institute for Health and Care Excellence; OECD: Organisation for Economic Co-operation and Development; OGTT: Oral Glucose Tolerance Test; QIH: Queen Ingrid Hospital; RCT: Randomised Controlled Tria;l T1D: Type 1 Diabetes; T2D: Type 2 Diabetes; UACR: Urine Albumin Creatinine Ratio; WHO: World Health Organisation.

Hemoglobin concentration, total hemoglobin mass and plasma volume in patients: implications for anemia

In practice, clinicians generally consider anemia (circulating hemoglobin concentration < 120 g.l^-1 in non-pregnant females and < 130 g.l^-1 in males) as due to impaired hemoglobin synthesis or increased erythrocyte loss or destruction. Rarely is a rise in plasma volume relative to circulating total hemoglobin mass considered as a cause. But does this matter? We explored this issue in patients, measuring hemoglobin concentration, total hemoglobin mass (optimized carbon monoxide rebreathing method) and thereby calculating plasma volume in healthy volunteers, surgical patients, and those with inflammatory bowel disease, chronic liver disease or heart failure. We studied 109 participants. Hemoglobin mass correlated well with its concentration in the healthy, surgical and inflammatory bowel disease groups (r=0.687-0.871, P<0.001). However, they were poorly related in liver disease (r=0.410, P=0.11) and heart failure patients (r=0.312, P=0.16). Here, hemoglobin mass explained little of the variance in its concentration (adjusted R²=0.109 and 0.052; P=0.11 and 0.16), whilst plasma volume did (R² change 0.724 and 0.805 in heart and liver disease respectively, P<0.0001). Exemplar patients with identical (normal or raised) total hemoglobin masses were diagnosed as profoundly anemic (or not) depending on differences in plasma volume that had not been measured or even considered as a cause. The traditional inference that anemia generally reflects hemoglobin deficiency may be misleading, potentially resulting in inappropriate tests and therapeutic interventions to address 'hemoglobin deficiency' not 'plasma volume excess'. Measurement of total hemoglobin mass and plasma volume is now simple, cheap and safe, and its more routine use is advocated.

Effects of preanalytical factors on hemoglobin measurement: A comparison of two HemoCue® point-of-care analyzers

BACKGROUND

In field studies, hemoglobin (Hb) is often measured using a battery-operated, portable HemoCue® hemoglobinometer.

METHODS

We compared the performance of 2 HemoCue® models (Hb-201+ and Hb-301) and investigated effects of preanalytical factors on Hb results by simulating unfavorable field conditions.

RESULTS

The Hb-301 produced 2.6% higher results compared to the Hb-201+. Hb had to be measured within 1min of filling the Hb-301 cuvette to avoid artificially elevated concentrations (1.3% per min). The Hb-301 cuvettes withstood elevated temperature (37°C) and humidity (72%) for 3weeks, while the Hb-201+ cuvettes degraded within 10min under those conditions. Both cuvette types withstood elevated temperature for 3weeks. Properly-collected venous and capillary blood produced comparable results. Pooled capillary blood produced comparable results to the second and third but not the fourth drop of blood (3.3% lower). Blood could be stored for ≤4days at 10-30°C before Hb-201+ measurement, but only for 1day at 10-23°C before Hb-301 measurement (≤1% change in Hb).

CONCLUSIONS

Higher Hb results obtained with the Hb-301 may influence the interpretation of anemia prevalence in health surveys. While the Hb-301 performed better in high humidity conditions, the Hb-201+ provided more user flexibility regarding delayed Hb reading.