Experienced Laboratory Technicians Research Articles

Normal sperm head morphometric reference values in fertile Asian males.

Sperm head morphology is crucial for male factor infertility diagnosis and assessment of male reproductive potential. Several criteria are available to analyze sperm head morphology, but they are limited by poor methodology comparability and population applicability. This study aimed to explore comprehensive and new normal morphometric reference values for spermatozoa heads in fertile Asian males. An automated sperm morphology analysis system captured 23 152 stained spermatozoa from confirmed fertile males. Of these samples, 1856 sperm head images were annotated by three experienced laboratory technicians as "normal". We employed 14 novel morphometric features to describe sperm head size (head length, head width, length/width ratio, and girth), shape (ellipse intersection over union, girth intersection over union, short-axis symmetry, and long-axis symmetry), area (head, acrosome, postacrosomal areas, and acrosome area ratio), and degrees of acrosome and nuclear uniformity. This straight-forward method for the morphometric analysis of sperm by accurate visual measurements is clinically applicable. The measured parameters present valuable information to establish morphometric reference intervals for normal sperm heads in fertile Asian males. The presented detailed measurement data will be valuable for interlaboratory comparisons and technician training. In vitro fertilization and andrology laboratory technicians can use these parameters to perform objective morphology evaluation when assessing male fertilization potential.

Evaluation of the performance of sysmex XN-3100 automated hematology analyzer regarding the sysmex XE-2100 and microscopic examination

Abstract Objectives We performed a verification study of the Sysmex XN-3100 hematology analyzer in comparison with the XE-2100 according to the guidelines of the Clinical and Laboratory Standards Institute (CLSI) and the International Council for Standardization in Hematology (ICSH). Materials and methods Blood samples and quality control materials were used for precision. For comparison, we used the current XE-2100 as the comparative method and analyzed 540 blood samples. The Passing-Bablok and Bland-Altman tests were performed according to the CLSI EP09-A3 and a carryover study was performed according to the CLSI H26-A2 guidelines. The flagging performance of the two analyzers was compared, using two experienced laboratory technicians as the reference method. Results The Sysmex XN-3100 demonstrated high levels of precision for most parameters. For the comparison analysis, all parameters, except for MCHC, monocytes and basophils were within the systematic error limits of desirable biological variability criterion (SeDBV). The carryover was less than 0.4% for all parameters. The flagging performance of the XN-3100 was satisfactory and the overall efficiency was high. Conclusions The XN-3100 not only showed a strong correlation and agreement with the XE-2100 but also displayed a comparable analytical sensitivity, and increased specificity, which may result in an improved turnaround time and throughpu.

Fibrin Clot Formation and Lysis in Plasma.

Disturbance in the balance between fibrin formation and fibrinolysis can lead to either bleeding or thrombosis; however, our current routine coagulation assays are not sensitive to altered fibrinolysis. The clot formation and lysis assay is a dynamic plasma-based analysis that assesses the patient’s capacity for fibrin formation and fibrinolysis by adding an activator of coagulation as well as fibrinolysis to plasma and measuring ex vivo fibrin clot formation and breakdown over time. This assay provides detailed information on the fibrinolytic activity but is currently used for research only, as the assay is prone to inter-laboratory variation and as it demands experienced laboratory technicians as well as specialized personnel to validate and interpret the results. Here, we describe a protocol for the clot formation and lysis assay used at our research laboratory.

Performance of a web-based application measuring spot quality in dried blood spot sampling

Background The dried blood spot (DBS) method allows patients and researchers to collect blood on a sampling card using a skin-prick. An important issue in the application of DBSs is that samples for therapeutic drug monitoring are frequently rejected because of poor spot quality, leading to delayed monitoring or missing data. We describe the development and performance of a web-based application (app), accessible on smartphones, tablets or desktops, capable of assessing DBS quality at the time of sampling by means of analyzing a picture of the DBS. Methods The performance of the app was compared to the judgment of experienced laboratory technicians for samples obtained in a trained and untrained setting. A robustness- and user test were performed. Results In a trained setting the app yielded an adequate decision in 90.0% of the cases with 4.1% false negatives (insufficient quality DBSs incorrectly not rejected) and 5.9% false positives (sufficient quality DBSs incorrectly rejected). In an untrained setting this was 87.4% with 5.5% false negatives and 7.1% false positives. A patient user test resulted in a system usability score of 74 out of 100 with a median time of 1 min and 45 s to use the app. Robustness testing showed a repeatability of 84%. Using the app in a trained and untrained setting improves the amount of sufficient quality samples from 80% to 95.9% and 42.2% to 87.9%, respectively. Conclusions The app can be used in trained and untrained setting to decrease the amount of insufficient quality DBS samples.

Feedback from the European Bioanalysis Forum liquid microsampling consortium: microsampling: assessing accuracy and precision of handheld pipettes and capillaries.

Aim: Microsampling in preclinical pharmacokinetics (PK) studies is currently widely adopted across the pharmaceutical industry. Materials & methods: The European Bioanalysis Forum liquid microsampling consortium member companies assessed the accuracy and precision of handheld pipettes and microcapillaries at volumes of less than 10μl. The following key factors on pipetting performance were also evaluated: Pipette type (positive displacement, air displacement and microcapillary), experience of user and the liquid type. Water was selected as a best-case scenario for accuracy and precision determination and blood plasma as a 'real world' bioanalysis sample type. Conclusion: Accuracy and precision on the pipetted volume decreased at lower volumes and experienced laboratory technicians performed better compared with the infrequent users. With respect to the pipetting devices used, microcapillaries showed better or equivalent accuracy and precision compared with handheld pipettes across the volume range 1-8μl independent of the matrix used.

A Computer-Vision-Guided Robot Arm for Automatically Placing Grids in Pioloform Film Preparation

Preparing pioloform/formvar support films on transmission electron microscopy (TEM) grids is a routine laboratory procedure in practically all electron microscopy units. In current practice, these grids are manually placed on the support film one by one using special tweezers, a process requiring a steady hand. The work is often ergonomically awkward to continue for a longer period of time. In this article, we describe a low-cost, computer vision-guided robot arm that automatically places the grids on the film. The success rate of the prototype robot is 90%, which is comparable to an experienced laboratory technician.

NILAI DIAGNOSTIK MALARIA ANTIGEN CASSETTE PENYAKIT MALARIA

Malaria is an endemic disease in many countries. In 103 endemic countries with around 2.5 billion population, 1−3 million death cases were reported every year. Clinical criteria and blood smear established the diagnosis of malaria. ICT (imuno chromatographytest) is needed in peripheral areas where there are no experienced laboratory technicians. The procedure is simple, practical, easy, aswell as quicker than the conventional method, and no experienced technicians are needed this ICT advantages. The aim of this study isto know the diagnostic value of Malaria Antigen Cassette with microscopic examination as the gold standard examination of malaria.This research used observational cross-sectional method This study was done in Nusa Tenggara Barat during May−June 2008. Bloodsamples were taken by finger prick in patients with Malaria symptoms: fever, chill and sweating, followed by examining the blood smearby Malaria Antigen Cassette from Focus Diagnostic. The diagnostic value was then evaluated by calculating the sensitivity, specificity,positive predictive value as well as the negative predictive value. The diagnostic value of Malaria Antigen Cassette in patients withmalaria falciparum was found as follows: sensitivity 95.2%, specificity 100%, positive predictive value 100%, and negative predictivevalue 97.6%. The diagnostic value of Malaria Antigen Cassette in patients other types than malaria falciparum was as follows: sensitivity94.8%, specificity 100%, positive predictive value 100%, and negative predictive value 95.3%. The diagnostic value of Malaria AntigenCassette was very high in diagnosing malaria falciparum compared to other types than malaria falciparum.

Automatic platelets counter for supporting dengue case detection in primary health care in indonesia.

Dengue fever is a major problem in many developing countries, including Indonesia. Laboratory examination is used to diagnose dengue infection and to monitor disease progression. Hematology tests, such as platelet count, are also used for timely recognition of the development of severe dengue. In primary health care centers platelet counting is typically performed manually, which is labor intensive and requires an experienced laboratory technician. To address this challenge, we have developed an automatic platelet counter for primary health care and resource-poor settings. The technology is based on a conventional microscope equipped with a digital camera linked to a personal computer, which can capture and analyze microscope images of blood samples. To evaluate the accuracy of the technology, it was compared to platelet counts performed manual by an experienced laboratory technician. Statistical analysis shows no difference between the techniques with a kappa coefficient of 0.6. This method is judged to have great potential as a tool to help primary health centers and other facilities with limited resources to deal with the burden of dengue.

Do Instructional Videos on Sputum Submission Result in Increased Tuberculosis Case Detection? A Randomized Controlled Trial.

ObjectiveWe examined the effect of an instructional video about the production of diagnostic sputum on case detection of tuberculosis (TB), and evaluated the acceptance of the video.Trial DesignRandomized controlled trial.MethodsWe prepared a culturally adapted instructional video for sputum submission. We analyzed 200 presumptive TB cases coughing for more than two weeks who attended the outpatient department of the governmental Municipal Hospital in Mwananyamala (Dar es Salaam, Tanzania). They were randomly assigned to either receive instructions on sputum submission using the video before submission (intervention group, n = 100) or standard of care (control group, n = 100). Sputum samples were examined for volume, quality and presence of acid-fast bacilli by experienced laboratory technicians blinded to study groups.ResultsMedian age was 39.1 years (interquartile range 37.0–50.0); 94 (47%) were females, 106 (53%) were males, and 49 (24.5%) were HIV-infected. We found that the instructional video intervention was associated with detection of a higher proportion of microscopically confirmed cases (56%, 95% confidence interval [95% CI] 45.7–65.9%, sputum smear positive patients in the intervention group versus 23%, 95% CI 15.2–32.5%, in the control group, p <0.0001), an increase in volume of specimen defined as a volume ≥3ml (78%, 95% CI 68.6–85.7%, versus 45%, 95% CI 35.0–55.3%, p <0.0001), and specimens less likely to be salivary (14%, 95% CI 7.9–22.4%, versus 39%, 95% CI 29.4–49.3%, p = 0.0001). Older age, but not the HIV status or sex, modified the effectiveness of the intervention by improving it positively. When asked how well the video instructions were understood, the majority of patients in the intervention group reported to have understood the video instructions well (97%). Most of the patients thought the video would be useful in the cultural setting of Tanzania (92%).ConclusionsSputum submission instructional videos increased the yield of tuberculosis cases through better quality of sputum samples. If confirmed in larger studies, instructional videos may have a substantial effect on the case yield using sputum microscopy and also molecular tests. This low-cost strategy should be considered as part of the efforts to control TB in resource-limited settings.Trial RegistrationPan African Clinical Trials Registry PACTR201504001098231

Interlaboratory Reproducibility of Blood Morphology Using the Digital Microscope.

Differential counting of peripheral blood cells is an important diagnostic tool. However, manual morphological analysis using the microscope is time-consuming and requires highly trained personnel. The digital microscope is capable of performing an automated peripheral blood cell differential, which is as reliable as manual classification by experienced laboratory technicians. To date, information concerning the interlaboratory variation and quality of cell classification by independently operated digital microscopy systems is limited. We compared four independently operated digital microscope systems for their ability in classifying the five main peripheral blood cell classes and detection of blast cells in 200 randomly selected samples. Set against the averaged results, the R(2) values for neutrophils ranged between 0.90 and 0.96, for lymphocytes between 0.83 and 0.94, for monocytes between 0.77 and 0.82, for eosinophils between 0.70 and 0.78, and for blast cells between 0.94 and 0.99. The R(2) values for the basophils were between 0.28 and 0.34. This study shows that independently operated digital microscopy systems yield reproducible preclassification results when determining the percentages of neutrophils, eosinophils, lymphocytes, monocytes, and blast cells in a peripheral blood smear. Detection of basophils was hampered by the low incidence of this cell class in the samples.

Repeated stool sampling and use of multiple techniques enhance the sensitivity of helminth diagnosis: A cross-sectional survey in southern Lao People's Democratic Republic

Intestinal parasitic infections are common in Lao People's Democratic Republic (Lao PDR). We investigated the accuracy of the Kato-Katz (KK) technique in relation to varying stool sampling efforts, and determined the effect of the concurrent use of a quantitative formalin-ethyl acetate concentration technique (FECT) for helminth diagnosis and appraisal of concomitant infections. The study was carried out between March and May 2006 in Champasack province, southern Lao PDR. Overall, 485 individuals aged ≥6 months who provided three stool samples were included in the final analysis. All stool samples were subjected to the KK technique. Additionally, one stool sample per individual was processed by FECT. Diagnosis was done under a light microscope by experienced laboratory technicians. Analysis of three stool samples with KK plus a single FECT was considered as diagnostic ‘gold’ standard and resulted in prevalence estimates of hookworm, Opisthorchis viverrini, Ascaris lumbricoides, Trichuris trichiura and Schistosoma mekongi infection of 77.9%, 65.0%, 33.4%, 26.2% and 24.3%, respectively. As expected, a single KK and a single FECT missed a considerable number of infections. While our diagnostic ‘gold’ standard produced similar results than those obtained by a mathematical model for most helminth infections, the ‘true’ prevalence predicted by the model for S. mekongi (28.1%) was somewhat higher than after multiple KK plus a single FECT (24.3%). In the current setting, triplicate KK plus a single FECT diagnosed helminth infections with high sensitivity. Hence, such a diagnostic approach might be utilised for generating high-quality baseline data, assessing anthelminthic drug efficacy and rigorous monitoring of community interventions.

OvaSpec – A vision-based instrument for assessing concentration and developmental stage of Trichuris suis parasite egg suspensions

BackgroundOvaSpec is a new, fully automated, vision-based instrument for assessing the quantity (concentration) and quality (embryonation percentage) of Trichuris suis parasite eggs in liquid suspension. The eggs constitute the active pharmaceutical ingredient in a medicinal drug for the treatment of immune-mediated diseases such as Crohn׳s disease, ulcerative colitis, and multiple sclerosis. MethodsThis paper describes the development of an automated microscopy technology, including methodological challenges and design decisions of relevance for the future development of comparable vision-based instruments. Morphological properties are used to distinguish eggs from impurities and two features of the egg contents under brightfield and darkfield illumination are used in a statistical classification to distinguish eggs with undifferentiated contents (non-embryonated eggs) from eggs with fully developed larvae inside (embryonated eggs). ResultsFor assessment of the instrument׳s performance, six egg suspensions of varying quality were used to generate a dataset of unseen images. Subsequently, annotation of the detected eggs and impurities revealed a high agreement with the manual, image-based assessments for both concentration and embryonation percentage (both error rates <1.0%). Similarly, a strong correlation was demonstrated in a final, blinded comparison with traditional microscopic assessments performed by an experienced laboratory technician. ConclusionsThe present study demonstrates the applicability of computer vision in the production, analysis, and quality control of T. suis eggs used as an active pharmaceutical ingredient for the treatment of autoimmune diseases.

Galvanic gold plating for fixed dental prosthesis

Metal ceramic partial fixed dental prostheses have been commonly used for the replacement of missing teeth for many years. Because of an increase in the price of gold, base metal alloys have been the choice of alloy for the fabrication of metal ceramic restorations in many dental clinics. Some major disadvantages of base metals are their corrosion and the dark coloration they may cause at the crown margins. This article describes a galvanic gold-plating technique, which is used to minimize corrosion and improve the esthetics of metal ceramic restorations fabricated with Cr-Co base metal alloys. This technique involves the deposition of a 6 μm to 8 μm 24 K gold layer directly onto the Cr-Co cast prosthesis framework. The technique improves metal surface properties, making them more biocompatible and usable, however, requires additional equipment and experienced laboratory technicians. Clinical studies should be performed to corroborate the long term success of this technique.

Reliability of mercury-in-silastic strain gauge plethysmography curve reading: Influence of clinical clues and observer variation

Aim. Mercury-in-silastic strain gauge pletysmography (SGP) is a well-established technique for blood flow and blood pressure measurements. The aim of this study was to examine (i) the possible influence of clinical clues, e.g. the presence of wounds and color changes during blood pressure measurements, and (ii) intra- and inter-observer variation of curve interpretation for segmental blood pressure measurements. Methods. A total of 204 patients with known or suspected peripheral arterial disease (PAD) were included in a diagnostic accuracy trial. Toe and ankle pressures were measured in both limbs, and primary observers analyzed a total of 804 pressure curve sets. The SGP curves were later reanalyzed separately by two observers blinded to clinical clues. Intra- and inter-observer agreement was quantified using Cohen's kappa and reliability was quantified using intra-class correlation coefficients, coefficients of variance, and Bland-Altman analysis. Results. There was an overall agreement regarding patient diagnostic classification (PAD/not PAD) in 202/204 (99.0%) for intra-observer (κ = 0.969, p < 0.001), and 201/204 (98.5%) for inter-observer readings (κ = 0.953, p < 0.001). Reliability analysis showed excellent correlation between blinded versus non-blinded and inter-observer readings for determination of absolute segmental pressures (all intraclass correlation coefficients ≥ 0.984). The coefficient of variance for determination of absolute segmental blood pressure ranged from 2.9–3.4% for blinded/non-blinded data and from 3.8–5.0% for inter-observer data. Conclusion. This study shows a low inter-observer variation among experienced laboratory technicians for reading strain gauge curves. The low variation between blinded/non-blinded readings indicates that SGP measurements are minimally biased by clinical clues.

A comparison of microscopic examination and rapid diagnostic tests used in Guyana to diagnose malaria

The aim of this study was to compare rapid diagnostic tests (RDTs) for malaria with routine microscopy for a prompt and accurate diagnosis of malaria and to provide an effective disease management in Guyana. Blood samples were collected randomly from 624 patients with clinical suspicion of malaria from four private hospitals in Georgetown, Guyana. The five different test methods [Paramax-3, Optimal-IT, VISITECT Malaria Combo PAN/Pf, Standard Diagnostic (SD) Bioline and conventional Giemsa stain microscopy] were performed independently by well trained and competent laboratory staff to assess the presence of malaria parasites. Results from the rapid diagnostic kits were analyzed and compared to those obtained by general microscopy. Of the 624 patients involved in the study, 197 (31.6%) tested positive and 427 (68.4%) tested negative to RDT whereas 190 (30.4%) tested positive and 434 (69.6%) tested negative to microscopy. The positive agreement index between RDT and microscopy was 89%. A comparison of microscopy with the RDTs, Paramax, Opitmal- IT, Omega, SD, showed a positive agreement index of 93%, 86%, 80% and 86%, respectively. The study, therefore, highlights the importance of both methods in diagnosis of malaria in endemic areas. Microscopy is the more reliable method in rural areas where malaria is most prevalent. RDT offers a good alternative, being an easy and rapid method that does not require an experienced laboratory technician.

Schistosomiasis mansoni and soil-transmitted helminthiasis in Bushulo village, southern Ethiopia

Background: Schistosomiasis mansoni and soil-transmitted helminthiasis (STHs) are considerable medical and public health problems in Ethiopia. However, information is limited on the epidemiology of these infections in different localities even though it is needed to plan effective prevention and control measures. Objective: This study was designed to determine the prevalence of Schistosoma mansoni and soil-transmitted helminth infections in school children and residents in Bushulo village near Lake Awassa (Hawassa), southern Ethiopia. Methods: Cross-sectional epidemiological and parasitological studies were conducted on schistosomiasis mansoni and STHs in Bushulo village in May and June 2007. A total of 419 participants (353 school children and 66 other residents) were included in the study. The principal investigator interviewed the study subjects about demographic status using structured questionnaires. Moreover, experienced nurse took history and conducted physical examination to assess symptoms and signs related to chronic S. mansoni infection. A single stool sample was collected from each participant and processed using the Kato-Katz technique. Experienced laboratory technician read all slides at Bushulo Health Center. Results: The overall infection rates of schistosomiasis mansoni, trichuriasis, ascariasis and hookworm infection were 73.7%, 41.5%, 37.2% and 28.4%, respectively. Other parasitic infections observed were caused by Hymenolepis nana (1.7%), Taenia species (1.4%), and Enterobius vermicularis (1.4%). Children in the age range 10-14 years and those attending at St. Paul&rsquo;s School had higher rates of T. trichiura and S. mansoni, respectively. Intensity of infection was higher for A. lumbricoides in the age range 5-9 years. The overall prevalence of any STHs was 67.3%. The rates of single, dual, triple and quadruple infections were 29.6%, 32%, 20.3% and 7.4%, respectively. Conclusion: The high prevalence and intensity of schistosomiasis mansoni and soil-transmitted helminthiasis makes periodic deworming programme urgent to reduce morbidity and transmission of helminthiasis in the area. Provisions of sanitary facilities and clean water supply as well as health education are also critically needed to sustain the impact of chemotherapy.

Comparison of the Flotac-400 Dual Technique and the Formalin-Ether Concentration Technique for Diagnosis of Human Intestinal Protozoon Infection

There is a need for accurate diagnosis of intestinal parasite infections in humans, but currently available copromicroscopic techniques have shortcomings, such as low sensitivity. We compared the diagnostic accuracy of a further modified version of the recently developed Flotac technique with that of the widely used formalin-ether concentration technique (FECT) for the detection of intestinal protozoa in human stool samples. Formaldehyde-preserved stool samples from 108 individuals in Côte d'Ivoire were subjected to the Flotac-400 dual technique, using two different flotation solutions (FS), and to the FECT. Stool samples were examined according to computer-generated random lists by an experienced laboratory technician blinded for the results of each method. Both methods detected the same eight intestinal protozoon species. While the Flotac-400 dual technique (results from both FS combined) found higher prevalences of Entamoeba coli (77.8% versus 71.3%, P < 0.001), Blastocystis hominis (20.4% versus 13.0%, P = 0.458), and Giardia intestinalis (8.3% versus 6.5%, P < 0.001), the FECT detected higher prevalences of Entamoeba histolytica/Entamoeba dispar (27.8% versus 20.4%, P = 0.019) and four species of nonpathogenic intestinal protozoa. The diagnostic agreement between the two methods differed considerably depending on the intestinal protozoon investigated (Cohen's kappa measures; range, 0.01 to 0.46). Our study confirmed that the Flotac-400 dual technique can be utilized for the diagnosis of intestinal protozoon infections in humans. Since Flotac is a sensitive technique for the detection of soil-transmitted helminths and Schistosoma mansoni, it might become a viable copromicroscopic technique for the concurrent diagnosis of helminths and intestinal protozoon infections.

Fusobacterium necrophorum– detection and identification on a selective agar

Within the last decade, Fusobacterium necrophorum subsp. funduliforme has been considered a clinically important pathogen causing pharyngitis especially in adolescents and young adults. F. necrophorum pharyngitis can progress into Lemierre's syndrome, which is a severe and life-threatening infection. However, throat swabs are not cultured anaerobically in the routine and even if cultured anaerobically, it can be difficult to identify F. necrophorum from the normal flora of the throat. F. necrophorum is therefore often overlooked as the cause of pharyngitis. In our laboratory, a F. necrophorum selective agar has been developed containing vancomycin and nalidixin, which inhibit the growth of most Gram-positive and many Gram-negative bacteria, respectively. β-haemolysis of horse blood can be detected, which further facilitates the detection and identification of F. necrophorum. The F. necrophorum selective agar was evaluated against a quantitative real-time polymerase chain reaction assay and shown to have a significantly higher sensitivity for detecting F. necrophorum than the anaerobic agar commonly used in Denmark. Furthermore, the F. necrophorum selective agar does not require experienced laboratory technicians, require fewer subcultures, is probably less expensive and is faster to perform than other culture methods.

Succinylcholine-induced Hyperkalemia and Beyond

The mechanism of succinylcholine-induced hyperkalemia was studied in three lesions affecting canine gastrocnemius muscle. Dogs were treated for 1 month before study: 10 with normal activity, 5 with unilateral sciatic nerve section, active on 3 legs, 5 with unilateral cast immobilization of a hind limb and pelvis, active on 3 legs, and 7 inactive with T6 section of the spinal cord. Succinylcholine responses were determined during thiopental―ha lothane (mean expired halothane 1.0 ± 0.2%) endotracheal anesthesia with arterial carbon dioxide tension of 38—42 mmHg, arterial oxygen tension of 100—120 mmHg, and muscle and body temperatures maintained at 37° ± 0.2°C. The investigators isolated and collected the venous drainage of gastrocnemius muscle and measured its total blood flow. Muscle potassium release and oxygen consumption were calculated as blood flow x (arterial content — venous content). Succinylcholine-induced gastrocnemius potassium release was greatest after both sciatic and cord section; oxygen consumption was increased in parallel. Disuse atrophy of one leg slightly increased both values but was insufficient to produce systemic hyperkalemia. Reuptake of potassium followed succinylcholine-induced release. Given before succinylcholine, modest doses of gallamine slightly modified the release of potassium, and total paralysis by gallamine blocked it.

Validation of the Hemo_Control instrument for determination of B-haemoglobin concentration in primary health care

Objective: The aim of this study was to evaluate the analytical performance of a new portable haemoglobinometer, Hemo_Control (EKF-diagnostic, GmbH, Germany), which measures haemoglobin concentration in venous and capillary samples. Method: The within series and between series imprecision of the Hemo_Control instrument were calculated after measuring the concentration of venous samples under standardized conditions; by experienced laboratory technicians in a hospital laboratory, and venous and capillary samples under conditions similar to where the instrument is intended for use; by personnel at two primary health care centres. The bias of the Hemo_Control instrument was calculated as the difference between its results and results obtained with a Coulter LH 750 instrument traceable to the ICSH reference method. Results: The uncertainty of the Hemo_Control instrument for venous samples was lower than the quality goal of ± 5% considered acceptable for patient care. High within series imprecision (5.5%) was observed for measurements of capillary blood samples in one of the primary care centres, whereas adequate analytical performance was obtained at the other centre. The Hemo_Control instrument showed negligible bias of +0.8 g/L for both venous and capillary samples in primary health care. Conclusion: The observed uncertainty indicates that Hemo_Control is appropriate for near patient testing using venous samples. Capillary samples may be used if sampling skills are adequate.