1,720,980 research outputs found
Preanalytical variability: the dark side of the moon in laboratory testing
No full textRemarkable advances in instrument technology, automation and computer science have greatly simplified many aspects of previously tedious tasks in laboratory diagnostics, creating a greater volume of routine work, and significantly improving the quality of results of laboratory testing. Following the development and successful implementation of high-quality analytical standards, analytical errors are no longer the main factor influencing the reliability and clinical utilization of laboratory diagnostics. Therefore, additional sources of variation in the entire laboratory testing process should become the focus for further and necessary quality improvements. Errors occurring within the extra-analytical phases are still the prevailing source of concern. Accordingly, lack of standardized procedures for sample collection, including patient preparation, specimen acquisition, handling and storage, account for up to 93% of the errors currently encountered within the entire diagnostic process. The profound awareness that complete elimination of laboratory testing errors is unrealistic, especially those relating to extra-analytical phases that are harder to control, highlights the importance of good laboratory practice and compliance with the new accreditation standards, which encompass the adoption of suitable strategies for error prevention, tracking and reduction, including process redesign, the use of extra-analytical specifications and improved communication among caregivers
Monitoring glycaemic control: is there evidence for appropriate use of routine measurement of glycated haemoglobin?
No full textBackground: Regardless of the available recommendations to perform glycated haemoglobin testing at a 2- to 3-month frequency, there is increasing evidence of an inappropriate laboratory use of this test in clinical practice. Methods: Data from our Laboratory Information System were analysed for glycated haemoglobin test orders over a 3-year period using Microsoft® Excel to calculate the order intervals and the test frequency for each patient. To assess the appropriateness of repeat testing, only data for patients who had at least two separate glycated haemoglobin test results were included in the analysis. Inappropriate test orders were defined as any order for a given patient taking place within a 29- or 89-day period following the previous order. Results: The results of our investigation demonstrate that inappropriate laboratory utilisation of this test is commonplace (26% of total repeat orders within 90 days), especially for inpatients (63.7% of inpatient repeat orders in less than..
Influence of hemolysis on routine clinical chemistry testing
No full textBackground: Preanalytical factors are the main source of variation in clinical chemistry testing and among the major determinants of preanalytical variability, sample hemolysis can exert a strong influence on result reliability. Hemolytic samples are a rather common and unfavorable occurrence in laboratory practice, as they are often considered unsuitable for routine testing due to biological and analytical interference. However, definitive indications on the analytical and clinical management of hemolyzed specimens are currently lacking. Therefore, the present investigation evaluated the influence of in vitro blood cell lysis on routine clinical chemistry testing. Methods: Nine aliquots, prepared by serial dilutions of homologous hemolyzed samples collected from 12 different subjects and containing a final concentration of serum hemoglobin ranging from 0 to 20.6 g/L, were tested for the most common clinical chemistry analytes. Lysis was achieved by subjecting whole blood to an overnight freeze-thaw cycle. Results: Hemolysis interference appeared to be approximately linearly dependent on the final concentration of blood-cell lysate in the specimen. This generated a consistent trend towards overestimation of alanine aminotransferase (ALT), aspartate aminotransferase (AST), creatinine, creatine kinase (CK), iron, lactate dehydrogenase (LDH), lipase, magnesium, phosphorus, potassium and urea, whereas mean values of albumin, alkaline phosphatase (ALP), chloride, γ-glutamyltransferase (GGT), glucose and sodium were substantially decreased. Clinically meaningful variations of AST, chloride, LDH, potassium and sodium were observed in specimens displaying mild or almost undetectable hemolysis by visual inspection (serum hemoglobin <0.6 g/L). The rather heterogeneous and unpredictable response to hemolysis observed for several parameters prevented the adoption of reliable statistic corrective measures for results on the basis of the degree of hemolysis. Conclusion: If hemolysis and blood cell lysis result from an in vitro cause, we suggest that the most convenient corrective solution might be quantification of free hemoglobin, alerting the clinicians and sample recollection. © 2006 by Walter de Gruyter
Serum ferritin as a marker of potential biochemical iron overload in athletes
No full textObjectives: Beyond hematological manipulation, iron supplementation therapy is commonplace in athletes to counterbalance physiological or pathologic anemia and to prevent physiologic dysfunction. However, misuse of iron therapy, occasionally resulting in iron overload, is not free from metabolic risks. Design: We planned to measure baseline serum ferritin concentration in sedentary individual and athletes. Setting: The Institute of Clinical Biochemistry of the Verona University. Participants: Serum ferritin was measured in 60 male healthy sedentary controls, 80 amateur road cyclists, 42 male professional cross-country skiers, and 88 professional male road cyclists. Assessment of Risk Factors: The biochemical iron overload was ascertained by measuring baseline serum ferritin concentration as a reliable approach that mirrors the total body iron content. Main Outcome Measurements: The concentration of serum ferritin in healthy controls was 112 ± 78 ng/mL, whereas that of amateur cyclists, professional skiers, and professional cyclists was 127 ± 76 ng/mL (P = 0.185), 183 ± 130 ng/mL (P = 0.001), and 332 ± 218 ng/mL (P < 0.001), respectively. Results: Both categories of professional athletes showed significantly increased concentrations of serum ferritin, whereas the concentration of amateur cyclists was comparable to that of healthy sedentary controls. Conclusions: Professional endurance athletes have serum ferritin concentrations that are 2-fold to 3-fold higher than those of matched sedentary individuals and amateur athletes, exceeding the threshold for the diagnosis of biochemical iron overload and unveiling potential metabolic risks. Copyright © 2005 by Lippincott Williams & Wilkins
HE4 in ovarian cancer: from discovery to clinical application.
No full textDespite the relatively low prevalence, ovarian cancer is the fifth leading cause of death from cancer among women. As such, an early diagnosis for establishing a timely surgical and/or chemotherapeutic treatment is essential for improving the outcome. The most reliable, but not always straightforward, approach to diagnose ovarian cancer relies on multiple, time-consuming and expensive investigative tools. These typically include clinical presentation (i.e., pelvic or abdominal pain, urinary frequency or urgency, increased abdominal size or bloating) with pelvic examination, transvaginal ultrasonography (US), and measurement of carbohydrate antigen 125 (CA125). Although the conventional pathway to develop and market a clinically useful biomarker is challenging, recent advances in genomic and proteomic technologies have led to the identification of previously unknown candidate markers of ovarian cancer. Some of these are currently under clinical validation. The human epididymis protein 4 (HE4) has recently been approved by the Food and Drug Administration for monitoring recurrence or progression of epithelial ovarian cancer. Nevertheless, reliable clinical evidence demonstrates that HE4, used alone or in combination with CA125, substantially improves the accuracy of screening and/or disease monitoring. This chapter will review the current knowledge on biologic and clinical applications of ovarian cancer biomarkers, with particular emphasis on the newly proposed marker, HE4
National survey on critical values reporting in a cohort of Italian laboratories.
No full textBackground: Critical values' reporting is an essential requisite for clinical laboratories. Local policies were investigated within an indicative cohort of Italian laboratories to monitor the situation and establish a performance benchmark.
Methods: A five-point questionnaire was administered to 150 laboratory specialists attending the SIMEL (Italian Society of Laboratory Medicine) National Meeting in June 2006.
Results: A total of 107 questionnaires (71.3%) were returned with a 100% individual question response rate. Only 55% of the participants acknowledge critical values reporting as an essential practice, 80% admit that a comprehensive list of critical values is unavailable in the laboratory and 4% do not promptly communicate critical values. The list of critical values is variable among laboratories, ranging from none to 20 analytes included. The requesting physician or his/her office staff receives the great majority (97%) of notifications by telephone for outpatients. Critical values for inpatients are notified directly by telephone (81%) and in a minority of cases by either fax or computer (19%). In the inpatient setting, the information is notified to physicians (77%), nurses (15%) or other health-care staff in the clinic (8%). It was found that 49% of the participants adopt a standard (digital or written) policy for routine recording of notifications; in 32% of the cases the registration is left to individual attitudes, whereas in 20% of the cases the notification is not recorded. No laboratory has yet adopted a read-back verification of the complete test result by the person receiving the information.
Conclusions: The importance of critical value reporting is still poorly recognized in Italy and uniform or internationally accredited practices for communication and recording are not currently implemented
Air pollution and sports performance in Beijing.
No full textThe Beijing Olympics will begin in August 2008 and athletes will face an unpredictable challenge. Based on present data, Beijing is one of the most polluted megacities in the world; the air concentrations of carbon monoxide (CO), ozone, nitrogen oxides (NO and NO2), sulphur dioxide (SO2) and particulate matter approach or exceed the current limits established by U. S. Environmental Protection Agency (EPA). Although the athletes who will be competing in Beijing are physiologically very different to the participants in most published studies, and it is therefore difficult to predict individual responses, there is little doubt that the presence of these air pollutants might be detrimental to athletic performance due to the marked increase (up to 20-fold) in ventilatory rate and concomitant nasal and oral breathing. Moreover, mouth breathing often bypasses the noise during strenuous exercise, increasing the deleterious effects of pollutants on health and athletic performance. Although limited, each decrement in athletic performance would have a potentially deleterious impact on top-class athletes competing in the next Olympics in China. Several Olympic records are regularly broken during the Olympics. Will this be the case for Beijing
The holistic approach to teach laboratory medicine.
No full textLaboratory diagnostics has undergone relevant changes in organization and complexity, providing new opportunities and risks. The skill and expertise required for laboratory professionals to fulfil the need of a continuously evolving scenario in diagnostics embrace now a variety of scientific, managerial and organizational issues. Translating into clinical practice new insights from basic science, particularly regarding omics, requires construction of a new and complex core curriculum for laboratory professionals. In addition, the integration of different areas of diagnostics within the same laboratory service is expected to improve efficiency and effectiveness. (C) 2008 Elsevier B.V. All rights reserved
Right or wrong sample received for coagulation testing? Tentative algorithms for detection of an incorrect type of sample.
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