Laboratorio Of Chimica Clinica Ed Ematologia

Vicenza, Italy

Laboratorio Of Chimica Clinica Ed Ematologia

Vicenza, Italy
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Evacuated systems for collection of venous blood are integrated systems of medical and in vitro diagnostic medical devices regulated under European Directives and Italian Legislative Decrees. Both Directives and Decrees endorse the requirement that the whole combination of devices, representing an integrated apparatus, must be safe and not impair the specific performance of each single device. According to mandatory requirements, manufacturers must ensure full compatibility between each component of the system, while the users are responsible for verifying the compatibility of different devices in order to avoid potential quality and safety problems. The acquisition of various devices from different manufacturers may lead to combinations that are not validated by manufacturers themselves and are thus expected to be validated and verified by the users to demonstrate that the system remains safe and will not impair the performance of the individual elements. Therefore, the possibility of purchasing different devices separately should be carefully weighted in terms of risk-benefit, taking into consideration the additional costs of the validation/verification process that should be carried out by the potential user. Since preanalytical problems are the major source of errors in the total testing process, the selection and acquisition of close evacuated systems for blood collection should be considered a critical issue for assuring quality, safety and efficiency of the preanalytical phase of laboratory diagnostics and, therefore, of the total testing process.


Giavarina D.,Laboratorio Of Chimica Clinica Ed Ematologia | Filatondi E.,Laboratorio Of Chimica Clinica Ed Ematologia | Zerbato F.,Laboratorio Of Chimica Clinica Ed Ematologia | Scarzello N.,Laboratorio Of Pronto Soccorso E Accettazione Medica | Riboni V.,Laboratorio Of Pronto Soccorso E Accettazione Medica
Biochimica Clinica | Year: 2013

Blood collection through intravenous (IV) catheter is one of the most frequent causes of hemolysis and stress shear is reported to have an important role in that. Aim of this work was to determine whether the hemolysis rate of blood samples drawn through IV catheter may decrease by using 2.5 mL vacuum collection tubes instead of 5 mL tubes, currently in use. Consecutive samples collected at the emergency department to measure potassium using a 18 gauge IV catheter were evaluated for the presence of hemolysis in the 5 mL lithium heparin with separator gel tubes. The same samples were retested in a similar tube with 2.5 mL aspiration volume, collected at the same time. Hemolysis was evaluated spectrophotometrically on Siemens Advia 2400 analyzer as hemolysis index (HI) in the same run on the two types of tubes for the potassium array. Using a 150 HI cut-off, 48 (6%) of the 798 5 mL specimens were hemolysed, with median HI of 278 (95% confidence interval: 228/362, range 153/1146). Using the 2.5 mL tubes, only 6 samples of these 48 had an HI >150 (P <0.0001). On average, the percentage of reduction of HI values was 86% (range, 44/98). These data confirm that shear stress due to the strength of aspiration is an important cofactor of the hemolysis induced by IV catheter. Last generation analyzers require few microliters of sample to perform a lot of tests. The use of tubes with lower filling volume and consequently lower negative pressure could reduce the rate of samples to be rejected for hemolysis that can delay patient care in overcrowded emergency departments.


Although the patient's wellbeing is the primary aim of Laboratory Medicine, great attention should be given to laboratory efficiency, particularly for reagent expenses. Without quantitative data it is difficult for a laboratory manager to know the relationship between the number of assays that theoretically can be performed with a reagent package and the number of produced reports. Many factors can affect these data; for instance, the calibration frequency or the number of repetitions of a sample, the scheduled turnaround time for the assay, the number of samples to run or the reagent stability. In this study, a software for the laboratory warehouse management was used to evaluate the actual yield of reagent packs and to estimate the real cost of measurements. Costs for reagent purchase in a 12-month time period and data of 1440 different product stock movements for issuing 550,000 reports were analyzed for tests ranging from less than 100 to over 250,000 requests/year. The distribution of the calculated yield for reagent packs was between 16.7% and 98.5%, with a median value of 65.5% (confidence interval, 55.0-79.0). On average, the percentage yield for reagent packs rapidly grows in proportion to the number of determinations performed up to 10,000 tests per year. For assays with a request number exceeding 10,000 the yield was almost always >80%.


Dall'Olio G.,Laboratorio Of Chimica Clinica Ed Ematologia
Rivista Italiana della Medicina di Laboratorio | Year: 2011

In 1859, Paolo Mantegazza, a young italian physician, went back to Italy from South America where he had been staying for four years. He published a paper on his medical observations on the use of Erythroxylon coca leaves by the people of the places where he stayed an practised medicine. The first major effect he observed in native people chewing a bolus of coca leaves, was the vigour that the juice ingested caused in their body making them capable to tolerate the cold, the lack of food, bad weather, heavy and debilitating works also at considerable altitude. The therapeutic properties of the coca leaves, chewed or taken as an infusion, that were considered more important by Mantegazza were the beneficial effects on digestion and stomach disorders. Furthermore on nervous system the use of coca leaves have remarkable influence, but the matter requires further evidences. Mantegazza reported some cases of excessive use and consequent addiction and the results of the experiment performed on himself after ingestion of rising amounts of coca juice from chewing. The Mantegazza work will be widely mentioned by Sigmund Freud, the famous Austrian neurologist, in his 'Über coca' (1884) concerning the effects of cocaine, an alkaloid extracted from coca leaves by the chemist Albert Niemann in 1859. For his monograph Mantegazza received in 1858 the prestigious Dell'Acqua award and many scientists recognized his merits for the pioneering work regarding the therapeutic effects of Erythroxylon coca leaves. © 2011 Springer-Verlag Italia.


SAH denotes a bleeding between the arachnoid membrane and the pia mater. In the first days following the event, the computed tomography (CT) recognises >95% of SAH; however, this high sensitivity decreases with time. In two-three weeks, the CSF examination for the presence of hemoglobin (or its catabolite, bilirubin) becomes the most sensitive test for SAH diagnosis. Since the presence of hemoglobin in the CSF can be caused by traumatic collection, special attention should be paid to preanalytical conditions. Bilirubin gives a yellow colouring to CSF that can be detected by visual inspection. However, this colouring, also named xantochromia, could not be accurately perceived by the human eye. The 2008 United Kingdom guidelines for SAH diagnosis are based on the spectrophotometric analysis of the CSF that represents at present the reference method. However, this procedure is complex, requires skilled specialists and a sufficient number of cases to maintain the competence. Furthermore, its availability as emergency test can be difficult. This is probably the reason why the vast majority of laboratories continue to evaluate the presence of xantochromia by visual inspection. The automation of the bilirubin measurement on clinical chemistry analysers has been proposed. This method is certainly less accurate than spectrophotometric analysis; however, it can be performed on common analysers and made results available for emergency situations, with a short turnaround time.


Dall'Olio G.,Laboratorio Of Chimica Clinica Ed Ematologia
Rivista Italiana della Medicina di Laboratorio | Year: 2011

In the 19th Century oil of bitter almonds, which contains hydrocyanic acid (prussic acid) in variable percentages, was the cause of accidental and suicidal poisoning because of its widespread use in cosmetics and preparations used in handicrafts. In this paper I report four cases of oil of bitter almonds poisoning taken from the medical journals of that time, three of which had a favourable outcome and one of which was a fatal acute intoxication. In the reports were described in detail the symptoms and the course of the poisoning following pharmacological treatments. The symptoms and some easy laboratory tests for the differential diagnosis of hydrocyanic acid and nitrobenzene intoxication are also reported. The latter substance was frequently used in place of oil of bitter almonds because of its lower price and the fact that its organoleptic properties are almost identical. © Springer 2011.


Carta M.,Laboratorio Of Chimica Clinica Ed Ematologia
Rivista Italiana della Medicina di Laboratorio | Year: 2013

Summary: Measurements of glucose are used worldwide to diagnose diabetes and to identify patients at risk of developing diabetes. Furthermore the glycemia is very important in the management of diabetic patients. For both diagnosis and risk assessment, fixed cutpoints of plasma concentrations are used to classify patients and to make decisions regarding management. For this reason all step in the analytical process require careful attention. Now clinical laboratories achieve an accurate measurement of glucose, but, by contrast, the preanalytical issues surrounding this dosage have not been solved. Especially the instability of glucose in blood introduces errors in the classification of individual patients. This brief review examines the main causes of variability of glucose measurements. © 2013 Springer-Verlag Italia. Parole chiave: Glicemia DiabeteGlicolisiCurva da carico orale di glucosio.


Carta M.,Laboratorio Of Chimica Clinica Ed Ematologia
Rivista Italiana della Medicina di Laboratorio | Year: 2010

In a recent report, an international expert committee recommended the use of HbA1c test to diagnose diabetes and the American Diabetes Association approved the decision. HbA1c has several advantages to fasting plasma glucose, such as greater preanalytical stability, less day-to-day perturbation during periods of stress and illness. Nevertheless, this test has limitations: the presence of hemoglobin variants or any condition that may change red cell turnover will lead to spurious results. Another important change on diabetes management is related to the screening of gestational diabetes. The recent Hyperglycemia and Adverse Pregnancy Outcome (HAPO) study, a large multicenter multinational blinded trial, described a strong continuos association between maternal glucose concentration and increasing birth weight and markers of perinatal complications. The HAPO study used a 2-hour 75 g glucose load with no preliminary screening based on either risk factors or a challenge test. These results have led to careful reconsideration of the diagnostic criteria for gestational diabetes mellitus (GDM).


Fortunato A.,Laboratorio Of Chimica Clinica Ed Ematologia
Rivista Italiana della Medicina di Laboratorio | Year: 2010

Background. At the beginning of eighties human chorionic gonadotropin (hCG) immunoassays availability significatively improved the laboratory role in pregnancy diagnosis. Increased methods sensitivity of blood tests and urine point of care or home pregnancy tests enables not only early pregnancy detection and demonstration of hCG secretion in other physiopathology conditions but also the oversensitiveness to interference mainly for urine samples. Methods. Analytical and interpretative aspects of hCG detection related to the molecular heterogeneity and the need of methods standardization are discussed. To evaluate the performances of six different commercial pregnancy tests we report results obtained in urine samples with hCG concentration between 0 and 2000 IU/L for a total of 500 assays. Results. hCG molecular heterogeneity is due both to structure variants and carbohydrate content, the consequence is the use of nonstandard nomenclature for hCG variants, absence of purified standards to achieve accurate calibration and discrepant characterizations of hCG variants that are recognized by different hCG immunoassays. Our data for the pregnancy test methods comparison demonstrate that all samples, with hCG concentration between 15 and 70 IU/L, showed at least one disagreeing clinical result. Conclusions. With different immunoassays giving different results for the same specimens, hCG measurement standardization is an important problem and recently it has been a topic of great discussion. Also results obtained with urine quick tests aren't always easy to interpret, also if tests are performed by skilled technicians, and often manufacturer declared sensitivity is better than that demonstrated in our study.


Fortunato A.,Laboratorio Of Chimica Clinica Ed Ematologia
Practical Laboratory Medicine | Year: 2016

Objectives: To assess the performance of LIAISON® BRAHMS PCT® II GEN (DiaSorin, Saluggia, Italy) in procalcitonin (PCT) determination by comparing it to the assay reference method B·R·A·H·M·S PCT KRYPTOR (Thermo Fisher Scientific Clinical Diagnostics, Hennigsdorf, Germany) and assessing its ability to discriminate between healthy subjects and patients with suspected infection. Methods: Diagnostic performance was evaluated on: a) 193 selected samples covering the assay range, whose procalcitonin levels were already evaluated with the B·R·A·H·M·S PCT® KRYPTOR; b) prospective samples: 150 apparently healthy specimens obtained from a blood bank, 161 hospitalized patients (not with specific pathologies), 243 apparently healthy children. Results: The comparison of LIAISON® BRAHMS PCT® II GEN to the reference method B·R·A·H·M·S PCT KRYPTOR yielded high correlation coefficients: slope of Deming fit equal to 1.04 (95% CI: 0.99-1.09) with an intercept equal to 0.05 (95% CI: -0.09 to 0.19) and a high concordance (98.4% (95% CI: 95.5-99.7%)) at the 0.5 ng/mL cut-off. Moreover, the results obtained using prospective samples showed: (i) no samples with PCT concentration >0.5 ng/mL (cut-off) for the apparently healthy adults (highest value=0.033 ng/mL, 95th percentile and 97.5th percentile <0.02 ng/mL); (ii) 2 samples >0.5 ng/mL for hospitalized patients (highest value=0.715 ng/mL, 95th percentile: 0.054 ng/mL; 97.5th percentile: 0.088 ng/mL); (iii) 3 samples >0.5 ng/mL for the healthy children population (highest value=0.713 ng/mL, 95th percentile: 0.155 ng/mL; 97.5th percentile: 0.275 ng/mL). Conclusion: The fully automated LIAISON® BRAHMS PCT® II GEN agrees well with the reference method and is suitable for early diagnosis of sepsis, severe bacterial infection and guiding antibiotic therapy. © 2016.

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