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Davide Giavarina

Publications and source records attributed to Davide Giavarina.

7 recordsLinked to original sources
PubMed2006

National survey on the pre-analytical variability in a representative cohort of Italian laboratories.

BACKGROUND: Owing to remarkable advances in automation, laboratory technology and informatics, the pre-analytical phase has become the major source of variability in laboratory testing. The present survey investigated the development of several pre-analytical processes within a representative cohort of Italian clinical laboratories. METHODS: A seven-point questionnaire was designed to investigate the following issues: 1a) the mean outpatient waiting time before check-in and 1b) the mean time from check-in to sample collection; 2) the mean time from sample collection to analysis; 3) the type of specimen collected for clinical chemistry testing; 4) the degree of pre-analytical automation; 5a) the number of samples shipped to other laboratories and 5b) the availability of standardised protocols for transportation; 6) the conditions for specimen storage; and 7) the availability and type of guidelines for management of unsuitable specimens. The questionnaire was administered to 150 laboratory specialists attending the SIMEL (Italian Society of Laboratory Medicine) National Meeting in June 2006. RESULTS: 107 questionnaires (71.3%) were returned. Data analysis revealed a high degree of variability among laboratories for the time required for check-in, outpatient sampling, sample transportation to the referral laboratory and analysis upon the arrival. Only 31% of laboratories have automated some pre-analytical steps. Of the 87% of laboratories that ship specimens to other facilities without sample preparation, 19% have no standardised protocol for transportation. For conventional clinical chemistry testing, 74% of the laboratories use serum evacuated tubes (59% with and 15% without serum separator), whereas the remaining 26% use lithium-heparin evacuated tubes (11% with and 15% without plasma separator). The storage period and conditions for rerun/retest vary widely. Only 63% of laboratories have a codified procedure for the management of unsuitable specimens, which are recognised by visual inspection (69%) or automatic detection (29%). Only 56% of the laboratories have standardised procedures for the management of unsuitable specimens, which vary widely on a local basis. CONCLUSIONS: The survey highlights broad heterogeneity in several pre-analytical processes among Italian laboratories. The lack of reliable guidelines encompassing evidence-based practice is a major problem for the standardisation of this crucial part of the testing process and represents a major challenge for laboratory medicine in the 2000s.

Automation↗
PubMed2006

Length of erythrocyte sedimentation rate (ESR) adjusted for the hematocrit: reference values for the TEST 1 method.

It is known that the erythrocyte sedimentation rate is related to the erythrocyte concentration in blood. Recently, some authors have proposed a method for estimating the relation between the Westergren erythrocyte sedimentation rate and the erythrocyte sedimentation rate adjusted on an hematocrit of 0.35 L/L. In this study we firstly evaluated in 236 samples the relation between the erythrocyte sedimentation rate measured by the TEST 1 analyzer in samples corrected to 0.35 L/L of hematocrit and the erythrocyte sedimentation rate measured in undiluted samples, and the hematocrit and the hemoglobin concentration, obtaining a multiple correlation coefficient of 0.956; (p < 0.001). Comparison between the corrected for HCT erythrocyte sedimentation rate, measured vs estimated, showed a bias of 0.0 (0.95 CI: -0.98 to 0.98 mm/h) with an agreement limit +/- 14.5 mm/h. Then, the reference intervals for the estimated erythrocyte sedimentation rate at 0.35 L/L of hematocrit were calculated by means of an indirect method (Kairisto), using the one-year stored data (47810 results) in our laboratory database. Our data showed that the erythrocyte sedimentation rate corrected to 0.35 L/L of hematocrit could be estimated by a simple formula using the TEST 1 results; the reference ranges were higher than the reference ranges for uncorrected samples. New reference intervals were needed for an improved evaluation of the patients, and a table of reference intervals for age and sex is presented.

Adolescent↗
PubMed2003

Decision limit for troponin I on ADVIA:Centaur and evaluation of the analytical precision at low concentrations.

Recent guidelines have defined that the decisional cut-off of cardiac troponin (cTn) would recognize "the normal" subjects, and in theory they do not have "measurable" values of cTn. The 99th percentile of this population is chosen as cut-off but using an assay with an analytical CV < 10% at this value. Objectives of this study were to set the decisional limits for cTroponin I (cTnI) measured by the ADVIA:Centaur, and to evaluate the analytical precision around these limits. 120 normal plasma samples were tested for cTnI levels. The 99th percentile defined the decisional level, according to the recent guidelines. The precision was estimated by 10 replicates for 21 samples. The 99th percentile was 0.17 microg/L, with an analytical CV <10%. Since this analytical method achieves the recommended analytical precision, the cTnI decision level for myocardial damage by the ADVIA:Centaur is 0.17 microg/L.

Blood Chemical Analysis↗
PubMed2002

Monitoring high-dose heparin levels by ACT and HMT during extracorporeal circulation: diagnostic accuracy of three compact monitors.

The correct monitoring of heparin therapy and its reversal determines the successful conduct of cardiovascular surgery with extracorporeal circulation (ECC). The activated coagulation time (ACT) and the heparin management test (HMT) are the most frequently used tests in the operating room. Three compact monitors for ACT or HMT are here evaluated. Forty samples were obtained, at 10-min intervals, from eight patients during ECC. The ACT or HMT was immediately performed using: Hemochron juniors ACT, CoaguCeck Pro (ACT) and Rapid Point Coag (HMT). Data were compared between them and with the heparin levels, measured as anti-Xa. The simple least squares linear regression among, respectively, Hemochron Junior ACT, CoaguCeck Pro ACT, Rapid Point Coag HMT and anti-Xa activity were i=452.3, s=15.2, Sy/x=37.5, r=0.18; i=411.9, s=22.1, Sy/x=48.7, r=0.21 and i=479.4, s=9.0, Sy/x=9.3; r=0.41. CoaguCeck Pro ACT results were above the upper detection limit (500 s) in 37 of 40 determinations. The comparison between ACT Hemocron and HMT Rapid Point Coag shows i=35.7, s=0.9, Sy/x=35.4, r=0.68, with a bias of 29.0 s (CI: 17.9-40.1), 95% of agreement between -41.5 s (CI: -60.7 to -22.3) and 99.5 s (CI: 80.4-118.7). Taking a concentration of 2.0 U/ml of heparin to discriminate between high- and low-risk conditions, receiver-operator characteristic (ROC) curve was used to rank the performance of the methods. Areas under the ROC curve+/-SE for Hemochron Junior ACT and Rapid Point Coag HMT were 0.629+/-0.097 and 0.543+/-0.096. The results obtained by HMT appear similar to those obtained by the ACT for monitoring high-dose heparin therapy in patients undergoing ECC. HMT appeared to perform better than ACT in measuring the heparin effect, while the ROC analysis gives a little more accuracy for ACT. Neither of the two methods is able to achieve enough evidence of diagnostic accuracy. Since these tests are widely used, and there are no laboratory alternatives, a real comparison with the outcome of the patients should be helpful for an evidence-based evaluation of these point-of-care tests.

Aged↗
PubMed2002

Internal quality control for erythrocyte sedimentation rate measured by TEST-1 Analyzer.

The TEST 1 is a fully automated analyzer for measurement of the erythrocyte sedimentation rate. This system employs a particular capillary where blood is moved by a special hydrodynamic system. This original method is not able to measure stabilized samples for quality control, probably because stabilized erythrocytes offer a higher resistance to movement into the capillary, giving a distorted sedimentation curve. We evaluated whether the stability of collected EDTA samples, as declared by the producer company, was sufficient to use samples measured the day before as internal quality control samples. We also evaluated whether different tubes could modify the test results between stored and fresh samples. The difference between ESRs measured in fresh and stored samples are non-relevant after 24h and 48h, using both the tubes considered. The agreement between fresh and stored samples was better than that obtained by comparison with the Westergren method and can be used for the internal quality control procedure.

Bias↗