Evaluation of the test results of new vacuum tubes
The evaluation of the results of the tests of new Acti-Fine® vacuum tubes with lithium-heparin and gel (Granat Bio Tech, Russia) for venous blood collection compared with similar reference ones Vacuette (Greiner Bio One, Austria).
The authors
Aleksandr Gilmanov1, Vladimir Gaintsev1, Svetlana Kovalevskaya2
1. Bashkir State Medical University, Ufa, Russia
2. Pavlov State Medical University, St. Petersburg, Russia
1. Bashkir State Medical University, Ufa, Russia
2. Pavlov State Medical University, St. Petersburg, Russia
The analysis of the database of adverse events "MAUDE Inverse Event Report" (2023) revealed a high probability of false overestimation of troponin levels in laboratory tests of blood samples collected into tubes with lithium heparin and gel from various manufacturers. This can lead to a misdiagnosis and a wrong treatment strategy for patients with the symptoms of acute myocardial infarction (AMI). The results of laboratory tests may be influenced by the components of vacuum tubes (VТ) with lithium-heparin and gel. In this regard, it is recommended to validate vacuum systems for measuring the level of troponin as well as other analytes measured in emergency cardiology, which is confirmed by the provisions of ISO.
The validation of new Acti-Fine® VTs with lithium heparin and gel, 13x100 mm, 5 ml, manufactured by Granat Bio Tech LLC, Russia (VT A), by comparing the results of venous blood samples taken into VT A and those taken as reference VTs Vacuette manufactured by Greiner Bio One, Austria (VT B).
The levels of Ca2+, K+, Na+, Cl-, CK-MB, Tn I, creatinine, and urea were measured in the venous blood plasma samples from the patients aged 16-80 years with cardiovascular pathology, including AMI and the condition after cardiac surgery. Venous blood sampling was performed by the experienced nurses at the university hospital (Ufa, Russia). To obtain plasma, VTs with blood were centrifuged in the modes recommended in the accompanying documentation: "Acti-Fine" – 22-25°C, 2500-3000g, 10 min; "Vacuette" – 20-22°C, 1800-2200g, 15 min.
During the validation of the VTs according to the checklist, the visual inspection of the samples was carried out to identify possible inconsistencies (hemolysis, lipemia, ictericity, microclots, fibrin strands). If there were any signs of a preanalytical discrepancy, the samples were excluded from the study. Then the aliquots of the plasma samples from each VT were examined using different analyzers no later than 4 hours after the blood collection. The samples received from one patient were examined on the same analyzer in one download. In total, the level of 8 analytes was measured in 80 plasma samples twice (1280 measurements).
The results were analyzed using the methods of variation statistics to determine the degree of correlation between the results of the research of the venous blood plasma samples from the same patient from different VTs.
During the validation of the VTs according to the checklist, the visual inspection of the samples was carried out to identify possible inconsistencies (hemolysis, lipemia, ictericity, microclots, fibrin strands). If there were any signs of a preanalytical discrepancy, the samples were excluded from the study. Then the aliquots of the plasma samples from each VT were examined using different analyzers no later than 4 hours after the blood collection. The samples received from one patient were examined on the same analyzer in one download. In total, the level of 8 analytes was measured in 80 plasma samples twice (1280 measurements).
The results were analyzed using the methods of variation statistics to determine the degree of correlation between the results of the research of the venous blood plasma samples from the same patient from different VTs.
1. During the preanalytical evaluation of the plasma samples, inconsistencies were noted in 2 out of 40 cases: insufficient amount of plasma in one of the VTs (insufficient blood collection may have taken place while sampling) and mild hemolysis in one parallel pair of the plasma samples in VTs A and B (intravascular hemolysis is a possible reason).
2. The average levels of the measured analytes in the plasma samples of the same patient from VT A and VT B coincided or were close to each other (Pearson's linear pairwise correlation coefficient is from 0.905 to 0.999, which reflects a very high correlation according to the Chaddock scale). The lowest values of the correlation coefficient were observed when measuring unstable analytes that can change during sample preparation (Ca2+, K+, CK-MB, Na+), but in these cases the Pearson correlation coefficient was at least 0.9. The difference in the average values of the same indicator in the series of measurements of the plasma samples from VT A and VT B was very small (< 2%) and had no clinical significance.
2. The average levels of the measured analytes in the plasma samples of the same patient from VT A and VT B coincided or were close to each other (Pearson's linear pairwise correlation coefficient is from 0.905 to 0.999, which reflects a very high correlation according to the Chaddock scale). The lowest values of the correlation coefficient were observed when measuring unstable analytes that can change during sample preparation (Ca2+, K+, CK-MB, Na+), but in these cases the Pearson correlation coefficient was at least 0.9. The difference in the average values of the same indicator in the series of measurements of the plasma samples from VT A and VT B was very small (< 2%) and had no clinical significance.
In the venous blood plasma samples obtained from Acti-Fine® VTs with lithium-heparin and gel and from similar Vacuette VTs taken as reference, there was a coincidence or minimal differences in the results of the analytes, which allows us to recommend using new VTs to determine routine laboratory parameters in emergency cardiology (Ca2+, K+, Na+, Cl-, CK-MB, Tn I, creatinine, urea).
