Effect of Pre-Analytic Variables on Prothrombin Time and Activated Partial Thromboplastin Time

Anandani, Garima M; Parikh, Swati B

doi:10.7860/jcdr/2018/32666.11719

Cited by 2 publications

(1 citation statement)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Studies analyzing hemolysis interference with coagulation tests are not numerous nor comparable between each other due to different methodologies and sample patient size (3). Mainly, hemolysis technics used in these studies are: use of deionized water with or without detergents for whole anticoagulated samples lysis, freezing and thawing whole anticoagulated blood ( 13), spiking plasma with hemolysate products, and mechanical lysis by stirring with a metallic bar, sonication, application of the blade of a tissue homogenizer (7,14) and aspiration using a differ-ent diameter needle than the recommended one (3,5,(14)(15)(16)(17).…”

Section: Discussionmentioning

confidence: 99%

Hemolysis has no influence on routine coagulation tests in subjects without anticoagulant therapy - a referral Romanian emergency hospital laboratory experience

Binzari

Zaharia

Barbu

et al. 2019

Revista Romana De Medicina De Laborator

View full text Add to dashboard Cite

The aim of this study was to determine the rate of hemolyzed specimens sent to our laboratory for coagulation testing, assess the interference of hemolysis on coagulation for patients without anticoagulant therapy and to determine the reference intervals for PT, INR and aPTT for our laboratory in order to test our own limitations. Methods: To determine the hemolysis rate, 1,689 specimens were evaluated on a visual scale and with the hemolysis icterus lipemia (HYL) test on Architect c4000 instrument. 125 blood samples collected from subjects without anticoagulant therapy were hemolyzed in vitro and the PT, INR and aPTT results were compared before and after hemolysis.To determine reference intervals (RI) for PT, INR and aPTT in our population, 125 apparently healthy human subjects (according to CLSI C28-A2) were enrolled and tests were performed on Sysmex CS 2000i, using Siemens reagents. Results: Out of 1,689 samples, 9.46% were assessed as hemolyzed by the visual scale, while HYL test showed a 6.63% hemolysis rate. We found a shortening of 0.1s for PT, a diminution with 0.01 units for INR and a prolongation with 0.9s for aPTT from in vitro hemolyzed compared to non-lyzed samples. As to the reference intervals, we obtained in our laboratory versus reagents producer: for PT 9.8-13.9 s vs 9.8-12.1 s, and for aPTT 19.1-31.5s vs 23-31.9 s respectively; 28.38% more PT results and 13.44% more aPTT results were within range when we used local laboratory RI, compared to the manufacturer’s RI. Conclusions: The rate of hemolyzed coagulation samples in our laboratory is higher than the rate found in the literature. Nevertheless, for patients without anticoagulant therapy hemolyzed samples should be processed. Using our own reference interval leads to a significant reduced number of abnormal results.

show abstract

Section: Discussionmentioning

confidence: 99%

Hemolysis has no influence on routine coagulation tests in subjects without anticoagulant therapy - a referral Romanian emergency hospital laboratory experience

Binzari

Zaharia

Barbu

et al. 2019

Revista Romana De Medicina De Laborator

View full text Add to dashboard Cite

show abstract

Frozen/Thawed Samples Can Replace Fresh Samples for Assignment of ISI to Secondary Thromboplastin Standards for Multiple Reagent/Instrument Combinations: Data to Support Possible Revision of WHO Guidelines

Kitchen,

Bryant,

Brown

et al. 2024

Int J Lab Hematology

View full text Add to dashboard Cite

BackgroundCalibration of thromboplastins is required for accurate calculation of the international normalised ratio (INR). Accurate INR results are required for optimal dosing of vitamin K antagonists. Decreases in vitamin K antagonist usage have made the recruitment of sample sets for international sensitivity index (ISI) calibrations more difficult. A possible solution to this would be to allow the use of frozen–thawed samples in place of fresh plasmas in the calibration of secondary standards.ObjectivesWe investigated the effect of freezing and thawing samples before usage in ISI calibrations of secondary standards.MethodsMultiple reagent/instruments were tested to identify the degree of difference between a fresh sample ISI calibration and one performed on frozen–thawed samples. Where possible, the two ISI calibrations were performed on the same sample set. Alternatively, a separate set of samples from different patients was used.ResultsThe difference in ISI values was <3% for those datasets where the same samples were used, and <6% for those datasets where two sample sets were used. Additionally, other parameters required for a valid ISI calibration showed only minor differences—some calibrations showed fewer outliers in the frozen–thawed datasets. Mean normal prothrombin time for the international reference thromboplastins was <3.5% different across four different calibrations (two for rabbit thromboplastin and two for recombinant human thromboplastin).ConclusionsThis modification to the WHO guidelines would facilitate the recruitment of test plasmas in advance of calibration solving the problem of requiring availability of fresh patient samples with a range of INRs in a 5‐h window.Trial Registration: Not a part of any clinical trial.

show abstract

Effect of Pre-Analytic Variables on Prothrombin Time and Activated Partial Thromboplastin Time

Cited by 2 publications

References 0 publications

Hemolysis has no influence on routine coagulation tests in subjects without anticoagulant therapy - a referral Romanian emergency hospital laboratory experience

Hemolysis has no influence on routine coagulation tests in subjects without anticoagulant therapy - a referral Romanian emergency hospital laboratory experience

Frozen/Thawed Samples Can Replace Fresh Samples for Assignment of ISI to Secondary Thromboplastin Standards for Multiple Reagent/Instrument Combinations: Data to Support Possible Revision of WHO Guidelines

Contact Info

Product

Resources

About