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Chronometric vs. Structural Hypercoagulability
Carmen Delianu1,2, Mihaela Moscalu3, Loredana Liliana Hurjui2,4
1Department of Biochemistry, "Grigore T. Popa" University of Medicine and Pharmacy, 700115 Iasi, Romania.
Medicina (Kaunas, Lithuania)
|December 31, 2020
Summary
Prolonged tourniquet stasis can falsely shorten prothrombin time (PT) tests, suggesting hypercoagulability. Repeating the PT test from the same sample helps identify and correct these false results, improving patient safety.
Area of Science:
- Clinical Hematology
- Laboratory Medicine
- Diagnostic Testing
Background:
- Prolonged tourniquet stasis during venepuncture can release tissue factor (TF).
- In vitro TF can activate coagulation, leading to falsely decreased prothrombin time (PT) results.
- This can mimic a hypercoagulable state, potentially leading to misdiagnosis.
Purpose of the Study:
- To identify shortened PT tests indicative of potential hypercoagulability.
- To compare initial shortened PT results with those obtained after repeating the analysis from the same sample.
- To assess the impact of test duplication on the accuracy of PT measurements.
Main Methods:
- Analysis of 544 coagulation samples over 4 months.
- Identification of samples with PT results below the normal reference range.
- Comparison of initial PT results with repeat PT measurements from the same sample.
Main Results:
- Out of 544 samples, 36.76% (200) showed corrected PT values upon repeat testing (p=0.001).
- 63.24% (344) of samples continued to indicate a hypercoagulable state after repeat testing.
- A significant proportion of initially shortened PT tests were found to be false positives.
Conclusions:
- Repeating PT determinations can help identify and exclude false hypercoagulability caused by in vitro factors.
- Accurate interpretation of PT results requires correlation with the patient's clinical condition.
- Implementing repeat testing improves laboratory service quality and enhances patient safety by preventing misdiagnosis of hypercoagulability.
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