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Test ID: D-Dimer
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D-Dimer
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Useful For
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Diagnosis of intravascular coagulation and fibrinolysis (DIC), especially when combined with clinical information and other laboratory test data (e.g., platelet count, fibrinogen assay, prothrombin time and activated partial thromboplastin time).Along with the physician's pretestprobapility assessment D.Dimer level at a specific cut off can be used to exclude the diagnosis of acute pulmonary embolism or DVT.
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Method name and description
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Turbidimetric Immunoassay.
Test is performed using different analyzer platforms.
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Clinical information
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Increased levels of D-Dimer are found in various conditions including:
- Deep vein thrombosis (DVT)
- Pulmonary Embolism (PE)
- Disseminated Intravascular Coagulation (DIC)
- Post-surgery.
- Cancer Cases.
- Liver Cirrhosis.
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Specimen type / Specimen volume / Specimen container
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Plasma Na Cit. Plasma poor platelets.
Specimen Volume:2.7 ml.
Container/Tube: Light-blue top (3.2% sodium citrate).
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Collection instructions / Special Precautions / Timing of collection
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1- Sample collected in HMC facilities/others and transported to the lab within 1hour :
• Collect sample into light blue-top (sodium citrate).
• Tubes must be filled to within +/- 10% of their proper volume, to provide a 9:1 ratio of blood to citrate.
2- Samples collected in HMC facilities / others and which are expected not to reach the lab within 1hour:
• Centrifuge the whole blood and carefully remove the plasma by pipette not by decanting and send the plasma in a temperature-controlled environment (18-25ºC ) within one hour of centrifugation.
• If the transportation of the plasma can’t be within a maximum of 2hour , prepare platelet-poor plasma as follow:
A: Re-centrifuge plasma again.
B: Remove the top portion of plasma leaving approximately 250 mcL in the bottom to discard.
C: The double-centrifuged plasma should be aliquoted (0.5 to 1 mL per aliquot) into labeled plastic tubes. The number of tests ordered will determine the aliquots needed.
D: Freeze immediately at -20 ºC or below .
E: Specimens must arrive frozen.
3- Sample for Platelets function studies (Platelets function assay) , Citrated whole blood should reach HMC within a maximum of 1-2 hours of collection.
4- For heparin monitoring, follow the above mentioned steps.
5- Consider patient HCT %. , if HCT >55%, the volume of anticoagulant in the tube must be adjusted by the referring lab, as per the below table shows the volume of citrate (µL) to be removed from common sizes of coagulation specimen tubes prior to specimen collection. After removal of the specified volume of citrate, enough blood is added to fill the tube to the ideal volume.
| HCT% |
Volume to be removed, µL |
| 2.7 ml Tube |
1.0 ml Tube |
| 56 |
50 |
20 |
| 57 |
50 |
20 |
| 58 |
60 |
20 |
| 59 |
60 |
20 |
| 60 |
70 |
30 |
| 61 |
70 |
30 |
| 62 |
80 |
30 |
| 63 |
80 |
30 |
| 64 |
90 |
30 |
| 65 |
90 |
30 |
| 66 |
100 |
40 |
| 67 |
100 |
40 |
| 68 |
110 |
40 |
| 69 |
110 |
40 |
| 70 |
120 |
40 |
| 71 |
120 |
40 |
| 72 |
130 |
50 |
| 73 |
130 |
50 |
| 74 |
140 |
50 |
| 75 |
140 |
50 |
| 76 |
150 |
50 |
| 77 |
150 |
60 |
| 78 |
160 |
60 |
| 79 |
160 |
60 |
| 80 |
170 |
60 |
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Relevant clinical information to be provided
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Patient/family history of thrombotic disorder. History of chronic diseases.
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Storage and transport instructions
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Specimen Rejection Criteria
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Specimens with no label or missing required identification
Broken, leaking or contaminated specimen
Clotted samples
Under-filled or overfilled sample tubes.
Wrong sample container sample received
Improper specimen transport temperature (e.g. like specimens which are needed to be sent on ice)
Old specimen (test-dependent)
Grossly Hemolyzed sample (test-dependent)
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Biological reference intervals and clinical decision values
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The DLMP laboratories use a number of different platforms for this test. Please refer to the below:
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Facility
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Platform
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Reference range
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QRI, NCCCR, RRC-Lab, HMGH, AWH and ABHA
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ACL TOP
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Reference range :0.0-0.49 mg/L FEU
* D‐Dimer test has been cleared by the Food and Drug Administration (FDA) to exclude Venous Thromboembolism (VTE) and pulmonary embolism (PE) at a cut‐off of 0.46 mg/LFEU in patients where a physician's Pretest Probability assessment (PTP) indicates a non‐high probability of pulmonary embolism. (<0.46 mg/LFEU is considered negative).
*If D‐Dimer test is used for clinical conditions other than exclusion of Venous Thromboembolism (VTE) or pulmonary embolism (PE), then the test should be used as an aid in the diagnosis.
The reference range and cut-off value are quoted from Reagent instructions for use (IFU) provided by manufacture .
The reference range is verified by the lab.
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AKH and Cuban
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Sysmex
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Reference Range: 0 - 0.46 mg/L FEU
* D-Dimer test has been cleared by the Food and Drug Administration (FDA) to exclude Venous Thromboembolism (VTE) and pulmonary embolism (PE) at a cut-off of 0.50 mg/LFEU in patients where a physician's Pretest Probability assessment (PTP) indicates a non-high probability of pulmonary embolism. (<0.50 mg/LFEU is considered negative).
*If D-Dimer test is used for clinical conditions other than exclusion of Venous Thromboembolism (VTE) or pulmonary embolism (PE), then the test should be used as an aid in the diagnosis.
The reference range is established by lab.
The cut-off value is quoted from Reagent instructions for use (IFU) provided by manufacture.
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Factors affecting test performance and result interpretation
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The following substances may potentially interfere with the DD HS-up to :
Triglycerides : 15 mmol/L
Hemoglobin : 0.5 g/dL
Bilirubin: 307.8 umol/L
Vary according to the platform used for processing the test.
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Turnaround time / Days and times test performed / Specimen retention time
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Stat:1 hour.
Routine:4 horrs/Daily/NA
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