PT with INR (Prothrombin Time) and
aPTT (Activated Partial Thromboplastin Time)
Order Name
PT/PTT
Test Number: 1500425
Revision Date 10/08/2024
Test Number: 1500425
Revision Date 10/08/2024
| Test Name | Methodology | LOINC Code |
|---|---|---|
|
Prothrombin Time
|
Clot Detection | 5902-2 |
|
International Normalized Ratio (INR)
|
Clot Detection | 6301-6 |
|
Activated Partial Thromboplastin Time (aPTT)
|
Clot Detection | 3184-9 |
| SPECIMEN REQUIREMENTS | ||||
|---|---|---|---|---|
| Specimen | Specimen Volume (min) | Specimen Type | Specimen Container | Transport Environment |
| Preferred | 1.5 mL | Double Spun Plasma | Sterile, Capped Plastic Tube | Frozen |
| Alternate 1 | 2.7 mL | Whole Blood | Sodium Citrate 3.2% (Blue Top) | Room Temperature |
| Instructions | Please indicate anticoagulant therapy. Each 2.7mL Sodium Citrate 3.2% (Blue Top) tube must be filled to the proper level, no hemolysis. Improperly filled tubes can give erroneous results. Whole blood must be transported to lab immediately. If testing cannot be started within 4 hours of collection the specimen must be double spun then 1.5 mL plasma aliquot from each tube into individual plastic aliquot tubes and freeze. Do not pool aliquots together! Specimen Stability: Un-Frozen specimens are only good for 4 hours. If the patient is on Heparin, Un-Frozen specimens are only good 2hrs. |
|||
| GENERAL INFORMATION | |
|---|---|
| Testing Schedule | Mon-Fri |
| Expected TAT | 1 Day From Set Up |
| Clinical Use | Prothrombin Time (PT) and INR This test is often used to monitor warfarin (coumadin) effect. It may also be used to screen for hemostatic dysfunction involving the extrinsic system as a result of liver disease, vitamin K deficiency, factor deficiency or DIC. Activated Partial Thromboplastin Time (aPTT) This test is most commonly used to monitor heparin therapy. It is also prolonged with deficiencies of clotting factors of the intrinsic system and the common pathway. Presence of antifactor antibodies, and other inhibitors may also be detected with this test. |
| CPT Code(s) | 85730, 85610 |
| Lab Section | Coagulation |