Prothrombin Time (PT) and INR
Order Name
PT
Test Number: 1500350
Revision Date 07/25/2022
Test Number: 1500350
Revision Date 07/25/2022
| Test Name | Methodology | LOINC Code |
|---|---|---|
|
International Normalized Ratio (INR)
|
Clot Detection | 6301-6 |
|
Prothrombin Time
|
Clot Detection | 5902-2 |
| SPECIMEN REQUIREMENTS | ||||
|---|---|---|---|---|
| Specimen | Specimen Volume (min) | Specimen Type | Specimen Container | Transport Environment |
| Preferred | 2.7 mL | Whole Blood | Sodium Citrate 3.2% (Blue Top) | Room Temperature |
| Alternate 1 | 1.5 mL | Double Spun Plasma | Sterile, Capped Plastic Tube | Frozen |
| 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 stability for PT only is 24 hours at Room temperature. If ordering Both PT and PTT and 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! |
|||
| GENERAL INFORMATION | |
|---|---|
| Testing Schedule | Daily |
| Expected TAT | 1 Day |
| Clinical Use | 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. |
| CPT Code(s) | 85610 |
| Lab Section | Coagulation |