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HelpProthrombin Time INR
Additional Codes
LAB320
Performing Laboratory
MBMC Main Laboratory
Methodology
Absorbancy measurement, Clot signature formation
Includes international normalized ratio (INR) and PT.
Literature References:
Package insert: RecombiPlasTin 2G determination of prothrombin time by ACL TOP, Instrumentation Laboratory, June 2012.
Specimen Requirements
Specimen must arrive within 24 hours; once opened, specimen is stable for 4 hours.
Specimen Type: Plasma
Container/Tube: 2.7-mL, light-blue top (sodium citrate)
Specimen Volume: Full tube
Specimen Minimum Volume: Fill to frosted minimal fill line on the tube.
Pediatric 1.0 mL in special pediatrics collection tube- 3.2% sodium citrate. The tube has no vacuum.
Collection Instructions: It is imperative that the tube be completely filled to maintain the proper ratio of blood to anticoagulant.
Specimen Transport Temperature
Ambient/Refrigerate NO/Frozen NO
Day(s) Test Set Up
Monday through Sunday
Turnaround Time:
STAT: 1 hour after receipt in laboratory
Routine: within 4 hours
Reference Values
PT: 9.7 - 13.0 seconds
INR: 0.90 - 1.20
INR: Critical value (automatic call-back): >5.00
| INR Indication | INR Target |
| Orthopedic | |
| Total Hip and Knee Arthroplasty | 1.8 to 2.6 |
| Hip Fracture | 1.8 to 2.6 |
| Cardiology | |
| Atrial Fibrillation | 2-3 |
| Cardiomyopathy | 2-3 |
| Myocardial Infarction | 2.5-3 |
| Non-native Valves | 2-3.5 |
| Treatment of Venous Thrombosis | |
| Deep Vein Thrombosis | 2-3 |
| Pulmonary Embolism | 2-3 |
Test Classification and CPT Coding
Test Classification:This test has been cleared or approved by the U.S. Food and Drug Administration and is used per manufacturer’s instructions.
CPT Code:
85610
Stability
24 hours at 18oC to 24oC if the sodium citrate tube is unopened (capped)
4 hours at 18oC to 24oC after the sodium citrate tube has been opened (uncapped)