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HelpTest Code PT PT PROTHROMBIN TIME & INR
Performing Location
Collection Instructions
Refer to venipuncture protocol
Fill vacutainer completely.
Room temp if testing will be done within 12 hours of collection.
Refrigerate if testing between 12 to 24 hours from collection.
Tech: Separate and freeze plasma if testing delayed until after 24 hours from collection time
Collection Container
1 Full Light Blue Citrated Plasma vacutainer tube
Specimen Required/Volume
2.0mL
Specimen Type
plasma
Turn-Around Guidelines
Upon arrival daily
Reference Values
PT: 9.4 – 11.4 Seconds
INR: < 1.26
URGENT: > = 4.0
CRITICAL > = 8.0
Method
Photo-Optical clot detection
CPT
85610
LOINC
34528-0
Special Handling
Patient plasma should be tested within 24 hours if stored in an unopened tube at 2-4°C or .at 18-24°C, within two weeks at -20°C and within six months if stored at -70°C..If testing is not complete within 24 hours, the plasma must be removed and frozen. A frost-free freezer should not be used.