Home
HelpProthrombin Time (PT) and INR
Collection Requirements
Source: blood
Container: Sodium citrate light blue
Volume: 2.7 mL in vacutainer filled to the
line
Special Instructions
If patient's hematocrit is >55%, call Hematology for special collection tube
Turn Around Time
STAT: 1 hour
Routine: 4 hours
Availability
STAT
Routine
Lab Processing Instructions
Specimen: plasma
Double spin and separate
Freeze if testing will not be completed within 1 hour of
processing
Offsites:
- STAT: Send plasma at room temperature with a STAT courier
- Routine: Send plasma on dry ice
Performing Laboratory
Adele Hall
Adele Hall Lab Section
Hematology
Instrumentation/Methodology
Stago STAR
Additional Information
INR calculation is based on geometric mean PT for patients
>90-days of age
Interpret INR with caution in infants
Critical Values
INR >5
Reference Ranges
| Age | Reference Range (sec) |
|---|---|
| 0-30 days | 10.8 - 17.0 |
| 31-90 days | 10.8 - 16.2 |
| > 90 days | 11.3 - 15.6 |
CPT
85610