Home
HelpTest Code PT Prothrombin Time
Additional Codes
LAB320
Performing Laboratory
Central Peninsula Hospital
Collection Instructions
Properly filled 9:1 ratio (blood to anticoagulant); 3.2% NaCitrate tube
Collection Method
Venipuncture
Container
Light Blue Sodium Citrate
Specimen Type
Preferred
- 2.7mL Lt. Blue (3.2% NaCitrate)
Acceptable
- 1.8 mL Lt. Blue (3.2% NaCitrate) tube
Minimum Volume
0.5 ml of plasma from a properly filled 1.8 mL or 2.7 mL NaCitrate (light blue) tube
Specimen Stability
| Ambient (18°C to 24°C) | 8 hours |
| Refrigerated (4°C to 8°C) | N/A |
| Frozen(-70°C to -20°C) | 2 weeks at -20°C; 6 months at -70°C |
Reference or Target Ranges
11.5-15.2 seconds
Report Comment:
INR Interpretation:
• Standard warfarin therapeutic range: 2.0–3.0
• High-intensity warfarin range: 2.5–3.5
Reportable Units
Seconds
Critical Value
INR ≥ 6.0
Reasons for Rejection
| Hemolysis Threshold | N/A |
| Icterus Threshold | N/A |
| Lipemia Threshold | N/A |
| Interfering Subtances/Other | Short draws, over draws, clotted, improperly labeled |
Performance Information
| Days and Time Performed | 24/7 |
| Expected Turn Around Time |
Stat:within 1 hour of arrival to lab Routine: within 4 hours of arrival to lab |
| Stat Availability | Yes |
| Performing Bench | CPH Coagulation |
| Methodology/Method Description | Stago STA Compact MAX |
CPT Codes
85610
Last review/edit date
2025