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HelpTest Code PTT Activated Partial Thromboplastin Time (APTT), Plasma
Additional Codes
LAB325
Aliases
Partial Thromboplastin
Special Collection Instructions
Properly filled 9:1 ratio (blood to anticoagulant); 3.2% NaCitrate tube
Collection Method
Venous Draw; properly filled 9:1 ratio (blood to anticoagulant)
Minimum Volume
0.25 ml of plasma from a properly filled 1.8 mL or 2.7 mL NaCitrate (light blue) tube
Useful For
The activated partial thromboplastin time (PTT) is a basic coagulation screening test for the assessment of congenital and acquired deficiencies of the intrinsic and common pathways (PK, HMWK, factors XII, XI, IX, VIII, X, V, II, I)
Container
Light Blue Sodium Citrate
Preferred Specimen
2.7mL Lt. Blue (3.2% NaCitrate)
Acceptable Specimens
1.8 mL Lt. Blue (3.2% NaCitrate) tube
Reference or Target Ranges
24 - 36.8 seconds
Reportable Units
Seconds
Critical Value
>100 seconds
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 |
Specimen Stability
| Ambient | Plasma – 4 hours – Specimens must be centrifuged within 1 hour of phlebotomy if the patient is theapeutically heparinized. |
| Refrigerated (4°C to 8°C) | N/A |
| Frozen(-70°C to -20°C) | 2 Weeks@ -20°C; 1 year @ -70°C |
Performance Information
| Days and Time Performed | 24/7 |
| Expected Turn Around Time | Routine: within 4 hours of arrival to lab Stat:within 1 hour of arrival to lab |
| Stat Availability | Yes |
| Performing Bench | CPH Coagulation |
| Methodology/Method Description | Stago STA Compact MAX |
CPT Codes
85730
Last review/edit date
Feb 2024