Prothrombin Time
Label Mnemonic: PT
Epic code: LAB320
Downtime form: A-1a Doctor/Provider Orders - Pathology Core and Specialty Care Nursery
6240 RCP
Collection Medium:
Light Blue top tube 1.8 mL (Na Citrate)
Full draw; 1.8 mL light blue top (mix well). Tube must be at least 90% full.
Rejection Criteria:
Short drawn tube, clot, traumatic tap (excessive hemolysis).
Turn Around Time:
1 hour (upon receipt in laboratory)
Reference Range:
9-12 seconds

INR Critical Reference Value: greater than 3.9
The INR corresponding to the PT is reported to assist in the monitoring of oral anticoagulants. Must be drawn swiftly with a clean venipuncture (no hematoma). Time drawn must be indicated on requisition. A PT can be performed on a sample if it is kept unopened and uncentrifuged at room temperature to be delivered to lab within 12 hours. A special tube from the lab is necessary if the hematocrit is over 55%.

Prothrombin Time may be performed on the same collection tube as Activated Partial Thromboplastin time (aPTT) and Fibrinogen.

Core Lab instrumentation changed from BCS-XP to CS-5100 on 12/16/2019.

This test is also performed in the Iowa River Landing (IRL) clinical laboratory (for specimens drawn at that site).
Optical clot detection.
CPT Code: