Sign in →

Test Code LAB4256 PT/PTT

Important Note

Fill tube completely to maintain correct Anticoagulant/Blood ratio

Specimen Type

Blue top tube (buffered 3.2% liquid sodium citrate) filled to the indicator with whole blood or Sodium Citrate Plasma removed from cells.

Specimen Volume

3mL Blue top (3.2% Sodium Citrate), or

5mL Blue top (3.2% Sodium Citrate), or

1mL Blue top (3.2% Sodium Citrate) MiniCollect vial, or

500uL (minimum) Sodium Citrate Plasma spun and removed from cells.

Turnaround Time

STAT: 1 hour
Routine: 4 hours

Test Schedule

Daily

Sample Stability

Non-heparin Patients: 4 hours
Patients on heparin: 1 hour. 
Frozen samples are stable for 2 weeks at -20C or 12 months at -70C.

Specimen Processing

Assays of non-heparinized patients must be performed within 4 hours of collection. Assays on specimens suspected to contain unfractionated heparin therapy should be tested within 1 hour of collection.  If time interval between drawing and testing exceeds 1 hour, process sample to create platelet poor plasma, separate into plastic tube and freeze at -20C or less. 

Method

Electromechanical

Reference Ranges

PT 11.6 – 14.7 seconds

INR 0.9-1.2

2.0-3.0 Usual oral anticoagulation range.

2.5-3.5 High level oral anticoagulation range.

Synonyms

Prothrombin Time; PT

Test Components

PT, sec; INR.

CPT Codes

85610,85730

Rejection Criteria

Clotted specimens or improperly filled liquid blue top tube.

If a patients Hematocrit is >55% the coagulation tube must have the amount of anticoagulant adjusted. Call the lab for an adjusted tube. (Note: Tubes with anticoagulant adjusted must be drawn in a syringe and filled manually as the tube vacum will be compromised in the process.)