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Test Code PTINR Prothrombin Time and INR

EHR Test Codes

  Test Code Test Name
Atlas PT Protime/INR
Cerner PTINR Prothrombin Time and INR

 

Specimen Requirements

Preparation of Patient: 

None

 

Container Type:

Light Blue Top 3.2% Sodium Citrate Tube 4.5 mL, 3.0 mL, 2.7 mL, 2.0 mL, or 1.8 mL

Specimen Type:

Plasma platelet poor

 

Specimen Volume:

Fill tube completely.  Less than 90% filled tubes will be rejected.

 

Special Instructions:

For patients who are difficult access, < 1 year, and/or have a hematocrit > 55.9%; special tubes with an adjusted amount of anticoagulant can be prepared to allow for proper blood/anticoagulant ratio for accurate testing.  Call the Hematology lab at 231-935-6118 to request special tube.

 

Specimen Handling/Transport:

Do not centrifuge.  Do not refrigerate.  Deliver to laboratory immediately.

Transport ambient room temperature.

 

Special Instructions: 

If a specimen cannot be tested within 24 hours of draw, plasma should be removed from the cells and preserved as follows: Spin in a centrifuge verified for platelet-poor plasma preparation, remove plasma to a plastic tube, spin the plasma a second time, then remove plasma to a screw-top plastic  tube and freeze immediately at -20° C. Transport frozen.

 

Specimen Storage/Stability:

Whole blood ambient room temperature 24 hours. 

Double spun plasma aliquot ambient room temperature 8 hours.

Double spun plasma aliquot frozen -20° C 3 months.

 

Specimen Rejection:

Less than 90% filled tubes

Hemolysis

Clotted

Performing Laboratory

Munson Healthcare Laboratories

Priority, Frequency, & Turnaround

Priority:

STAT, ASAP, Non-Emergent

 

Frequency:

24 hours 7 days a week

 

Turnaround:

0 - 1 days

STAT 60 minute from receipt in lab

Methodology

Electromagnetic Mechanical Clot Detection System

Reporting

Reference Range:

11.8 - 14.3 sec  INR 0.9 - 1.1

 

Critical Decision: 

0 years to 21 years ≥ 2.0 INR

21 years and up ≥ 5.0 INR

Note:  Critical values are called to the provider and communicated as critical.  Documentation of the call is recorded in the patient record.

Clinical Significance

A 30% concentration of the factors II, V, VII, & X (extrinsic pathway) is generally enough for the Protime to be normal. A prolonged PT has been observed in congenital or acquired deficiencies of Factors II, V, VII, X, or fibrinogen. The PT may also be prolonged in liver disease (such as cirrhosis and hepatitis), treatment with vitamin K antagonists, disorders of metabolism of vitamin K, fibrinolysis, and DIC. The more common causes of a prolonged Protime include: Warfarin therapy, Heparin, Direct Thrombin Inhibitors, Cogenital or aquired deficiencies of Factor I, II, V, VII, X, or Fibrinogen, Compsumption of factors I, II, & V (DIC), Vitamin K deficiency, Circulating anticoagulants, Liver disease, extended use of broad spectrum antibiotics, herbal remedies such as garlic, ginger, ginko and feverfew.

CPT Code(s)

85610