Tests Included

International Normalized Ratio (INR)

Performed

Daily

Methodology

Clotting Assay

Reported

Routine: 4 hours
Stat: 1 hour

Synonyms

  • Protime
  • Protime with INR
  • PT with INR
  • PT INR
  • International Normalized Ratio
  • Coagulation Pathway
  • Coagulation Lab

Performing Lab

Coagulation

Add-on Eligibility

Yes, within 4 hours of collection if stored at room temperature

Specimen Type

Blood

Specimen Volume

Adult: 2.7 mL (Minimum: 2.7 mL)
  • Light-Blue Top Vacutainer must be completely filled
Pediatric: 1.8 mL (Minimum: 1.8 mL)
  • Translucent Light-Blue Top Vacutainer must be completely filled
Infant / Newborn: 1.8 mL (Minimum 1.8 mL)
  • Use adjusted anticoagulant tube provided by the Coagulation Lab

*This refers to specimen volume at collection prior to any processing

Collection Container

2.7 mL Buffered Sodium Citrate Tube (Light-Blue Top Vacutainer)


OR

1.8 mL Buffered Sodium Citrate Tube (Translucent Light-Blue Top Vacutainer)
  • Call the Rapid Response Coagulation Lab to request this tube
    • The lab will supply an adjusted anticoagulant tube for patients with a hematocrit > 55

Pediatric Collection

1.8 mL Buffered Sodium Citrate Tube (Translucent Light-Blue Top Vacutainer)
  • Call the Rapid Response Coagulation Lab to request this tube
    • The lab will supply an adjusted anticoagulant tube for patients with a hematocrit > 55

Unacceptable Conditions

  1. Hemolyzed or Clotted Specimens
  2. Improper Line Draw
  3. Hematocrit > 55 (Unless a tube with adjusted anticoagulant is used)
  4. Partially-filled tubes
  5. Unlabeled or mislabeled specimens

Storage/Transport Temperature

Transport Instructions    
Collection Location Transport Temperature Processing Required Timeframe
ED/Inpatient Room Temperature None Specimen must be received by the lab within 4 hours of collection
Laboratory/
Outpatient/
Off-Site		 Room Temperature None Specimen must be received by the lab within 4 hours of collection
Frozen at -70°C
(Dry Ice)		 Centrifuge, separate from cells. Repeat twice.
Send double-spun plasma aliquot.		 Specimen must be received by the lab within 6 months of collection

Storage: Plasma must be frozen at -70°C if not tested within 4 hours

Stability (from collection to initiation)

Stability:
Prior to separation from cells:
  • Room Temperature: 4 hours
After separation from cells:
  • Frozen at -70°C: 6 months
    • Samples must be double-spun to remove all platelets before freezing

Laboratory Storage: Room Temperature
Laboratory Retention: 24 hours

Collection Instructions

Labeling Instructions:
  1. When labeling blood tubes, leave a small window visible for the lab to assess the fill volume and sample integrity.
  2. Ensure that the barcode is in the correct orientation.

Collection Instructions:
  1. If blood is to be drawn from an indwelling catheter, the line should be flushed with saline, and the first 5 mL of blood discarded or used for other laboratory tests.
  1. Follow the correct order of draw when collecting with additional orders and tube types:
      
 
  1. Use the BD Vacutainer Plus Plastic Citrate Tube Draw Volume Guide to ensure adequate volume.

    Processing Instructions:
    1. Ensure that the collection tube fill volume is sufficient
    2. Invert the collection tube according to the number of inversions in the chart above
    3. If the specimen will not be received by the lab within 4 hours for testing, prepare and send a double-spun aliquot. To prepare a double-spun aliquot:
    • Centrifuge and separate plasma from cells
    • Centrifuge the plasma aliquot and separate plasma from cells a second time

    Reference Interval

    9.7 - 12.5 seconds

    Interpretive Data

    For patients who are on oral anticoagulant therapy, the recommended International Normalized Ratio (INR) is:
    • INR = 2.0 - 3.0 for most patients
    • INR = 2.5 - 3.5 for patients with mechanical prosthetic heart valves
    Ordering

    Tests Included

    International Normalized Ratio (INR)

    Performed

    Daily

    Methodology

    Clotting Assay

    Reported

    Routine: 4 hours
    Stat: 1 hour

    Synonyms

    • Protime
    • Protime with INR
    • PT with INR
    • PT INR
    • International Normalized Ratio
    • Coagulation Pathway
    • Coagulation Lab

    Performing Lab

    Coagulation

    Add-on Eligibility

    Yes, within 4 hours of collection if stored at room temperature
    Collection

    Specimen Type

    Blood

    Specimen Volume

    Adult: 2.7 mL (Minimum: 2.7 mL)
    • Light-Blue Top Vacutainer must be completely filled
    Pediatric: 1.8 mL (Minimum: 1.8 mL)
    • Translucent Light-Blue Top Vacutainer must be completely filled
    Infant / Newborn: 1.8 mL (Minimum 1.8 mL)
    • Use adjusted anticoagulant tube provided by the Coagulation Lab

    *This refers to specimen volume at collection prior to any processing

    Collection Container

    2.7 mL Buffered Sodium Citrate Tube (Light-Blue Top Vacutainer)


    OR

    1.8 mL Buffered Sodium Citrate Tube (Translucent Light-Blue Top Vacutainer)
    • Call the Rapid Response Coagulation Lab to request this tube
      • The lab will supply an adjusted anticoagulant tube for patients with a hematocrit > 55

    Pediatric Collection

    1.8 mL Buffered Sodium Citrate Tube (Translucent Light-Blue Top Vacutainer)
    • Call the Rapid Response Coagulation Lab to request this tube
      • The lab will supply an adjusted anticoagulant tube for patients with a hematocrit > 55

    Unacceptable Conditions

    1. Hemolyzed or Clotted Specimens
    2. Improper Line Draw
    3. Hematocrit > 55 (Unless a tube with adjusted anticoagulant is used)
    4. Partially-filled tubes
    5. Unlabeled or mislabeled specimens

    Storage/Transport Temperature

    Transport Instructions    
    Collection Location Transport Temperature Processing Required Timeframe
    ED/Inpatient Room Temperature None Specimen must be received by the lab within 4 hours of collection
    Laboratory/
    Outpatient/
    Off-Site    		 Room Temperature None Specimen must be received by the lab within 4 hours of collection
    Frozen at -70°C
    (Dry Ice)    		 Centrifuge, separate from cells. Repeat twice.
    Send double-spun plasma aliquot.    		 Specimen must be received by the lab within 6 months of collection

    Storage: Plasma must be frozen at -70°C if not tested within 4 hours

    Stability (from collection to initiation)

    Stability:
    Prior to separation from cells:
    • Room Temperature: 4 hours
    After separation from cells:
    • Frozen at -70°C: 6 months
      • Samples must be double-spun to remove all platelets before freezing

    Laboratory Storage: Room Temperature
    Laboratory Retention: 24 hours

    Collection Instructions

    Labeling Instructions:
    1. When labeling blood tubes, leave a small window visible for the lab to assess the fill volume and sample integrity.
    2. Ensure that the barcode is in the correct orientation.

    Collection Instructions:
    1. If blood is to be drawn from an indwelling catheter, the line should be flushed with saline, and the first 5 mL of blood discarded or used for other laboratory tests.
    1. Follow the correct order of draw when collecting with additional orders and tube types:
          
     
    1. Use the BD Vacutainer Plus Plastic Citrate Tube Draw Volume Guide to ensure adequate volume.

      Processing Instructions:
      1. Ensure that the collection tube fill volume is sufficient
      2. Invert the collection tube according to the number of inversions in the chart above
      3. If the specimen will not be received by the lab within 4 hours for testing, prepare and send a double-spun aliquot. To prepare a double-spun aliquot:
      • Centrifuge and separate plasma from cells
      • Centrifuge the plasma aliquot and separate plasma from cells a second time
      Result Interpretation

      Reference Interval

      9.7 - 12.5 seconds

      Interpretive Data

      For patients who are on oral anticoagulant therapy, the recommended International Normalized Ratio (INR) is:
      • INR = 2.0 - 3.0 for most patients
      • INR = 2.5 - 3.5 for patients with mechanical prosthetic heart valves

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