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Test Code LAB2312 Partial Thromboplastin Time (PTT), 50:50 Mix, Plasma

Important Note

Test must be in lab within 4 hours of collection.

Additional Codes

LAB2312

Methodology

Absorbance measurement, Clot signature formation
Literature References:
HemosIL SynthASil (pn 20006800) package insert issued 02/2016, Instrumentation Laboratory.

Performing Laboratory

Barnes-Jewish Hospital Laboratory

Specimen Requirements

Specimen Type: Plasma

Container/Tube: Light-blue top (citrate)

Specimen Volume: 2 Full tubes

Specimen Minimum Volume: 2 full tubes

Collection Instructions:

  1. Draw a discard blue top tube prior to drawing a light-blue top (citrated) tube if using a Winged Infusion Set.  Discard tube should be under filled and discarded.
  2. Clotted blood or an insufficient specimen is not acceptable.
  3. Avoid phlebotomy techniques which cause hemolysis and heparin contamination.
  4. Follow nursing policy on volume of blood to discard prior to collecting blood from indwelling heparinized catheters.

Analyte Stability:

4 hours at 18° C to 24° C
Additional Information: If the patient is a hospital patient and the hematocrit is >55%, call Barnes-Jewish Hematology Laboratory at 314-362-5203 for instructions.

Specimen Transport Temperature

Ambient/Refrigerate NO/Frozen NO

Reference Values

28 - 38 seconds (50:50 mix of patient and normal plasma will not correct a prolonged PTT if an inhibitor is present)
Physician alert value (automatic call-back): >150 seconds

Day(s) Test Set Up

Monday through Sunday

Turnaround Time:

STAT: 2 hour after receipt in laboratory

Routine: 2-4 hours after receipt in laboratory

Test Classification and CPT Coding

85730 -PTT activated straight

85732 x 2-PTT activated 50:50

Additional Information

For BJH Laboratory Use Only

Analyte Stability:

4 hours at 18o C to 24° C


Laboratory Processing Instructions:

Test performed in BJH Core Lab.

LOINC Code Information

Name                               LOINC Code

PTT activated straight     14979-9

PTT incubation mix          5946-9

PTT immediate mix          30323-0