Proven Diagnostics Test Catalog

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ACTIVATED PARTIAL THROMBOPLASTIN TIME
Test code:
 APTT
Specimen type:
 Platelet-free plasma.
Tube type / collection container:
Specimen collection notes:
 Do not draw blood from a heparinized line. Avoid contaminating the sample with tissue thromboplastin or heparin. Venipuncture must be performed with no trauma. Hemolyzed samples are not acceptable. If blood is drawn from an indwelling catheter, flush with 5 mL of saline and discard the first 5 mL of blood collected. NOTE: Test sample cannot be hepasorbed if patient is on therapeutic heparin therapy.
What to submit:
1 mL aliquot plasma.
Patient preparation:
 None.
 
Specimen Processing Instructions:
Centrifuge the citrated blue-top tubes as soon as possible (within 60 minutes) for 15 minutes at 1500 x g to obtain platelet-poor plasma (<10,000 µL). Using a plastic pipette, remove 1 mL of plasma and transfer to a plastic aliquot tube and label with patient's name and a second patient identifier (e.g., date of birth, medical record number).
Transport temperature:
 Frozen.
Specimen stability:
 Stable 4 hours at room temperature.
Rejection criteria:
 Clotted specimen. Hemolyzed specimen. Underfilled or overfilled tubes.
 
Reference range:
 23-35 seconds.
Alert limits:
 Greater than 120 seconds.
Additional information:
 None.
CPT code(s):
 85730
Note: The billing party has sole responsibility for CPT coding.  Any questions regarding coding should be directed to the payer being billed.  The CPT codes provided are based on AMA guidelines and are for informational purposes only.
When performed:
 Monday-Friday
Test includes:
 APTT.
Methodology:
Mechanical Clot-Based
Synonyms:
PTT, PARTIAL THROMBOPLASTIN TIME, APTT
Clinical Significance:
Prolongation of the APTT test may be due to deficiencies or inhibitors of factors in the coagulation system. The APTT test is also used for monitoring the dosing effect of theraeputic unfractionated heparin.