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Test Code 8450 PTT (Partial Thromboplastin Time)

Important Note

Important Note

Test subject to Medicare National Coverage Determination (NCD) 190.16 PTT TESTING

See Medical Necessity on Sidebar

Purpose

The PTT is sensitive to deficiency or inhibition of factors in the intrinsic pathway. These include the contact factors; high molecular weight kininogen (HMWK), prekallikrein, and factor XII along with procoagulant factors XI, IX, VIII. The PTT is less sensitive to deficiencies of X, V, prothrombin, and fibrinogen.

 

Performing Laboratory

Copley Hospital

 

Methodology

Photo-Optical

 

Specimen Requirements

Specimen Type: Blood (Plasma)

Container/Tube: Light-Blue Tube

Specimen Volume: Full Tube

Specimen Minimum Volume: Full Tube

 

Collection Instructions: 

1. If using a butterfly collection set up, draw a waste tube

     first before the coagulation tube.

2. Label specimen with patient’s full name, date of birth,

    date & time of collection, and person collecting.

3. Keep specimen at room temperature during transport.

 

Reference Values

Normal:         24 - 32 Seconds

                         40.3-55.9 Seconds for Therapeutic Cardiac

Critical:          > 100 Seconds

 

Stability

Room Temperature:             1 Hour After Collection if on Heparin Therapy

                                                    4 Hours if not on Heparin Therapy

 

Day(s) Performed

Daily

Available STAT

Analytical Time: 1 Day

 

Aliases

PTT (Partial Thromboplastin Time)

Partial Thromboplastin Time

PTT

 

Test Classification and CPT Coding

85730