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Test Code LAB90573 Heparin Coverage (APTT) Activated Partial Thromboplastin Time (APTT), Blood

Reporting Title

APTT

Methodology

Diagnostica Stago, Inc.

Used as a screening test for coagulation abnormalities including intrinsic coagulation factors, presence of nonspecific inhibitors, and for monitoring heparin therapy.

Performing Laboratory

OhioHealth Laboratory Services-RMH, GMC, DH, DMH, GMH, MGH, GMH, HMH GCMH Core Laboratories

Specimen Requirements

Specimen must arrive within 8 hours of draw.

 

Draw a full, light blue-top (citrate) tube; and send citrated whole blood. Invert several times to mix blood. Forward unprocessed whole blood promptly at ambient temperature only. Do not refrigerate.

Note:  Gross hemolysis, lipemia, and icteric specimen may affect results.

 

Plasma-Frozen

Draw a full, light blue-top (citrate) tube. Spin down, remove plasma, spin plasma again, and place 1 mL of citrated platelet-poor plasma into a plastic vial. (Glass vial is not acceptable.) Pour-off vial should be no more than 2/3 full. Send specimen frozen.

Specimen Stability Information

Specimen Type Temperature Time
Unspun whole blood Room Temperature 8 hours 
Spun, capped whole blood Room Temperature 8 hours 
  Refrigerate Do not refrigerate

 

Specimen Transport Temperature

Ambient OK /Refrigerate NO/Frozen OK

Reference Values

23-34 seconds

Therapeutic range:  68-104 seconds

Critical values: > 130 seconds

Alerting category: Always called within 1 hour

APTT results may be affected by a number of commonly administered drugs. Decreased APTT results can be seen with estrogen therapy in males or oral contraceptive use in females. Increased APTT results can be seen in diphenylhydantoin, heparin, warfarin, naloxone, and radiographic agent administration.

Unexpected abnormal APTT results should be followed up with additional coagulation studies to determine the cause of abnormal results.

Day(s) Test Set Up

Monday through Sunday; Continuously

Test Classification and CPT Coding

85730