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Test Code
PTT
Test Name
Activated Partial Thromboplastin Time
CPT Codes
85730
Expected Turnaround Time
1 day
Clinical Utility
Used in the evaluation of the intrinsic coagulation system, coagulation disorders and deficiencies.
Specimen and Container Info

Specimen Type: Plasma

Collection Container: 1 Full Light Blue Top (Sodium Citrate)  
Collection Instructions
Blood should be collected in a blue-top tube containing 3.2% buffered sodium citrate. Evacuated collection tubes must be filled to completion to ensure a proper blood-to-anticoagulant ratio.
Processing and Submission Instructions

If testing cannot be completed within 24 hours for non-heparinized or 4 hours for heparinized, create platelet poor plasma according to Specimen Collection and Processing Guidelines for Coagulation Testing.

Transport Instructions

 Transport to the laboratory at room temperature.
Stability Requirements

Room Temperature

  • Non-heparinized patient: 24 hours
  • Heparinized or inpatient: 4 hours

Frozen

Platelet poor plasma: 14 days
Causes for Rejection
  • Clotted specimen
  • Specimen past stability
  • Specimen not properly filled
Methodology
Mechanical Clot Detection
Reference Intervals

Age

PTT (seconds)

0 - 2 days

34.3 - 44.8

3 days - < 1 month

29.5 - 42.2

1 month - <1 year

35.1 - 46.3

1 year - <6 years

33.6 - 43.8

6 years - <11 years

31.8 - 43.7

11 years - <17 years

33.9 - 46.1

≥17 years

21.6 - 35.6
Critical Values

HNL Lab Medicine Critical Values
Performing Location
17th Street Hospital, Carbon Hospital, Cedar Crest Hospital, Cedar Crest Red Lab, Dickson City Hospital, Hazleton Hospital, Hecktown Oaks Hospital, Muhlenberg Hospital, Pocono Hospital, Redeemer Health, Roble Road Core Laboratory, Schuylkill Hospital
Alternate Names
  • APTT
Testing Schedule
Routine daily, STAT testing available
The American Medical Association (AMA) Current Procedural Terminology (CPT) codes published by HNL Lab Medicine are guidelines and are intended for informational purposes only. CPT coding is the exclusive responsibility of the billing entity. View the Terms.
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