aPTT-490

Test info

  
aPTT
  
490
  
85730.0
  
PTT
  
Activated partial thromboplastin time
aPTT
  

The activated partial thromboplastin time (aPTT) test is a screening procedure used primarily to determine deficiencies in factors necessary for the formation of intrinsic prothrombin activator, namely factors VIII, IX, XI and XII.

Factors II, V and X deficiencies (normally detected by the prothrombin time) can also be detected by the aPTT.

The test will not detect platelet disorders, isolated factor XII and factor XIII deficiencies.

Specimen

  
Sodium citrate (Na cit) plasma
  

Lt blue Sodium citrate (NaCit) - 2.7mL

If the patient has a hematocrit >55, a specially prepared Lt blue Sodium citrate (NaCit) tube must be used in place of the standard Lt blue Sodium citrate (NaCit) tube.

Hematocrit-Anticoagulant adjustments

  
1.5 mL
  
0.6 mL
  
  • Do not over or under fill tube as the ratio of anticoagulant to whole blood is critical

Coag – tube fill guidelines

  • Mix by gentle inversion 3 - 4 times
  
  
  
Sodium citrate (Na cit) whole blood - STAT requests only
  
2.7 mL
  

Lt blue Sodium citrate (NaCit) - 2.7mL

  

Routine:

Frozen (strict)

Refrigerated - NO

STAT:

Ambient

  • Patient not on heparin: 4 hours
  • Patient on heparin: specimen must be processed within 1 hour of collection, and testing run within 2 hours of collection.
  
  • Improper label (unlabeled or mislabeled)
  • Improper anticoagulant
  • Improperly filled tube
  • Hemolysis
  • Clotted specimen
  • Delay in transport
  • Improper storage/transport temperature
  • Patient on heparin > 1.0 IU/mL

Performance

  
AHL - Coagulation: W
  
Daily
Available STAT
  
1 day
  

Coagulation test method

Clinical and Interpretive info

  

0-2 months:  29 - 50 seconds

3-6 months:  28 - 43 seconds

Adult:            25 - 36 seconds

Heparin therapeutic range: 76 - 99 seconds

  

0 - 28 days of age or outpatient: > 60 seconds

Billing

  
85730
  
Yes
  

Tracking

  
11/30/2001
  
09/10/2021
  
06/30/2020