aPTT

Alphabetical Test listing

aPTT-490

  
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.

  
Sodium citrate (Na cit) plasma
  

Lt blue Sodium citrate (NaCit)

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 guideline

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

  

Routine requests: 

  1. Process Platelet Poor Plasma (P.P.P) following the linked instructions.

  2. Separate plasma into two (2) 1 mL aliquots and apply spot label "NaCit Plasma P.P.P"
  3. Freeze immediately

STAT requests only:

Send whole blood sample in original collection container with STAT courier.

Must be tested within 4 hours of collection.

  

Routine:

Two (2) Microcentrifuge vial/tubes in a Snap cap conical vial/tube and cap (Beaker sites)

                             

 

Two (2) Coagulation specimen transport vial/tube  (all other sites)

                                     

STAT:

Lt blue top (3.2% Na Citrate) tube

  

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
  
AHL - Coagulation: W
  
Daily
Available STAT
  
1 day
  

Coagulation test method

  

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

  
85730
  
Yes
  
  
11/30/2001
  
09/10/2021
  
06/30/2020