|
Test Name
|
APTT-Sec
|
|
Test
Code
|
155
|
|
Specimen
|
Plasma
|
|
Unit
|
Seconds
|
|
Station
|
Coagulation
|
|
Synonym
Name/Abbreviation
|
Activated
Partial Thromboplastin Time; APTT
|
|
CPT
Code
|
85610
|
|
Performing
Facility
|
American
Medical Labs, Herzliya Pituah
|
|
Analyzer
|
Siemens,
Sysmex CA1500
|
|
Test
Method
|
Photo-optical
|
|
AML
Preferred Tube
|
Blue
top Na-Cit 3.2%
|
|
Collection/Storage
Instructions
|
Collection
tubes must be filled to completion to ensure a proper blood to anticoagulant ratio. The sample should be mixed immediately by gentle inversion at least six times to ensure adequate mixing of the anticoagulant with the blood.
When noncitrate tubes are collected for
other tests, collect sterile and nonadditive (red top) tubes prior to citrate (blue top) tubes.
Any tube containing an alternate anticoagulant
should be collected after the blue-top one. Gel-barrier tubes and serum tubes with clot initiators should also be collected after the citrate tubes.
Centrifuge and carefully remove the plasma using a plastic transfer pipette.
Transfer the plasma into a transport tube and send refrigerated to laboratory. Stability: up to 4h at 18 to 24 oC; frozen 2 weeks at -20oC;
-70oC up to 6 months.
|
|
Min.
Volume
|
1 mL plasma
|
|
Turn-Around-Time
|
One day
|
|
Intended
Use
|
Evaluation
of intrinsic coagulation system and monitoring heparin therapy; aid in detecting
classical Hemophilia A, Christmas disease, detection of congenital
deficiencies of factors II, V, VIII, IX, X, XI and
XII.
|
|
Limitations
|
Do not draw blood from an arm with a heparin lock or heparinized catheter; If
testing is ONLY for PT & PTT, draw “dead space” into an empty tube
first and discard before collection into NA-Cit tube. Result is sensitive
to plasma:citrate anticoagulant ratio, meaning if enough blood is not
added to the liquid citrate-containing tube when the specimen is drawn, an
erroneous PT result may be yielded. please Note that the PTT reagent test is not suitable for Lupus Amticoagulant (LAC).
|
|
Patient
Preparation
|
Draw
specimen 1 hour before next
dose of heparin if heparin is being given by intermittent injection.
Note: Requirements for patients receiving heparin are
different: If testing cannot be performed within one hour of
collection, frozen plasma must be submitted. Specimens should be
centrifuged for at least 10 minutes at 2500 rpm and the plasma quick
frozen and maintained in this condition until
tested.
|
|
Reasons
for Rejection
|
See:
requirements for patients; clotted specimen; frozen specimen thawed in
transit; tubes <90% full; improper labeling; specimen collected in tube
other than 3.2% citrate.
|
|
Adult
Reference Ranges
|
22.0
to 31.6
sec
|
