aPTT
– 2
Lupus anticoagulant:
Factor deficiencies (<0.3 U/mL or
<100 mg/dL (I)
Heparin therapy ongoing
Same as those for PT
Average time of duplicate runs
reported in seconds
Prolonged aPTT seen in:
Quality
Control:
Reporting of
results:
Results of normal control also
reported with patient results
Therapeutic
range for unfractionated heparin:
Collect 50 or more specimens from
patients on heparin only
Perform aPTT on each specimen in
duplicate
Perform chromogenic anti-Xa heparin
assay on each