Case Study
A young patient is admitted from the emergency room with petechial bruising. The attending physician orders a battery of tests including a PT and aPTT. The laboratory performs the requested testing and the result of the aPTT is normal; however the PT is prolonged:
PT: 38 seconds (normal range 11-13 seconds)
aPTT: 32 seconds (normal range 21-34 seconds)
The physician then decides to order a mixing study for further analysis since the patient is not taking any oral anticoagulants, nor does she meet the known patient histories associated with prolonged PT results.
