12 Diagnostics and troubleshooting
PFA-100 System – Instruction Manual (US) – Version 1.0.1
912
12.5.4 Test Terminated Due To Insufficient Sample
The following table contains information about the circumstances in which the message TEST TERMINATED DUE
TO INSUFFICIENT SAMPLE occurs and how to proceed afterwards.
Description Causes Solutions/Comments Result Interpretation
The analyzer has detected air
being drawn subsequent to the
first 30seconds of testing. This
condition is detected whenever
the test runs out of sample and
closure of the aperture has not
occurred.
• Not enough sample was
loaded in the PFA test
cartridge.
• Sufficient sample was loaded
in the PFA test cartridge but
closure of the aperture did not
occur due to platelet
dysfunction and/or low
sample viscosity
(
hematocrit, high
sedimentation rate).
• Verify that 800 µL was added to the PFA test
cartridge. Rerun sample using 900 µL.
• Verify sample hematocrit is within normal
range. Refer to the instructions for use
(Limitations of Procedure section) for further
information. An abnormal hematocrit may
impair platelet function and result in
prolongation of the closure time. Platelet
dysfunction in combination with low
hematocrit will often induce this type of
status message. Samples from patients
treated with platelet antagonist drugs may
exhibit characteristics that cause this type of
status message. Adding additional
specimen (up to 900 µL) could eliminate the
insufficient sample message but a
combination of low hematocrit and platelet
dysfunction will most likely result in a
closure time > 300 sec.
• The PFA test cartridge cup serves as the
receptacle where blood is collected after it
passes through the membrane aperture.
During a test, the analyzer vacuum chuck
interfaces with the cup and comes in close
proximity to blood. Air that is drawn into the
cup whenever an insufficient sample occurs
can cause blood to foam and contaminate
either the vacuum chuck or O-Ring. It is
recommended to perform manual cleaning
of the O-Ring with the cleaning pad to avoid
potential contamination.
An insufficient sample message
that occurs at a time that is
greater than the upper limit of the
reference range may indicate
abnormal platelet function due to
the reasons stated above. In
such cases this result may be
reported as the time in which the
test ended, >xxxsec, with a
statement qualifying the
properties of the sample (i.e.
abnormal hematocrit and/or low
platelet count) and suspicion of
platelet dysfunction.
Table 12-4 Test Terminated Due To Insufficient Sample
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