Unit 1 - Redone Flashcards
Material with known value of analyte and unknowns compared to it
Calibrator
This has traceability
What is traceability?
Calibrators
Able to trace back a secondary and working standard back to the primary calibrator used
What do we assume about calibrators?
That they’re perfect
Material with known value of analyte and unknowns not compared to it
Controls
This material tests if a test system is working properly
Control
This should have commutability; what is that?
Controls
Controls aren’t made from organic material like specimens, but has to be close enough
T/F: Controls identify problems with individual specimens?
False
What percentage of healthy people fall outside of the Gaussian distribution?
5%
There is _____ that diseased people will fall outside the reference interval
no guarantee
What is required when reporting critical values?
1) Verbal communication
2) Read back
3) Documentation
Critical action value vs Critical decision limit
CAV - something needs to be done now
CDL - value results in treatment
This urine specimen avoids short-term variations
Timed
This urine specimen is to detect UTI/bacterial infections
Midstream
This urine specimen is usually the most concentrated
Learn, early morning, fasting
This specimen requires no preservatives
Fecal
fasting
no food or drinks, only water 8-12 hours before
post prandial
after a meal
First
Second
Third choices for specimen from an IV
1st: arm w/o IV
2nd: more than 4 inches below iV
3rd: turn off at least 2 minutes, draw above IV
blood volume changes when patient goes from lying down to standing up
BV decreases by 9% for up to 30 minutes
What does premature separation do to blood
continued clotting after separation
Evaporation can cause analytes to be falsely __
increased
Evaporation can cause volatile analyses to be falsely ___
decreased
Hemolysis absorbance peak
415 nm
Icterous/bilirubin absorbance peak
454 nm
Lipemia absorbance peak
700 nm
Persistent hemolysis can indicate what?
Intravascular hemolysis
3 strategies for handling HIL interferences
Report
Cancel
Dilute
If you report an HIL result; what needs to go in the report?
Comment about the interference
IF okay for analyte
If you dilute an HIL specimen; what needs to happen?
Get analyte value and report after multiplying by dilution factor
Order of draw
Stop - Sterile
Light - Light blue
Red - Red
Stay - SST
Put - PST (light green)
Green - Green
Light - Lavender
Go - Gray
Pre-Analytical
Specimen collection, labeling, processing, storage
Analytical
Verify labeling is correct
Visualize acceptability
Quality Control!
Quality Assurance!
Quality Control
Detect errors before specimen is reported
Quality assurance
Error prevention
Insensitivity of a method causes…
False decrease
Oversensitivity of a method causes…
False increase
Hemoconcentration
Loss of fluid
False elevation
Hemodilution
Increase of fluid
False decrease
Hct values in newborns
High
Dead volume
More specimen than actually pipetted
Problems with capillary specimens
More hemolysis
Tissue fluid contamination
Difficult blood flow
Why are evacuated tubes not ideal for pediatric specimens?
Small veins, can collapse
Why don’t you want to use cotton balls for urine collection?
Fibers can interfere with urine microscopics
