L.05 Introduction Flashcards
What is Clinical Chemistry?
Clinical Chemistry involves the quantitative analysis of bodily fluids for diagnostic and therapeutic purposes
This field is essential for understanding patient health through laboratory tests.
What is an Error in the context of Clinical Chemistry?
The difference between the true value of a sample/analyte and the observed value obtained from the test performed
Errors can be associated with the test, analyser, or instrument used.
What are the two types of errors in Clinical Chemistry?
- Random error
- Systematic error
Random error involves fluctuations due to chance, while systematic error indicates a persistent bias.
Define Accuracy in Clinical Chemistry.
The closeness of a measured value to the true value
Accuracy is linked to systematic errors.
What term is used when a test is not accurate?
Inaccurate or biased
This indicates a failure in obtaining true values.
Define Precision in Clinical Chemistry.
The consistency or repeatability of measurements (closeness to each other)
Precision is linked to random error.
What term is used when a test is not precise?
Imprecise
This indicates variability in measurement results.
Why are trustworthy tests important in Clinical Chemistry?
- Correct diagnosis
- Reliability of treatment while monitoring a patient
Trustworthy tests ensure accurate disease management and treatment decisions.
Why is accurate glucose measurement critical?
It is critical for diagnosing diabetes and determining insulin dosage
Accurate measurements directly affect patient care.
What happens if measurements are imprecise?
Leads to uncertainty in management of disease
This could result in risks of over-treatment or under-treatment.
What does a Red blood collection tube signify?
No additive – test = immunology, drug, serology
Used for various blood tests without any additive interference.
What is the purpose of a Gold tube (SST)?
Clot activator with gel additive – test = all biochemistry tests
It separates serum from blood cells after clotting.
What does a Green tube contain?
Sodium or lithium heparin additive – test = special test, trace elements
Heparin prevents clotting for specific tests.
What is the additive in a Gray tube?
Sodium fluoride or potassium oxalate – test = blood sugar (plasma)
This additive preserves glucose levels for accurate testing.
Define Serum.
Liquid part of blood after clotting; fibrinogen + other clotting factors removed
It is used for various diagnostic tests.
Define Plasma.
Liquid part of blood when clotting is prevented (using anti-coagulant); contains all clotting factors including fibrinogen
Plasma is essential for tests that require the evaluation of clotting factors.
