Biochemical Testing Flashcards
Why is specimen testing performed?
To provide information for the appropriate treatment of patients
Results should be accurate, _________, and correctly interpreted
Relevant
List four scenarios for which testing is employed.
Diagnosis, prognosis, monitoring and treatment, and screening
What specimen is most commonly used for analysis?
Serum (plasma)
True or false: haemolysed samples are preferred for analysis.
False
If a patient is on an IV drip, a _________ site must be used for drawing blood.
Remote
List five controllable factors that may impact results.
Position of patient (impacts protein concentration), exercise (may increase creatinine kinase), time of day, lifestyle aspects, and diet
What factors affecting results are outwith the medical scientist’s control?
Age, gender, environment of patient, and existing medical conditions
______ tubes contain no anticoagulant or preservative, but may have a clot accelerator for serum samples.
Plain
Green heparin tubes are suitable for most analyses, with little interference, and they prevent the formation of ________ from fibrinogen.
Fibrin
Purple ethylenediaminetetraacetic acid (EDTA) tubes chelate _______, and are widely used.
Calcium
Grey ________ ____________tubes are used in blood glucose measurements; they also inhibit metabolic pathways, and used as a preservative with another anticoagulant, such as potassium oxalate.
Sodium fluoride
______ citrate tubes are used widely for coagulation studies, and can reversibly chelate calcium.
Blue
List three fields which must be included on a sample request form.
Patient name, DOB, and ward number
In specimen identification, ____________ is the technology of choice
Barcoding
For which analysis must the sample be protected from light?
Bilirubin
For all serum/plasma samples, separation should ideally be performed within ____ hours of the sample has being taken.
Two
List the four features than an ideal analysis method should have.
Accuracy, precision, sensitivity, and specificity
__________ indicates that a test will detect even very low levels of a particular analyte.
Sensitivity
What term defines a test’s ability to be unaffected by interference?
Specificity
Normality should be eschewed, in favour of patient results being described as being within, or outwith, the ___________ ________ (reference interval).
Reference range
Diagnostic methods may also be referred to as ________ methods.
Clinical
___________ _____________ measures the frequency of a test being positive, when a particular disease is present, a scenario known as a true positive (TP) result
Diagnostic sensitivity
___________ ____________ measures the frequency of a test being negative, when a particular disease is absent (a true negative (TN) result).
Diagnostic specificity
What is a predictive value?
A factor that plays a role in the ability of a test to diagnose disease is the prevalence of the condition in the population
Calculating the ________/________ predictive value gives the ability to accurately detect disease in a defined population.
Positive/negative
______ predictive value for a positive result (PPV) is very important, if the management or treatment of a patient with positive result would be dangerous to person with a false positive (FP).
High
What type of test should have a high predictive value for negative (NPV) results, and indicate that for all positive results, further investigation must be undertaken?
Screening
