M103 T3 L8

Question 1

What percentage of clinical decisions are informed by data from Laboratory Medicine?

Answer 1

70%

Question 2

Why are lab tests requested?

Answer 2

when screening for disease
when looking for risk stratification
when diagnosing a disease
when looking for a prognosis
when monitoring the progression / remission of disease
when monitoring therapy
therapeutic drug monitoring
when looking for side effects of treatment

Question 3

What is the focus of Therapeutic drug monitoring?

Answer 3

to analyse the measurements of medication levels in blood

Question 4

What are the four main divisions of pathology?

Answer 4

Histology and Cytology
Bacteriology and Virology
Haematology
Biochemistry and Immunology

Question 5

What types of tissue diagnosis can be found when analysing Histology and Cytology? (MIA)

Answer 5

malignancy, infection, auto-immune

Question 6

What causes of infection can be found when analysing Bacteriology and Virology?

Answer 6

culture, antigen and antibody testing
increasingly PCR
Antibiotic use, public health, environmental testing

Question 7

What haematologies can be found when analysing blood pathology?

Answer 7

Diseases of the blood
Transfusion
Coagulation

Question 8

What substances can analytes be measured from when analysing bBiochemistry and Immunology?

Answer 8

blood, urine, CSF

Question 9

What substances are analysed in Clinical Chemistry?

Answer 9

Serum, CSF
Whole blood
Urine, Faeces, Sweat
Renal stones
Post-mortem samples
Miscellaneous fluids

Question 10

What substances are tested for in clincial chemistry?

Answer 10

Ions, Metabolites 
Waste products, Drugs
Markers of cell damage 
Functional enzymes, ATBYs
Vitamins, Metals
Plasma proteins
Antibodies, Hormones

Question 11

What are examples of metabolites that are tested for in clincial chemistry? (GALA)

Answer 11

glucose, amacs, lactate, lipids

Question 12

What are examples of waste products that are tested for in clincial chemistry? (CUBU)

Answer 12

creatinine, urea, bilirubin, uric acid

Question 13

What are examples of plasma proteins that are tested for in clincial chemistry?

Answer 13

lbumin, immunoglobulins, binding globulins, specific proteins

Question 14

What types of drugs are tested for in clincial chemistry?

Answer 14

therapeutic monitoring, toxicology

Question 15

What types of metals are tested for in clincial chemistry?

Answer 15

trace metals, toxins

Question 16

What substances are tested for when testing renal function?

Answer 16

Na+, K+

urea, creatinine

Question 17

What substances are tested for when testing liver function? (TAB.APAT)

Answer 17

total protein, albumin, bilirubin

alkaline phosphatase, alanine transaminase

Question 18

What substances are tested for when testing bone profile? (TAC.APP)

Answer 18

total protein, albumin, calcium, alkaline phosphatase, phosphate

Question 19

What substances are tested for when testing thyroid function?

Answer 19

TSH (free T4, free T3)

Question 20

What substances are tested for when testing lipid profile?

Answer 20

total cholesterol, HDL-cholesterol, non-HDL

cholesterol, triglycerides

Question 21

How are reference ranges generated?

Answer 21

take a large number of healthy individuals
measure the substance of interest
calculate the mean and standard deviation of the results
the reference range is [ “the mean - 2sd” - “the mean + 2sd” ]

Question 22

What percentage of population results are within the reference range?

Answer 22

95% of results (for the population)

Question 23

What percentage of population results are lower and higher than the reference range?

Answer 23

2.5% of results (for the population) for both lower and higher than the reference range

Question 24

Do results outside the reference range imply disease?

Answer 24

not necessarily – they may be a chance finding in a healthy individual.
the more extreme the value the more likely that an abnormality / disease is present

Question 25

Do results inside the reference range imply disease?

Answer 25

they don’t necessarily exclude disease

Question 26

What are two examples of substances that vary between genders?

Answer 26

testosterone

creatinine

Question 27

What is the purpose of measuring Creatinine levels?

Answer 27

to see how well the kidneys are functioning

Question 28

What do Creatinine levels vary with?

Answer 28

age and sex

Question 29

Why does creatinine vary with gender?

Answer 29

bc creatinine is produced by muscle and generally men have more muscle than women

Question 30

Why does creatinine vary with age?

Answer 30

bc muscle mass increases with age

Question 31

Why is it important not to just look at flagged results (outside the reference ranges)?

Answer 31

bc results can be outside the reference range in the absence of disease
results can be within the reference range when disease is present

Question 32

If it’s important not to just look at flagged results, how should results be used?

Answer 32

by finding patterns in the results to associate with specific conditions
by comparing current and previous results for significant differences in specific levels

Question 33

When are blood samples for an initial screen best collected at?

Answer 33

9am

Question 34

Why is the drug dexamethasone?

Answer 34

to suppress cortisol

Question 35

In what two conditions can alkaline phosphatase levels be elevated in?

Answer 35

in both liver disease and bone disease

Question 36

When are gGT levels measured?

Answer 36

when alkaline phosphatase levels are elevated and the diagnosis needs to be differentiated between either liver disease or bone disease

Question 37

When do elevated gGT levels indicate?

Answer 37

liver disease

Question 38

What does a change in creatinine of >26 umol/L indicate?

Answer 38

that acute kidney injury may be a possibility