Clinical Lab Data

Question 1

define accuracy

Answer 1

agreement between measured quantity and true value

Question 2

define precision

Answer 2

agreement between repetitive measures

Question 3

_________ is a test of reproducibility

Answer 3

precision

Question 4

3 measures of precision

Answer 4

arithmetic mean
standard deviation
coefficient of variation

Question 5

explain what coefficient of variation is

Answer 5

expresses standard deviation as a percentage of the mean

standard deviation/sample mean

measure of PRECISION

Question 6

What confidence intervals are used to determine whether 2 tests can be used, solely based on how precise they are?

Answer 6

95% confidence intervals, plus minus 2 standard deviations

Question 7

what are the 2 most important factors for reference intervals

Answer 7

gender and age

Question 8

can a healthy person have an abnormal lab test value?

Answer 8

yes, bc reference intervals are designed to include 95% of the values from a healthy reference population, there is a 5% chance

Question 9

true or false

abnormal results are a consequence of multiple testing

Answer 9

true

Question 10

sensitivity refers to…..

Answer 10

the% of positive test results in patients with a particular disease

Question 11

a sensitivity of 95% means…….

Answer 11

95% of patients with the disease will be affected by the test

5% with the disease will have false negative results

Question 12

what is specificity?

Answer 12

refers to the % of negative test results in patients WITHOUT a particular disease

Question 13

a specificity of 95% means….

Answer 13

95% of patients WITHOUT the disease will have a negative result

5% of patients WITHOUT the disease will have a false positive result

Question 14

prevalence is defined as….

Answer 14

the % of the general population who have the disease

expressed as # of people with the disease per 100,000 people

Question 15

what is a screening test

Answer 15

a test used to screen a population of people for the presence of a particular disease

Question 16

screening tests that are performed on unselected populations in which disease prevalence is very low will yield……

Answer 16

overwhelmingly false positives even if the test has a very high specificity

Question 17

CBC vs CBC with differential

Answer 17

CBC with differential includes types of WBC

Question 18

in a CBC with differential, presence of _____ is an indicator of immune system status

Answer 18

lymphocytes

Question 19

in a CBC with differential, _____ is an indicator of the ability to manage infection

Answer 19

granulocytes (neutrophils, bands)

Question 20

the normal ratio of CD4:CD8 is….

Answer 20

2

Question 21

what measures ALL phases of coagulation?

Answer 21

bleeding time

Question 22

what measures the extrinsic clotting pathway?

Answer 22

prothrombin time (PT)

Question 23

what measures the intrinsic clotting pathway?

Answer 23

partial thromboplastin time (PTT)

Question 24

_______ is increased by administration of coumadin

Answer 24

prothrombin time (PT)

Question 25

________ is increased by administration of heparin

Answer 25

partial thromboplastin time (PTT)

Question 26

when would chloride levels be elevated

Answer 26

in dehydration

Question 27

when would sodium levels be elevated?

Answer 27

dehydration hyperaldosteronism

Question 28

when would sodium levels be decreased?

Answer 28

by sweating

Question 29

abnormal levels of potassium are associated with.....

Answer 29

myocardial infarction

Question 30

potassium levels may be elevated in what 2 scenarios?

Answer 30

adrenal insufficiency renal failure

Question 31

potassium levels may be depressed due to what 3 scenarios

Answer 31

malabsorption starvation diuretics

Question 32

carbon dioxide levels are elevated when?

Answer 32

in emphysema

Question 33

when are carbon dioxide levels depressed?

Answer 33

starvation diarrhea diabetic acidosis

Question 34

when is BUN (blood urea nitrogen) elevated?

Answer 34

in impaired renal function

Question 35

when is BUN (blood urea nitrogen) depressed?

Answer 35

in liver damage

Question 36

when would creatinine levels be elevated

Answer 36

in impaired renal function

Question 37

when are glucose levels elevated

Answer 37

diabetes mellitus

Question 38

in what 3 scenarios would glucose levels be depressed

Answer 38

pancreatic disorders endocrine disease liver disease

Question 39

low levels of _______ are an acute medical emergency

Answer 39

glucose

Question 40

true or false high levels of glucose are an acute medical emergency

Answer 40

FALSE low levels high values may be better tolerated dep on usual levels of the pt

Question 41

elevations in liver enzymes are associated with....

Answer 41

liver damages like hepatitis and cirrhosis

Question 42

name 4 liver enzymes

Answer 42

lactate dehydrogenase alkaline phosphatase aspartate aminotransferase alanine aminotransferase

Question 43

urinalysis may be useful to assess......

Answer 43

renal function

Question 44

what ph should the urine be

Answer 44

4.5-8.5

Question 45

true or false the urine should not have any cells in it

Answer 45

true

Question 46

____ and ____ should be negative in the urine

Answer 46

glucose microalbumin

Question 47

what are therapeutic drug levels?

Answer 47

measures the blood levels of ingested meds elevated levels may be toxic

Question 48

what accounts for most of the excess mortality associated with diabetes?

Answer 48

macrovascular disease - complications related to accelerated atherosclerosis in large-medium arteries

Question 49

microvascular disease is also a long term complication of diabetes. what is it?,

Answer 49

occurs in smallest arteries, arterioles, and capillaries includes diabetic neuropathy, nephropathy, cardiac dysfunction, diabetic retinopathy

Question 50

how is diabetes mellitus diagnosed

Answer 50

symptoms examination of random or of fasting blood glucose

Question 51

blood glucose testing is performed mainly on.....

Answer 51

venous plasma

Question 52

explain how glycemic control is monitored

Answer 52

daily self monitoring of blood glucose conc bi-monthly - quarterly: HbA1c

Question 53

explain what HbA1c is a measure of

Answer 53

provides an index to the "average" plasma glucose over the preceding 2-3 months

Question 54

what is the normal HbA1c level? what is it in diabetic patients?

Answer 54

normally less than 6% in diabetic patients it can increase 2-3 times

Question 55

how is HbA1c formed?

Answer 55

by the non-enzymatic attachment of glucose to haemoglobin slowly and continuously formed

Question 56

_______ is a major complication if insulin dependent diabetics. it may progress to.....

Answer 56

diabetic nephropathy may progress to end-stage renal failure

Question 57

how is microalbumin detected?

Answer 57

by sensitive immuno assays

Question 58

why is testing microalbumin important for diabetic patients?

Answer 58

if detected early, it can allow the reversal of nephropathy bc once proteinurea happens, treatment may slow progression of kidney disease but CANNOT be reversed at this point

Question 59

what are the most commonly disturbed electrolytes in congestive heart failrure?

Answer 59

sodium potassium chloride

Question 60

CVA (stroke) and valvular heart disease - what test is performed

Answer 60

coagulation studies

Question 61

in liver disease, what 2 things are examined

Answer 61

liver enzymes coagulation studies

Question 62

in renal disease what 2 things are examined

Answer 62

electrolytes urinalysis

Question 63

in respiratory disease what is examined

Answer 63

electrolytes

Question 64

what are test kits used for?

Answer 64

used to identify bacteria within 24-48 hourd

Question 65

explain how bacterial test kits work

Answer 65

microtubes contain dehydrated substances inoculated with suspension they are incubated and any color change means enzymatic activity or carbohydrate fermentation

Question 66

as sensitivity increases, what happens to specificity?

Answer 66

it decreases