Clinical Lab Data Flashcards

1
Q

define accuracy

A

agreement between measured quantity and true value

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

define precision

A

agreement between repetitive measures

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

_________ is a test of reproducibility

A

precision

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

3 measures of precision

A

arithmetic mean
standard deviation
coefficient of variation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

explain what coefficient of variation is

A

expresses standard deviation as a percentage of the mean

standard deviation/sample mean

measure of PRECISION

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

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

A

95% confidence intervals, plus minus 2 standard deviations

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

what are the 2 most important factors for reference intervals

A

gender and age

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

can a healthy person have an abnormal lab test value?

A

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

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

true or false

abnormal results are a consequence of multiple testing

A

true

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

sensitivity refers to…..

A

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

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

a sensitivity of 95% means…….

A

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

5% with the disease will have false negative results

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

what is specificity?

A

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

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

a specificity of 95% means….

A

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

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

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

prevalence is defined as….

A

the % of the general population who have the disease

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

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

what is a screening test

A

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

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

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

A

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

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

CBC vs CBC with differential

A

CBC with differential includes types of WBC

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

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

A

lymphocytes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

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

A

granulocytes (neutrophils, bands)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

the normal ratio of CD4:CD8 is….

A

2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

what measures ALL phases of coagulation?

A

bleeding time

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

what measures the extrinsic clotting pathway?

A

prothrombin time (PT)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

what measures the intrinsic clotting pathway?

A

partial thromboplastin time (PTT)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

_______ is increased by administration of coumadin

A

prothrombin time (PT)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

________ is increased by administration of heparin

A

partial thromboplastin time (PTT)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

when would chloride levels be elevated

A

in dehydration

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

when would sodium levels be elevated?

A

dehydration
hyperaldosteronism

28
Q

when would sodium levels be decreased?

A

by sweating

29
Q

abnormal levels of potassium are associated with…..

A

myocardial infarction

30
Q

potassium levels may be elevated in what 2 scenarios?

A

adrenal insufficiency
renal failure

31
Q

potassium levels may be depressed due to what 3 scenarios

A

malabsorption
starvation
diuretics

32
Q

carbon dioxide levels are elevated when?

A

in emphysema

33
Q

when are carbon dioxide levels depressed?

A

starvation
diarrhea
diabetic acidosis

34
Q

when is BUN (blood urea nitrogen) elevated?

A

in impaired renal function

35
Q

when is BUN (blood urea nitrogen) depressed?

A

in liver damage

36
Q

when would creatinine levels be elevated

A

in impaired renal function

37
Q

when are glucose levels elevated

A

diabetes mellitus

38
Q

in what 3 scenarios would glucose levels be depressed

A

pancreatic disorders
endocrine disease
liver disease

39
Q

low levels of _______ are an acute medical emergency

A

glucose

40
Q

true or false

high levels of glucose are an acute medical emergency

A

FALSE

low levels

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

41
Q

elevations in liver enzymes are associated with….

A

liver damages like hepatitis and cirrhosis

42
Q

name 4 liver enzymes

A

lactate dehydrogenase

alkaline phosphatase

aspartate aminotransferase

alanine aminotransferase

43
Q

urinalysis may be useful to assess……

A

renal function

44
Q

what ph should the urine be

A

4.5-8.5

45
Q

true or false

the urine should not have any cells in it

A

true

46
Q

____ and ____ should be negative in the urine

A

glucose
microalbumin

47
Q

what are therapeutic drug levels?

A

measures the blood levels of ingested meds

elevated levels may be toxic

48
Q

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

A

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

49
Q

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

A

occurs in smallest arteries, arterioles, and capillaries

includes diabetic neuropathy, nephropathy, cardiac dysfunction, diabetic retinopathy

50
Q

how is diabetes mellitus diagnosed

A

symptoms
examination of random or of fasting blood glucose

51
Q

blood glucose testing is performed mainly on…..

A

venous plasma

52
Q

explain how glycemic control is monitored

A

daily self monitoring of blood glucose conc

bi-monthly - quarterly: HbA1c

53
Q

explain what HbA1c is a measure of

A

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

54
Q

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

A

normally less than 6%

in diabetic patients it can increase 2-3 times

55
Q

how is HbA1c formed?

A

by the non-enzymatic attachment of glucose to haemoglobin

slowly and continuously formed

56
Q

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

A

diabetic nephropathy

may progress to end-stage renal failure

57
Q

how is microalbumin detected?

A

by sensitive immuno assays

58
Q

why is testing microalbumin important for diabetic patients?

A

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

59
Q

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

A

sodium
potassium
chloride

60
Q

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

A

coagulation studies

61
Q

in liver disease, what 2 things are examined

A

liver enzymes
coagulation studies

62
Q

in renal disease what 2 things are examined

A

electrolytes
urinalysis

63
Q

in respiratory disease what is examined

A

electrolytes

64
Q

what are test kits used for?

A

used to identify bacteria within 24-48 hourd

65
Q

explain how bacterial test kits work

A

microtubes contain dehydrated substances inoculated with suspension

they are incubated and any color change means enzymatic activity or carbohydrate fermentation

66
Q

as sensitivity increases, what happens to specificity?

A

it decreases

67
Q
A