08a: Lab Medicine

Question 1

List the various sections of clinical labs (at BMC).

Answer 1

1. Chem
2. Hematology
3. Microbio
4. Blood bank

Question 2

Organ (renal, cardiac, liver, etc.) function tests are processed by which clinical lab?

Answer 2

Chemistry

Question 3

Blood count and urinalysis are tests processed by which clinical lab?

Answer 3

Hematology

Question 4

Coagulation and flow cytometry tests processed by which clinical lab?

Answer 4

Hematology

Question 5

Culture, stains, and chemical reactions to ID microorganisms are tests processed by which clinical lab?

Answer 5

Microbiology

Question 6

Tests for toxicology and to ID tumor markers are processed by which clinical lab?

Answer 6

Chemistry

Question 7

Clinical labs: blood bank primary responsibility…

Answer 7

Provide blood products for transfusion (and perform tests to ensure transfusion is safe)

Question 8

(X) tests are performed by clinicians at patient bedside, not in a lab by technologist. Give some examples of these.

Answer 8

X = point of care

Fingerstick glucose, Guaiac, urine pregnancy test

Question 9

Which factors are important to consider in pre-analytic phase of clinical testing?

Answer 9

1. Proper pt ID and specimen labeling
2. Time of day specimen collected
3. Proper tube for test

Question 10

Most lab tests are (quantitative/qualitative) and interpreted by (technician/pathologist) (with/without) review by (technician/pathologist).

Answer 10

Quantitative;
Technician
Without pathologist review

Question 11

At the analytic phase of clinical tests, the role of pathologist is to interpret:

Answer 11

Qualitative/interpretational tests (i.e. problematic smears)

Question 12

Interference can be a problem in (pre-analytic/analytic/post-analytic) phase of lab testing. Give some examples of this.

Answer 12

Analytic;

1. Hemolysis or lipemia (if test depends on optical transmittance)
2. Pt with anti-animal Ab (false positive immunoassays)

Question 13

“Critical alert value” (CAV) lab tests must be relayed from (X) to (Y) within (Z) minutes/hours of lab result.

Answer 13

X = lab
Y = ordering clinician
Z = 30 min

Question 14

Lab medicine: Turnaround time is time it takes from (X) to (Y). List some tests that require fast TAT.

Answer 14

X = specimen draw/receipt into lab
Y = generation of lab result

Blood gas

Question 15

T/F: QC (quality control) optimizes the post-analytic phase of lab testing.

Answer 15

False - analytic phase

Question 16

For most lab tests, how often is QC run?

Answer 16

3 times a day (beginning of each shift)

Question 17

(X) is the systematic approach overseen by pathologist/medical director and lab supervisor to improve (pre-analytic/analytic/post-analytic) phase of lab function.

Answer 17

X = quality assurance (QA)

All three (overall lab function)

Question 18

Lab medicine: how is a new instrument “validated”?

Answer 18

Compare with either previous instrument or gold standard

Question 19

Lab medicine: reference range created for every test using (X). How wide is this range?

Answer 19

X = patient’s demographics

Values within 2 SDs of mean (95% of normal/non-diseased individuals)

Question 20

Sensitivity equation:

Answer 20

TP/(TP+FN)

Question 21

Sensitivity is a measure of how good a(n) (normal/abnormal) test result detects (normal/disease) process.

Answer 21

Abnormal; disease

Question 22

Specificity equation:

Answer 22

TN/(TN+FP)

Question 23

Specificity is a measure of how good a(n) (normal/abnormal) test result detects (normal/disease) process.

Answer 23

Normal; normal

Question 24

PPV equation:

Answer 24

TP/(TP+FP)

Question 25

PPV is probability that:

Answer 25

Positive test predicts patient has disease

Question 26

NPV equation:

Answer 26

TN/(TN+FN)

Question 27

NPV is probability that:

Answer 27

Negative test predicts absence of disease

Question 28

Screening tests should have good (sensitivity/specificity). And confirmatory tests?

Answer 28

Sensitivity;

specificity