Diagnostics and Laboratory Testing

Question 1

Diagnostic efficacy

Answer 1

does the test correctly identify abnormalities?

Question 2

Diagnostic effectiveness

Answer 2

does the test change your diagnosis?

Question 3

therapeutic efficacy

Answer 3

does the test change your management?

Question 4

therapeutic effectiveness

Answer 4

does the test change the patient’s outcome?

Question 5

sensitivity

Answer 5

true positive rate
how accurate is it to give the result I’m suspecting
want 90% sensitivity

Question 6

specificity

Answer 6

true negative rate
tells you the patient doesn’t have it/they have a negative result
want 90% specificity

Question 7

an asymptomatic patient with abnormal results

Answer 7

does not equal significant disease

Question 8

likelihood ratio

Answer 8

describes the proportion of accurate and inaccurate positive test results
LR = sensitivity / (1-specificity) or TP rate/ FP rate

Question 9

likelihood ratios greater than 10 provide ___

Answer 9

considerable confidence

Question 10

tests part of the CBC

Answer 10

RBC, red blood cell indices (MCV, MCH, MCHC, RBC distribution width), WBC, platelet count

Question 11

RBC normal values (males and females)

Answer 11

males: 4.7 -6.1 x 10^6 / uL
females: 4.2 - 5.4 x 10^6/uL

Question 12

Hemoglobin normal values (males and females) and critical values

Answer 12

males: 14 - 18 g/dL
females: 12 - 16 g/dL
critical values: <5 or >20

Question 13

Hematocrit normal values (males and females) and critical values

Answer 13

males: 42 - 52%
females: 37 - 47%
critical values: <15% or > 60%

Question 14

MCV normal value

Answer 14

80 - 90 fL

Question 15

MCH normal value

Answer 15

27 - 31 pg

Question 16

MCHC normale value

Answer 16

32 - 36 g/dL (32% - 36%)

Question 17

RBC distribution width normal value

Answer 17

11 - 14.5%

Question 18

WBC normal value and critical values

Answer 18

5 - 10 x 10^9/ L

critical: <2.5 or >30

Question 19

Neutrophils normal value

Answer 19

55-70%

Question 20

Lymphocytes normal value

Answer 20

20-40%

Question 21

Monocytes normal value

Answer 21

2-8%

Question 22

Eosinophils normal value

Answer 22

1-4%

Question 23

Basophils normal value

Answer 23

0.5 -1%

Question 24

Platelet count normal values and critical values

Answer 24

150 -400 x 10^9/L

critical: <40 or >1000

Question 25

thrombocytopenia numeric value

Answer 25

<100 x 10^9/L

Question 26

thrombocytosis numeric value

Answer 26

> 400 x 10^9/L

Question 27

thrombocythemia numberic value

Answer 27

> 1000 x 10^9 /L

Question 28

if less than _____ , hesitate to put in epidural/spinal in due to risk of _____

Answer 28

100,000

hematoma that could compress the cord

Question 29

when are coagulation studies indicated?

Answer 29

patients taking anticoagulants, liver disease, coagulation disorder, and malnutrition

Question 30

are coagulation studies predictive of perioperative bleeding?

Answer 30

no

Question 31

which clotting factor is not made in the liver?

Answer 31

Von Willebrand Factor

Question 32

what tests are considered coagulation tests?

Answer 32

activated clotting time, bleeding time, platelet count, PT, aPTT, INR, Ecarin clotting time

Question 33

PT normal value

Answer 33

12 - 14 seconds

Question 34

aPTT normal value

Answer 34

25 -32 seconds

Question 35

Which test evaluates EXTRINSIC factor function?

Answer 35

PT and INR

Question 36

Which test evaluates INTRINSIC factor function?

Answer 36

aPTT

Question 37

INR normal value

Answer 37

0.8 - 1.1

Question 38

Which coagulation study is the most accurate?

Answer 38

INR

Question 39

ACT normal value

Answer 39

80 -150 seconds

Question 40

Bleeding time normal value

Answer 40

3 - 7 minutes

Question 41

Which patients/disease processes should you consider getting serum chemistry?

Answer 41

hepatic or renal disease, malnutrition, malabsorption, ETOH abuse, gastric bypass, anasarca

Question 42

What tests are included in the serum chemistry?

Answer 42

sodium, potassium, carbon dioxide, calcium, chloride, glucose

Question 43

Na+ normal values

Answer 43

135 - 145 mEq/L

Question 44

K+ normal values

Answer 44

3.5 - 5.0 mEq/L

Question 45

CO2 normal values

Answer 45

23 - 29 mEq/L

Question 46

Ca++ normal values

Answer 46

8.5 - 10.5 mg/dL

Question 47

Cl- normal values

Answer 47

96 - 106 mmol/L

Question 48

Glucose normal values

Answer 48

fasting: 70 - 99 mg/dL

postprandial at 2 hours: <140 mg/dL

Question 49

What other patients/disease processes might you consider checking renal function tests on?

Answer 49

diabetics, hypertension, family history, elderly, taking diuretics, when radiographic dye will be used

Question 50

What tests are included in renal function tests?

Answer 50

BUN, creatinine, eGFR

Question 51

BUN normal values

Answer 51

5 - 25 mg/dL

Question 52

creatinine normal values

Answer 52

0.6 - 1.2 mg/dL

Question 53

which test is the most accurate reflection of renal function?

Answer 53

creatinine clearance

it is a reflection of GFR

Question 54

pregnancy testing may be valuable in ____

Answer 54

pediatric patients having menses, poor historians, irregular periods, undergoing infertility treatment

Question 55

what is the most frequently ordered preoperative test?

Answer 55

ekg

Question 56

MET desirable score

Answer 56

> 4 (ability to climb two flights of stairs)

key to determining need for preop cardiac testing