Clinical Blood Tests

Question 1

What makes up the “buffy coat” in a whole blood sample that has been centrifuged?

Answer 1

Leukocytes and Platelets

Question 2

What makes up plasma?

Answer 2

Whole blood without:
RBCs
WBCs
Platelets

Question 3

What makes up serum

Answer 3

Plasma without:
Fibrinogen
Clotting factors

Question 4

What is included in a basic electrolyte panel?

Answer 4

Na
K
Cl
HCO3-

Question 5

What is included in a basic metabolic profile?

Answer 5

Electrolyte panel
\+
glucose
BUN
Creatinine
(for kidney function)

Question 6

Main use for a comprehensive metabolic panel.

Answer 6

Liver function in addition to kidney function

Question 7

Normal BUN:Creatinine ratio

Answer 7

10-20:1

Question 8

What does an elevated BUN:Cr indicate?

Answer 8

Prerenal disease

Question 9

What does a decreased BUN:Cr indicate?

Answer 9

Postrenal disease or obstruction

Question 10

Major medication class that can skew a fasting glucose test

Answer 10

Steroids

Question 11

How is corrected calcium calculated?

Answer 11

0.8(normal albumin-measured albumin) + serum calcium

For every 1g albumin is low, calcium should be 0.8g low
Used when albumin levels are less than 4g/dL

Question 12

3 primary sources of alkaline phosphatase

Answer 12

Bone, liver, placenta

Question 13

What distinguishes which source of alkaline phosphatase causes a rise in the enzyme serum concentration?

Answer 13

Bone: usually in children
Liver: check Gamma-Glutamyl Transpeptidase (GGTP) levels, if they are elevated it’s the liver
Placenta: pregnant patients

Question 14

What can cause an elevation in unconjugated serum bilirubin?

Answer 14

Genetic disease in the neonatal period.

Question 15

What can cause an elevation in conjugated serum bilirubin?

Answer 15

Alcoholism

Gallstones

Question 16

When is an HbA1c test ordered?

Answer 16

To check for diabetes diagnosis in patients with borderline serum glucose levels.

To monitor patients already diagnosed with diabetes

Question 17

Enzyme measured that is very specific for cardiac injury.

Answer 17

Troponin I

Question 18

What can a Thyrotropin test be used for?

Answer 18

TSH test

• elevated TSH indicates hypothyroidism
• depressed TSH can indicate hyperthyroidism

Question 19

When is a free Thyroxine (T4) test used?

Answer 19

confirms a TSH test.
T4 is a product of the thyroid (it is thyroid hormone)
-if TSH is low and T4 is high = hyperthyroidism
-if TSH is high and T4 is low = hypothyroidism

Question 20

When are tumor marker tests most effective in regards to cancer diagnosis?

Answer 20

They are not used to diagnose cancer very often, they are mainly used to monitor already diagnosed cancers.

(Alpha-Fetoprotein and Prostate Specific antigen are more specific and may be used for diagnosis)

Question 21

What does a CBC with differential include that a standard CBC does not?

Answer 21

WBC count

Question 22

What do “Band neutrophils” often indicate?

Answer 22

They are immature neutrophils seen on blood smear. When in high levels, they often indicate rapidly producing WBCs in response to:

infection or
myeloproliferative disease

Question 23

What do the terms anisocytosis and poikilocytosis indicate?

Answer 23

Anisocytosis: RBCs varying in size
Poikilocytosis: RBCs varying in shape

Question 24

What does a low ferritin level indicate?

Answer 24

Not only is the patient iron deficient, they have been chronically iron deficient

Question 25

What measures Total Iron binding capacity?

Answer 25

Transferrin levels

Question 26

What does a reticulocyte count measure?

Answer 26

Erythropoetic activity of bone marrow

Question 27

What does a Partial Thromboplastin Time measure?

Answer 27

Clotting of the Intrinsic Pathway for Heparin monitoring

Question 28

Why is the International Normalized Ratio used?

Answer 28

Used for Warfarin monitoring

INR = Patient’s PT time/ Normal PT time

Question 29

What 3 things are elevated in urinalysis in patients with a UTI?

Answer 29

Leukocytes
Nitrite
Blood