L7 and L8 - Lab Medicine 1 and 2

Question 1

What is the purpose of lab testing?

Answer 1

Augments or supports information obtained from the history and physical
Confirms or rejects differential considerations (DDx)
Informs medical decision making
Allows for monitoring therapy

Question 2

What are the components of a CBC?

Answer 2

WBCs, hemoglobin, platelets, hematocrit

Question 3

What causes an increased WBC count?

Answer 3

Infections, inflammatory diseases, auto immune diseases, leukemia, emotional and physical stress

Question 4

What can cause the WBC count to be low?

Answer 4

Bone marrow failure (sepsis, malignancy)
Collagen vascular disease
Medications such as anti metabolites, barbiturates, anticonvulsants, anti thyroid

Question 5

When is hemoglobin increased?

Answer 5

Increased in severe dehydration, COPD, polycythemia, erythrocytosis, shock, CHF and high altitudes

Question 6

When is hemoglobin decreased?

Answer 6

In hemolytic reactions, acute or chronic blood loss, pregnancy, leukemia, drugs, hyperthyroidism

Question 7

Hemoglobin will typically be what?

Answer 7

Hematocrit/3

Question 8

What causes platelets to increase?

Answer 8

Essential thrombocytosis, myeloproliferative states, hemolysis, acute inflammatory states as an acute phase reactant

Question 9

When is the platelet count decreased?

Answer 9

ITP, HIT, aplastic anmeia, uremia, hypersplenism, bone marrow failure related to infection (sepsis)

Question 10

What are the signs and sx of low platelets?

Answer 10

Easy bruising, epistaxis, hematuria, menorrhagia

Question 11

What is included in a basic BMP?

Answer 11

Na, K, Cl, total CO2, BUN, Cr, Glucose, anion gap

Question 12

What is included in a complete/comprehensive BMP?

Answer 12

BMP + AST/ALT, bilirubin, alkaline phosphatase, Ca, albumin, total protein

Question 13

What causes hyponatremia?

Answer 13

Diarrhea, vomiting, HF, liver failure, SIADH

Question 14

What causes hypernatremia?

Answer 14

Dehydration (loss of water), Cushing’s syndrome, hyperaldosteronis, advanced age, pregnancy

Question 15

What causes high K?

Answer 15

AKI, CKD, metabolic acidosis, drugs like ACEI and ARBS

Question 16

What causes low K?

Answer 16

Vomiting, diarrhea, metabolic acidosis, diuretics, decreased intake, renal dysfunction

Question 17

What can cause high Cl?

Answer 17

Diarrhea, ATN, mineralocorticoid deficiency, drugs

Question 18

What can cause low Cl?

Answer 18

Vomiting, excess sweating, SIADH, mineralocorticoid excess

Question 19

What can cause a high BUN?

Answer 19

Acute GN, PCKD, GI bleeding (breakdown of Hb in gut), chronic nephritis, CKD

Question 20

What can cause low BUN?

Answer 20

Malnutrition, malabsorption, nephrotic syndrome, overhydration

Question 21

What causes high creatinine?

Answer 21

Renal dysfunction, shock, dehydration, HF, increased body mass

Question 22

What can cause low Creatinine?

Answer 22

Muscle wasting

Question 23

What is an anion gap?

Answer 23

Refers to concentration of unmeasured anions in blood such a protein, phosphate, sulphate, organic acids
AG = Na - (Cl + HCO3)
For HCO3 use the total CO2, can use serum BMP to estimate

Question 24

What can cause an increased anion gap?

Answer 24

Uremia, lactic acidosis, ketoacidosis, DKA, rhabo, alcohol abuse, drugs

Question 25

What can cause a low anion gap?

Answer 25

Cirrhosis, nephrotic syndrome, hemorrhage, lithium intoxication

Question 26

What causes hyperglycemia?

Answer 26

DM, Cushing’s syndrome, acromegaly, pheochromocytoma, glucagonoma, somatostatinoma, drugs such as glucocorticoids, pancreatic insufficiency

Question 27

What causes hypoglycemia?

Answer 27

Livery failure, excess use of insulin, acute alcohol intoxication, renal failure, sepsis, hypopituitarism, adrenal insufficiency, myxedema, insulinoma, drugs, extra pancreatic tumors

Question 28

What are examples of iron studies?

Answer 28

Serum iron, serum transferrin, transferrin saturation, serum ferritin