Chemistry

Question 1

SPEP - Acute inflammation

Answer 1

Decreased albumin
Increased Alpha 1
Increased Alpha 2

Question 2

SPEP - Chronic Inflammation

Answer 2

Decreased albumin
Increased Alpha 1
Increased Alpha 2
Increased Gamma (polyclonal)

Question 3

SPEP - Hepatic Cirrhosis

Answer 3

Decreased albumin
Decreased Alpha 1
Decreased Alpha 2
Decreased Beta
Beta-Gamma bridging

Question 4

SPEP - Nephrotic Syndrome

Answer 4

Decreased albumin
Decreased Alpha 1
Increased Alpha 2
Decreased Beta
Decreased Gamma

Question 5

Cushing Workup

Answer 5

1) 1 mg screening test

2) Low dose dex - if fails to suppress then Cushing syndrome

3) High dose dex
- If fails to suppress cortisol, then adrenal source or ectopic
- If suppresses cortisol, pituitary source (Cushing disease)

4) ACTH test
- if ectopic, high ACTH
- If adrenal, low ACTH

Question 6

Anion Gap - Equation and normal

Answer 6

AG = Na - Cl - HCO3

Normal 3-11

Question 7

Causes for Anion Gap acidosis

Answer 7

“MUDPILES”

Methanol
Uremia
DKA
Paraldehyde
Iron/Isoniazid
Lactic Acid
Ethanol/Ethylene glycol
Starvation/Salicylates

Question 8

Acute renal failure - Pre-renal

BUN/Cr
Urine Na
Urine Osm

Answer 8

Kidneys trying pull everything back

***BUN/Cr > 20

Urine Na < 20

Urine Osm > 500

Question 9

Acute renal failure - Intrinsic

BUN/Cr
Urine Na
Urine Osm

Answer 9

BUN/Cr < 20

Urine Na > 20

Urine Osm < 350

Question 10

Acute renal failure - Post-renal

BUN/Cr
Urine Na
Urine Osm

Answer 10

Kidneys trying to flush out obstruction

BUN/Cr < 20

***Urine Na > 40

Urine Osm < 350

Question 11

Three causes of hypocalcemia

Answer 11

1) Low PTH

2) Low Mg (which blocks PTH release)

3) Low Vitamin D

Question 12

Preganancy changes
CBC
Serum electrolytes
Urine
Thyroid
Coags

Answer 12

CBC - dilutional RBC decrease

Electrolytes - lower serum sodium and osmolality

Urine:
GFR increases
Lower serum Cr and BUN
High urine Cr, uric acid, glucose

Thyroid:
Increased TBG, T3 and T4

Coags:
Increased fibrinogen
Decreased protein S

Question 13

Opiate metabolites
- Morphine
- Codeine
- Heroin
- Oxycodone

Answer 13

Morphine -> hydromorphone

Codeine -> hydrocodone + morphine

Heroin -> 6-MAM -> hydrocodone + morphine

Oxycodone -> oxymorphone

Question 14

PCP - False positives

Answer 14

Dextromethorphan

Question 15

LSD - False positives

Answer 15

Sertraline, Amitriptyline, Verapamil

Question 16

Barbituates - False positives

Answer 16

Phenytoin

Question 17

Amphetamines - False positives

Answer 17

Ephedrine
Pseudoephedrine
Phenylephrine
MDMA

Question 18

Lipid Measurements:
Total cholesterol, LDL, HDL, TGs

Answer 18

Total cholesterol - direct
(cholesterol esterase + H2O2)

HDL - direct
(precipitate out LDL ad VLDL)

LDL - calculated
(Total - HDL - TGs/5)

TGs - direct
(cleave, react glycerol with H2O2)

Question 19

Barbituate - mechanism of action

Answer 19

Increase duration of Cl- channel opening (GABA receptor)

Question 20

Benzo - - mechanism of action

Answer 20

Increase frequency of Cl- channel opening (GABA)

Question 21

Serum osmol gap

Answer 21

Calculated osm = (2 x Na) + (glucose / 18) + (BUN / 2,8)

Actual osm - calc

Question 22

21 hydroxylase defic

Answer 22

Androgens - up
Glucocorticoids - down
Mineralcorticoids - down

No movement “down”
Everything shunts to testosterone

Question 23

17a-hydroxylase defic

Answer 23

Androgens - down
Glucocorticoids - up
Mineralcorticoids - up

No movement “right”
Shunting towards minerals (but some gluco too)

Question 24

11b-hydroxylase defic

Answer 24

Androgens - up
Glucocorticoids - down
Mineralcorticoids - weak up

No final “down”
Only thing can make is androgens