Equations

Question 1

A-a gradient

Answer 1

[150-PCO2/0.8]-PaO2
[FiO2*(Patm-PH2O)-(PaCO2/0.8)]-PaO2
Normal 5-10
Normal + hypoxic: low FiO2, low ventilation
High + hypoxic: VQ mismatch, diffusion defect, R>L shunt, increased O2 extraction
Increases with age

Question 2

Delta gap

Answer 2

Change in AG - change in HCO3 (AG low with lithium, high with MUDPILES)
<0.4: nl met acidosis
0.4-0.8: AG + nl met acidosis
0.8-2: AG met acidosis
>2: AG met acidosis + met alkalosis OR compensated resp acidosis

Question 3

FeNA

Answer 3

(PcrUna)/(PnaUcr) (prerenal<1%, intrinsic>1%, postrenal>4%)

Question 4

Serum osm

Answer 4

2Na + BUN/2.8 + Gluc/18 + ETOH/4.6

Question 5

Parkland burn formula

Answer 5

TBSA% * kg * 4mL (give 1st half in 8hrs, rest in 16hrs)

* 3mL in children

Question 6

Na correction for BG

Answer 6

+1.6 for every 100 BG over 100

Question 7

Winter’s/expected pCO2

Answer 7

1.5 * HCO3 + 8 +/- 2 (met acid)
0.7 * HCO3 + 20 +/- 5 (met alk)
Est < real: resp acidosis
Est > real: resp alkalosis

Question 8

MUDPILES

Answer 8

(met acidosis causes) Methanol, Uremia, DKA/AKA, Paraldehyde, Iron/INH, LA, Ethylene glycol, Salicylates

Question 9

GETSMASHED

Answer 9

(pancreatitis causes) Gallstones, ETOH, Trauma, Steroids, Mumps, Autoimmune, Scorpion, HyperTG, ERCP, Drugs

Question 10

Arsenic antidote

Answer 10

BAL, DMSA

Question 11

CCB antidote

Answer 11

Calcium, glucagon, insulin

Question 12

Cyanide antidote

Answer 12

Hydroxycobalamin, stuff that causes methemoglobinemia

Question 13

Lead antidote

Answer 13

BAL, DMSA, dimercaprol, EDTA

Question 14

Mercury antidote

Answer 14

BAL, DMSA

Question 15

Organophosphate antidote

Answer 15

2-PAM, atropine

Question 16

Cholinergic antidote

Answer 16

Atropine

Question 17

Fibular head fx > nerve change

Answer 17

Peroneal, foot drop

Question 18

Humerus midshaft fx > nerve change

Answer 18

Radial, wrist drop

Question 19

Medial epicondyle fx > nerve change

Answer 19

Ulnar

Question 20

Achilles reflex

Answer 20

S1

Question 21

Patellar reflex

Answer 21

L2-4 (primarily L4)

Question 22

Brachioradialis reflex

Answer 22

C5-6

Question 23

Biceps reflex

Answer 23

C5-6

Question 24

Triceps reflex

Answer 24

C6-7 (primarily C7)

Question 25

Magnesium antidote

Answer 25

Calcium

Question 26

DiGeorge mnemonic

Answer 26

CATCH 22 (Cardiac abnl, Abnl facies, Thymic absence, Cleft palate, Hypocalcemia, Chr22)

Question 27

If you have pre-test odds and a + LR, what are the post-test odds and probability?

Answer 27

Post Odds = Pre Odd * + LR | Post Probability = Post Odds / (1 + Post Odds)

Question 28

+ LR =

Answer 28

Sensitivity / (1 - Specificity)

Question 29

- LR =

Answer 29

(1 - Sensitivity) / Specificity

Question 30

K correction for pH

Answer 30

-0.6 for every 0.1 below pH of 7.4

Question 31

Can't give what BP meds to WPW?

Answer 31

(ABCD) Adenosine, BB, CCB, Digoxin

Question 32

Sulfa containing drugs

Answer 32

(Popular FACTSSS) Probenecid, Furosemide, Acetazolamide, Celecoxib, Thiazides, Sulfonamides, Sulfasalazine, Sulfonylureas

Question 33

MAP equation

Answer 33

DBP + 1/3(SBP-DBP)

Question 34

Drug causes of erythema multiforme

Answer 34

(SOAPS) Sulfa, Oral hypoglycemics, Anticonvulsants, Penicillin, nSaids