R5

Question 1

which opiate is most nonionized at physiologic ph?

Answer 1

alfentanil (89%)

is moderately lipid soluble so is VERY fast and short acting

plasma-brain equilibrium time is 1.1minutes!

Question 2

primary determinant of opiate onset and duration of action?

Answer 2

lipid solubility

Question 3

lipid solubtility of fentanyls

Answer 3

al: 128
su: 1700
fent: 816

Question 4

ESRD electrolyte changes

Answer 4

anemia (decreased EPO)
HYPO: calcemia (can’t reabsorb)
HYPER: kalemia, magnesia, lipidemia, tension, phosphatemia, uremia (AMS, platelet dysfunction)

Question 5

why does liver disease result in decreased vitamin K levels?

Answer 5

decreased bile salt production, which are required for vitamin K absorption from the gut

Question 6

why cant opiates be used as solo anesthetics?

Answer 6

ceiling effects -> recall and awareness

remi and fentanyl can have up to 80% reduction. Sufentanil can but needs 10x more

Question 7

what beta blocker is metabolized by RBC esterases?

Answer 7

esmolol

Question 8

cardioselective (B1) beta blockers

Answer 8

BEAM
bisoprolol
esmolol
atenolol
metoprolol

Question 9

ratio of labetolol potency with PO/IV

Answer 9

alpha to beta
IV: 1:7
PO: 1:3

carvedilol is the only other common BB with alpha antagonism

Question 10

what BB is metabolized by kidney?

Answer 10

atenolol is ONLY one

ATNelol

Question 11

what is fenoldopam?

Answer 11

Dopamine 1 agonist -> peripheral vasodilation ia camp stimulation -> reduces preload AND afterload. Stimulates diuresis and naturesis. Can stimulate kidney perfusion while treating HTN

Question 12

what reflects least amount of ultrasound beam reflection?

Answer 12

blood or other tissue with high water content (effusions, cyst)

air actually reflects ultrasound beams well -> use gel!

Question 13

what determines acoustic impedance during ultrasound

Answer 13

density and propagation speed of sound

Question 14

arterial oxygen content formula

Answer 14

CaO2 = (SaO2 * 1.36 * Hgb) + (PaO2 * 0.03)

Question 15

partial pressure of oxygen at which 50% of hgb is saturated

Answer 15

normal P50 is 27%

Question 16

weight is more reliable than pressure for which two gases?

Answer 16

NO and CO2 (and propane)

NO: Pressure gauge remains constant until only 400L (full is 1590L) remains). Full is 8.8kg pressure 745 psig, empty is 5.9 kg

Question 17

E-sized FULL gas cylinders

Answer 17

O2: 660
NO: 1590
CO2: 1590
Helium: 500
Air: 625

Question 18

what does engiotensin converting enzyme do?

Answer 18

catalyzes the degradation of bradykinin, which promotes vasodilation by increasing production of arachidonic acid metabolites and NO

RAS: renin released by JGA in response to decreased renal perfusion pressure, reduced sodium in macula densa, or sympathetic activation. Renin cleaves angiotensinogen to AT1. ACE then cleaves AT2 from AT1

AT2 increases Na retention via aldosterone stimulation and renal vasoconstriction. Increases fluid retention via stimulation of ADH from PP

Question 19

what is aldosterone’s action?

Answer 19

promotes Na and H2O retention in kidney via activation of Na/K pumps in distal tubule

Question 20

why do ACE inhibitors cause a decrease in GFR in setting of hypoperfusion?

Answer 20

decrease in efferent arteriolar resistance.

Question 21

purposeful response after repeated or painful stimulus

Answer 21

deep sedation

Question 22

How to calculate and read FeNa

Answer 22

UNa * PCr / PNa * UCr

<1% = prerenal 
>2% = intra/postrenal

Question 23

chronic management of CHR

Answer 23

afterload reduction: ACEi, BB, spironolactone

volume control: fluid and diuretic management

Question 24

when to continue DAPT for 12 months, regardless of type of stent?

Answer 24

if patients underwent PCI for ACS (can stop at 6 months if high risk of severe bleeding)

Question 25

NSAIDs inhibit what?

Answer 25

afferent renal artery vasodilation

also COX, preventing formation of prostaglandins and thromboxane

TXA: produced by platelets, promotes platelet activation
PGE: protective effects in GI and renal systems. cause vasodilation of afferent -> increase renal blood flow

Question 26

P450 34A system is involved in metabolism of

Answer 26

tramadol, benzos, TCAs, alfentanil, antipsychotics

inhibited by grapefruit and protease inhibitors
activated by st. john’s wort and anticonvulsants

Question 27

patients at highest risk of latex allergy

Answer 27

healthcare workers, multiple surgery, atopy, allergies to tropical or stone fruits, chestnuts.

if suspected - draw mast cell tryptase level within 15-30m

Question 28

MC involved in perioperative anaphylaxis

Answer 28

NMBAs, latex, antibiotics