R5 Flashcards
(28 cards)
which opiate is most nonionized at physiologic ph?
alfentanil (89%)
is moderately lipid soluble so is VERY fast and short acting
plasma-brain equilibrium time is 1.1minutes!
primary determinant of opiate onset and duration of action?
lipid solubility
lipid solubtility of fentanyls
al: 128
su: 1700
fent: 816
ESRD electrolyte changes
anemia (decreased EPO)
HYPO: calcemia (can’t reabsorb)
HYPER: kalemia, magnesia, lipidemia, tension, phosphatemia, uremia (AMS, platelet dysfunction)
why does liver disease result in decreased vitamin K levels?
decreased bile salt production, which are required for vitamin K absorption from the gut
why cant opiates be used as solo anesthetics?
ceiling effects -> recall and awareness
remi and fentanyl can have up to 80% reduction. Sufentanil can but needs 10x more
what beta blocker is metabolized by RBC esterases?
esmolol
cardioselective (B1) beta blockers
BEAM bisoprolol esmolol atenolol metoprolol
ratio of labetolol potency with PO/IV
alpha to beta
IV: 1:7
PO: 1:3
carvedilol is the only other common BB with alpha antagonism
what BB is metabolized by kidney?
atenolol is ONLY one
ATNelol
what is fenoldopam?
Dopamine 1 agonist -> peripheral vasodilation ia camp stimulation -> reduces preload AND afterload. Stimulates diuresis and naturesis. Can stimulate kidney perfusion while treating HTN
what reflects least amount of ultrasound beam reflection?
blood or other tissue with high water content (effusions, cyst)
air actually reflects ultrasound beams well -> use gel!
what determines acoustic impedance during ultrasound
density and propagation speed of sound
arterial oxygen content formula
CaO2 = (SaO2 * 1.36 * Hgb) + (PaO2 * 0.03)
partial pressure of oxygen at which 50% of hgb is saturated
normal P50 is 27%
weight is more reliable than pressure for which two gases?
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
E-sized FULL gas cylinders
O2: 660 NO: 1590 CO2: 1590 Helium: 500 Air: 625
what does engiotensin converting enzyme do?
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
what is aldosterone’s action?
promotes Na and H2O retention in kidney via activation of Na/K pumps in distal tubule
why do ACE inhibitors cause a decrease in GFR in setting of hypoperfusion?
decrease in efferent arteriolar resistance.
purposeful response after repeated or painful stimulus
deep sedation
How to calculate and read FeNa
UNa * PCr / PNa * UCr
<1% = prerenal >2% = intra/postrenal
chronic management of CHR
afterload reduction: ACEi, BB, spironolactone
volume control: fluid and diuretic management
when to continue DAPT for 12 months, regardless of type of stent?
if patients underwent PCI for ACS (can stop at 6 months if high risk of severe bleeding)
