IV Contrast Media & Dyes Flashcards
What are 3 osmotic Effects of IV contrast
Decrease in RBF
Decreased GFR
Osmotically-induced diuresis (dehydrating effect)
3 classifications of ICM reactions
Idiosyncratic
Nonidiosyncratic
Contrast-induced nephropathy (CIN)
Characteristics of Idiosyncratic Reactions
W/in 20min
Anaphylacatoid
Common in previous ICM reaction, asthma, food/drug/environ. allergy
Symptoms of Idiosyncratic reactions
hives
n/v
diaphoresis
laryngeal edema
bronchospasm
HTN/HOTN
tachy/brady
seizures
Nonidiosyncratic reactions may be _____ and should not be used in _______
the symptoms resemble _________
delayed; in pregnancy (nonionic agent preferred)
flu-like
Nonidiosyncratic cardiovascular effects
negative inotrope
vasovagal
may precipitate angina
syncope
vasodilation
HOTN
lower threshold for V-arrhythmia
risk for cardiac arrest
hyperosmolar IVF w/ICM may cause HTN & pulm edema
other nonidiosyncratic reactions include
extravasation
seizure
exacerbate other diseases
contrast-induced nephropathy causes
> 50% elevation in creatinine
renal vasoconstriction
increased 02 free radicals
increased blood viscosity & O2 consumption
what elevates the risk of CIN
pre-existing renal insufficiency
DM
CHF IV
Elderly
NSAIDS
Repeated doses
sepsis
anemia
hypovolemia
what class of medicationos can help with contrast reactions
histamine blockers, IVF (NS, LR)
What medications can help with a CIN reaction
N-acetylcysteine
Theophylline
Sodium Bicarb
in management of CIN, it is not recommended to hold______ or ____
BUT______&______ should be avoided
routine diuretics or ACEI
mannitol & furosemide
How to prevent contrast s/e
corticosteroids, H-2 blockers (pepcid, famotidine_, H-1 blocker (diphenhydramine)
Indocyanine green (ICG) absorption and emission is ____ and should be reconstituted with_______
800-850nm
sterile water(unstable in aqueous solutions)
Dose of Iindocyanine Green
Adults 5mg
Peds 2.5mg
MAX 2mg/kg
Indigo Carmine absorption and excitation is ______
with a dose of
MAX 615nm
5mL
Indigo Carmine may cause
Alpha adrenergic stimulation (transient HTN)
Methylene Blue absorption and excitation peaks at______ and is incompatible with_____
700nm
normal saline
Methylene Blue is a pregnaancy category_____ and should be avoided in patients with_______
X
G6PD deficiency, hepatic/renal impairment/antidepressant drugs
Methylene blue is used to treat______(ferrous state) and can combine to ______to form cyanmethemoglobin
methemoglobinemia; cyanide
methylene blue is sometimes used as a_________by inhibiting nitric oxide synthase and guanyl cyclase reducing formation of cGMP
vasopressor
What is the dose of methylene blue
0.25-2mg/kg IV
infusion up to 3mg/kg/hr
administer slowly over 5-30min
What are the adverse effects of methylene blue
MB is a potent MAOI(leading to fatal serotonin toxicity-HTN crisis)
Hemolysis
Hypersensitive reaction
HTN
Angina
Reduced mesenteric & cutaneous perfusion
oxyhemoglobin absorbs more___
deoxyhemoglobin absorbs more______
more infrared 940nm
more red 660nm
IV dyes w/lower absorption peaks decrease the absorption ratio of red & infrared wavelengths, giving a false
low oxygen saturation reading
