Chapter 11 WB Flashcards
a reaction due to fear of the examination is known as what type of reaction?
vasomotor
when a moderate reaction to contrast occurs, what drug is given first?
diphenhydramine (benadryl, antihistamine)
name the two negative contrast media that can be used
air and carbon dioxide
these two negative contrasts are not to be used in the vascular system because they can cause an
emboli
name the only inert contrast medium
barium
name the three reasons iodine is used in soluble contrast material
readily available, nonmetallic atomic number, and is easily exchangeable with other ions
use of a positive contrast medium _____ the organ density by using a substance with a _____ atomic number
increases; high
negative contrast media use a substance with a _____ atomic number to _____ the density of the organ
low; decrease
what must be obtained before injecting a patient with a contrast medium?
allergy history
in radiography, contrast means _____ difference
density
name four possible complications resulting from the use of barium
aspiration, perforation, sepsis, and shock
a patient who is flushed and has nausea is probably having a _____ reaction
mild
what laboratory value should be checked before any renal study with contrast media?
BUN, creatine
what chemical compound is eliminated and replaced with a hydroxyl group to obtain low osmolality contrast media?
carboxyl group
how much iodine concentration is needed for adequate opacity on radiographs?
300 mg/mL
what are two preexisting conditions that may be an indication of the patient experiencing and adverse reaction to contrast media?
food allergy and history of asthma (or renal insufficiency and cardiac disease)
name the seven characteristics which should be addressed before choosing a contrast medium
viscosity, type of ionic salt, iodine content, miscibility, persistence, toxicity, and osmolality
ionic monomers have _____ iodine atoms and _____ particles in solution for osmolality
3; 2
T/F: contrast media are pharmaceuticals
true
T/F: radiolucents decrease organ density
true
T/F: ultrasound uses radionuclides
false
T/F: air as a contrast medium can cause an embolus
true
T/F: radiopaques are also called negative contrast media
false
T/F: all soluble positive contrast media contain some form of iodine
true
T/F: a characteristic of radionuclides is the emission of radiation
true
T/F: iodine is easily exchangeable with other ions
true
T/F: all positive contrast media are absorbed by the body
false
