Exam 2 - GI Contrast Flashcards
what is the example given of negative contrast for gi studies?
gas/air
what are the 3 examples given for positive contrast medias used for gi studies?
ionic-iodinated
barium sulfate
non-ionic iodinated
what kind of contrast media is ionic iodinated?
early water soluble iodinated (iodine-based) contrast media
why is ionic iodinated contrast media not commonly used?
it has a high osmolality & has a higher degree of adverse reactions
what studies may use barium sulfate?
esophagrams, upper gis, gastrograms, & colonograms
what are the cons of using barium sulfate?
it’s not absorbed by the gi tract, so leakage into the pleural/peritoneal cavities can cause pleuritis/peritonitis with severe adhesions & granulomas
why is aspirating barium sulfate so bad?
small amount is relatively inert, but a large amount can cause inflammation leading to lung lobectomies & death
what kind of contrast media is non-ionic iodinated?
lower osmolar compound than ionic, so it has fewer adverse reactions
how can non-ionic iodinated media be given safely?
IV, intrathecally, orally
safe in pleural & peritoneal cavities
what are the cons of using non-ionic iodinated media?
aspiration will cause pulmonary edema
acute & late adverse reactions are possible
why should you put your patient in left lateral recumbency if using negative contrast media?
helps decrease the risk of fatal embolism
what gases lower the risk of an air embolism associated with using negative contrast media?
CO2 & NO2 - more soluble gases
what is this study? when may you use it?
pneumocolonogram
- determine location of the colon
- small intestinal dilation vs. colon
- location of foreign bodies
how would you perform this study?
insert air into the rectum using a red rubber catheter & radiograph the patient immediately (VD & opposite laterals as needed)
what is this study? when may you use it?
barium enema/colonogram
- determine location of colon
- small intestinal dilation vs. colon
- location of foreign bodies
- colonic torsion/stricture
how would you perform this study?
insert barium into the colon using a red rubber
radiograph immediately
what must be done to do a gastrogram/pneumogastrogram?
fast the patient for 12-24 hours
how would you perform this study?
administer barium/air via an orogastric tube & radiograph immediately
what is this study? when may you use it?
gastrogram/pneumogastrogram
- foreign body, mass
- identify the location of the stomach
when is an upper gi study indicated?
vomiting without evidence of obstruction on survey rads, motility disorder, evaluate mass identified on rads/palpation, & concern for ulceration
what are contraindications of an upper gi study?
PERFORATION - no barium!!!!
intractable vomiting, evidence of surgical lesions, fractious animal, or planning to do an abdominal ultrasound
what is the purpose of an upper gi study?
using a positive contrast medium to evaluate the stomach & small intestines
what two mediums are typically used for upper gi studies?
barium sulfate & non-ionic iodinated
how is an upper gi study performed?
give medium via syringe or orogastric tube
what is the time that the contrast media should reach the colon in dogs?
1-4 hours
what is the time that the contrast media should reach the colon in cats?
1 hour
at what times should radiographs be taken if doing an upper gi study on a dog?
0 minutes, 30 minutes, 60 minutes, 120 minutes, & 240 minutes
when should the stomach be empty in an upper gi study on a dog?
2 hours - begins to empty ~15 minutes in normal animals
when should the stomach be empty in an upper gi study on a cat?
30 minutes
at what times should radiographs be taken if doing an upper gi study on a cat?
0 minutes, 30 minutes, 60 minutes
when does your upper gi study end?
mechanical obstruction is identified or the contrast is in the colon & the stomach is empty
what are the pitfalls of upper gi studies?
insufficient contrast medium given
failure to complete study
failure to note times on images
what must be noted on radiographic images of upper gi studies?
the time!!!!
what obstructional pattern is seen here?
intraluminal pattern - foreign body or intraluminal mass
what obstructional pattern is seen here?
mass in wall & stricture
what obstructional pattern is seen here?
extramural - mass outside the wall causing compression/displacement
should you do a contrast procedure before an ultrasound?
no
