GI Bleed Flashcards
Questions based on CP 2 and App. CP 2 notes
Purpose of NM GI bleed study
detect and localize acute active or intermittent LOWER GI bleed
contraindications
none
what modality is best to detect upper GI bleeds?
endoscopy
causes of upper GI bleeds
- duodenal ulcer
- varices
- gastric ulcers
- esophagitis
- neoplasm
what is considered “upper” GI tract?
esophagus, stomach, duodenum
what is considered “lower” GI tract?
jejunum, ileum, colon
causes of lower GI bleeds
- diverticular disease
- angiodysplasia
- ulcerative colitis, IBD
- neoplasms
- Meckel’s
- ulcers
- drugs (anticoagulants, steroids, aspirin)
- avm (arteriovenous malformation)
what is the ligament of treitz?
band of tissue in abdomen that anchors duodenum and helps move contents along the GI tract
what differentiates “upper” and “lower” GI tract?
Whether it is above or below the Ligament of Treitz
upper GI bleeds usually = ____ stool
black tarry stool
= melena
lower GI bleeds usually = _____ stool
bright red stool
= hematochezia
symptoms of GI bleeds
- abdominal discomfort
- weight loss
- weakness, fatigue, dizziness
- blood in stool
- low RBC count/hematocrit
treatment for GI bleeds
- laparoscopic cauterization/bowel resection
- medication
- endoscopy
- angiography
colonic bleed appearance
periphery of the abdomen
small bowel bleed appearance
centre of the abdomen
activity found in the same location
think static vascular abnormalities
(I.e. aneurysm, angiodysplasia, hemangioma, etc.)
3 criteria for positive GI bleed
- focal activity where none was initially
- activity increases over time
- movement of activity that conforms to intestinal anatomy
modality best for upper GI bleeds
endoscopy + gastric aspiration
best modality to localize bleeds?
CT angiography
dose and RP
740-1110 MBq 99mTc-RBCs
normal appearance
heart, liver, spleen, great vessels, kidneys
positioning for GI bleed
lower border of liver to pubic symphysis
colby’s: xiphoid to pubic symphysis
advantage of in vivo labelling
used for patients that can’t receive blood products
disadvantage of modified in vivo
still more prone to iatrogenic interference
which has the best labelling efficiency?
in vitro
what can affect RBC tagging?
- excess or insufficient stannous ion
- improper labeling technique/timing
- iatrogenic sources
what are some iatrogenic sources?
- some medications
- iodinated contrast
- use of recent blood products
