2. GI BLEED
• Epidemiology
• The incidence of acute upper GI bleeding is ~100 per 100,000
adults per year.Upper GI bleeding is twice as common in men as in
women and increases with age .
• Clinical presentation
• The signs of bleeding in the digestive tract depend upon the site and
severity of bleeding. If blood is coming from the rectum or the lower
colon, bright red blood will coat or mix with the stool. The cause of
bleeding may not be serious, but locating the source of bleeding is
important. Slow bleeding may cause iron-deficiency anemia.
3. • Clinical presentation
• The signs of bleeding in the digestive tract
depend upon the site and severity of bleeding.
If blood is coming from the rectum or the lower
colon, bright red blood will coat or mix with the
stool. The cause of bleeding may not be
serious, but locating the source of bleeding is
important. Slow bleeding may cause iron-
deficiency anemia
4. • LGIB is defined as that occurring distal to the ligament (i.e. from the
jejunum, ileum, colon, rectum or anus) and presenting as either
hematochezia (bright red blood/clots or burgundy stools) or melena (black
tar like stool).
• Epidemiology
• The incidence of lower gastrointestinal bleeding is only one-fifth that of the
upper gastrointestinal tract and is estimated to be ~24 per 100,000 adults
per year. Male and older patients tend to suffer from more severe LGIB.
5. Clinical presentation
•Acute bleeding is defined as bleeding of 3 days' duration,
resulting in instability of vital signs, anemia, and/or the need
for blood transfusion.
•Chronic bleeding is defined as slow blood loss over a period of
several days or longer, presenting with symptoms of intermittent
melena or small hematochezia.
•Lower gastrointestinal bleeding is usually chronic.
6. GI Bleed
• Radiographic features
Upper endoscopy is the first-line investigation and allows for the treatment of the
bleeding using a variety of endoscopic techniques.
• CT
There are some values of using CT as the 'next step' technique in identifying a
bleeding source within the GIT following negative or failed endoscopy in the acute
setting 6.
7. Nuclear medicine
• Nuclear scintigraphy (Tc99m-labeled RBC scan) is the most
sensitive modality in detecting occult GI bleeding. However, it is
often unable to accurately localize the source or the exact site
of bleeding
8. •For decades radiologic evaluation of GI bleeding has been performed by using technetium 99m
(Tc) scintigraphy and fluoroscopic angiography. Tc scintigraphy can be performed with a sulfur
colloid– or red blood cell (RBC)– based radiopharmaceutical agent. It is the most sensitive
radiologic technique for the identification of active bleeding, enabling the detection of bleeding
•Unlike Tc-labeled sulfur colloid, which has a relatively short half-life (5–10 min), labeled
RBCs remain in the circulation, allowing intermittent imaging for up to 24 hours .
.
9. How is the Test Performed?
Method 1
• The RBCs are tagged with radioisotope in 1 of 2 ways.
• The first method involves removing blood from a vein.
• The red blood cells are separated from the rest of the blood sample. The
cells are then mixed with the radioactive material. The cells with the
radioactive material are considered "tagged." A short time later the
tagged RBCs are injected into one of your veins.
10. Method 2
The second method involves an injection of medicine. The medicine allows
the radioactive material to attach to your red blood cells. The radioactive
material is injected into a vein 15 or 20 minutes after you receive this
medicine.
11.
12. WHY IDEAL?
High sensitivity and capability for detection of intermittent bleeding
have made Tc scintigraphy the ideal examination for detecting
slow intermittent bleeding that cannot be identified by using other
methods.
13. LIMITATIONS
•The limitations of Tc scintigraphy include limited availability
and a delay of several hours before the examination is
initiated.
•Poor anatomic localization of the bleeding identified at RBC
scintigraphy may result in misdiagnoses (eg, colon vs small-
bowel bleeding right vs left colonic bleeding) and subsequent
errors at therapeutic interventions
