Lower GI Bleeding, C50 P334-337

Question 1

What is the definition of
lower GI bleeding?
P334

Answer 1

Bleeding distal to the ligament of Treitz;

vast majority occurs in the colon

Question 2

What are the symptoms?

P334

Answer 2

Hematochezia (bright red blood per
rectum [BRBPR]), with or without
abdominal pain, melena, anorexia, fatigue,
syncope, shortness of breath, shock

Question 3

What are the signs?

P335

Answer 3

BRBPR, positive hemoccult, abdominal

tenderness, hypovolemic shock, orthostasis

Question 4

What are the causes?

P335

Answer 4

Diverticulosis (usually right-sided in
severe hemorrhage), vascular ectasia,
colon cancer, hemorrhoids, trauma,
hereditary hemorrhagic telangiectasia,
intussusception, volvulus, ischemic colitis,
IBD (especially ulcerative colitis),
anticoagulation, rectal cancer, Meckel’s
diverticulum (with ectopic gastric
mucosa), stercoral ulcer (ulcer from hard
stool), infectious colitis, aortoenteric
fistula, chemotherapy, irradiation injury,
infarcted bowel, strangulated hernia, anal
fissure

Question 5

What medicines should be
looked for causally with a
lower GI bleed?
P335

Answer 5

Coumadin®, aspirin, Plavix®

Question 6

What are the most common
causes of massive lower GI
bleeding?
P335

Answer 6

1. Diverticulosis

2. Vascular ectasia

Question 7

What lab tests should be
performed?
P335

Answer 7

CBC, Chem-7, PT/PTT, type and cross

Question 8

What is the initial treatment?

P335

Answer 8

IVFs: lactated Ringer’s; packed red blood
cells as needed, IV x 2, Foley catheter to
follow urine output, d/c aspirin, NGT

Question 9

What diagnostic tests should
be performed for all lower
GI bleeds?
P335

Answer 9

History, physical exam, NGT aspiration
(to rule out UGI bleeding; bile or blood
must be seen; otherwise, perform EGD),
anoscopy/proctoscopic exam

Question 10

What must be ruled out in
patients with lower GI
bleeding?
P335

Answer 10

Upper GI bleeding! Remember, NGT
aspiration is not 100% accurate (even if
you get bile without blood)

Question 11

How can you have a UGI
bleed with only clear succus
back in the NGT?
P335

Answer 11

Duodenal bleeding ulcer can bleed distal
to the pylorus with the NGT sucking
normal nonbloody gastric secretions! If
there is any question, perform EGD

Question 12

What would an algorithm
for diagnosing and treating
lower GI bleeding look like?
P336 (picture)

Answer 12

(see picture)

Question 13

What is the diagnostic test
of choice for localizing a
slow to moderate lower GI
bleeding source?
P336

Answer 13

Colonoscopy

Question 14

What test is performed to
localize bleeding if there is
too much active bleeding to
see the source with a
colonoscope?
P337

Answer 14

A-gram (mesenteric angiography)

Question 15

What is more sensitive for a
slow, intermittent amount of
blood loss: A-gram or tagged
RBC study?
P337

Answer 15

Radiolabeled RBC scan is more sensitive
for blood loss at a rate of ≥ 0.5 mL/min
or intermittent blood loss because it
has a longer half-life (for arteriography,
bleeding rate must be ≥ 1.0 mL/min)

Question 16

What is the colonoscopic
treatment option for bleeding
vascular ectasia or polyp?
P337

Answer 16

Laser or electrocoagulation; local

epinephrine injection

Question 17

What is the treatment if
bleeding site is KNOWN and
massive or recurrent lower
GI bleeding continues?
P337

Answer 17

Segmental resection of the bowel

Question 18

What is the surgical
treatment of massive lower
GI bleeding WITHOUT
localization?
P337

Answer 18

Exploratory laparotomy with intraoperative
enteroscopy and total abdominal
colectomy as last resort

Question 19

What percentage of cases
spontaneously stop bleeding?
P337

Answer 19

80%–90% stop bleeding with resuscitative
measures only (at least temporarily)

Question 20

What percentage of patients
require emergent surgery
for lower GI bleeding?
P337

Answer 20

Only ≈10%

Question 21

Does melena always signify
active colonic bleeding?
P337

Answer 21

NO—the colon is very good at storing
material and often will store melena/
maroon stools and pass them days later
(follow patient, UO, HCT, and vital signs)

Question 22

What is the therapeutic
advantage of doing a
colonoscopy?
P337

Answer 22

Options of injecting substance
(epinephrine) or coagulating vessels is an
advantage with C-scope to control bleeding

Question 23

What is the therapeutic
advantage of doing an
A-gram?
P337

Answer 23

Ability to inject vasopressin and/or
embolization, with at least temporary
control of bleeding in > 85%