1. Lower GI Bleeding
4/6/11

2. LGIB Distal to ligament of Treitz
Annual incidence rate of 20.5/100,000
Male predominance
Incidence of significant bleeding increases with age
May suggest changes associated with the small intestine and colon
Reflects the prevalence of diverticulosis and angiodysplasia in the elderly

3. LGIB May present as melena or hematochezia
Melena typically suggests bleeding from a more proximal source (colon or small intestine)
Hematochezia suggests left colonic, rectal, or anal sources
Upper gastrointestinal hemorrhage may present with rectal bleeding given blood’s cathartic effect and rapid intestinal transit (10-15% of cases)

4. LGIB Most often the intestinal bleeding resolves spontaneously
Once it resolves, investigations should begin to identify the potential sources
On occasion, the intestinal hemorrhage does not resolve
Creates hemodynamic compromise
Ongoing hemorrhage demands aggressive medical and surgical management
Oftentimes patients are plagued with significant comorbidities that complicate their individual resuscitation
Comorbidities must be considered in the diagnostic and therapeutic phases of the care plan
Current increased patient exposure to antiplatelet therapy associated with treatment of cardiovascular conditions may increase the comorbid challenges in patients with lower gastrointestinal massive hemorrhage

5. Etiology Diverticula Angiodysplasia Ischemic colitis
Inflammatory bowel disease
Intestinal tumors or malignancies
NSAID-related nonspecific colitis
Meckel’s diverticulum
Anorectal diseases

6. Diverticular disease
Outpouchings of the mucosa and submucosa through defects in the muscular layer of the bowel at sites of penetration of the vasa recta
Thinning of the media in the vasa recta predisposes to intraluminal rupture: focal injury may occur from trauma related to a fecalith
incidence spans a range of 15% to 48%
relatively rare event affecting only 4%–17% of patients with diverticulosis

7. Diverticular disease
Operative management is indicated when bleeding continues unabated and is not amenable to angiographic or endoscopic therapy
Should be considered in patients with recurrent bleeding localized to the same colonic segment
In a stable healthy patient, the operation consists of a segmental bowel resection (usually a right colectomy or sigmoid colectomy) followed by a primary anastomosis

8. Angiodysplasia
Thin-walled arteriovenous communications located within the submucosa and mucosa of the intestine
May be congenital or acquired, isolated or multiple
In the acquired form, distortions of the postcapillary venules may arise as a degenerative lesion associated with increases in intraluminal pressure
Results in thickening and ectasia
The vessels eventually entangle as tufts within the submucosa and erode into the mucosa proper

9. Angiodysplasia Colonoscopic criteria
Mucosal surface contains a cherry red lesion that is typically flat
Greater than 2 mm in size
Have a “fern-like” appearance
A central feeding vessel is not always visible

10. Occult Hemorrhage Occurs infrequently
no more than 5% of all patients admitted with LGI massive hemorrhage
Frequent recurrences create chronic anemic states in patients and require occasional admissions for transfusions
May harbor angiodysplasias in the small intestine or right colon
May benefit from small bowel contrast radiography or capsule endoscopy
Elective angiography with cecal magnification may reveal small angiodysplasias

11. Occult Hemorrhage
If the hemorrhage recurs and investigations fail to reveal the source, a variety of provocative diagnostic angiographic studies have been described
Most studies prefer to incite bleeding using either heparin or thrombolytics
Once the site of bleeding is identified, it may be difficult to control without surgery
Prepare and hold an operating room
Once the location is identified, a superselective catheter is left in the distal artery
During surgery, the surgeon can palpate the catheter within the vessel and direct the surgical resection

12. Initial Assessment
Establish IV access (large bore) and start IV fluids
restore volume and replete red blood cell deficiencies
Labs
CBC, electrolytes, coags, type and cross
All coagulopathies require reversal!
NG tube placed will screen for the presence of upper gastric sources for bleeding
Kovacs and Jensen noted 17.9% of LGI hemorrhage presentations involved an upper gastrointestinal source
NG tube is effective in detecting prepyloric hemorrhage

13. Evaluation Digital anorectal examination and anoscopy
Rigid proctosigmoidoscopy will allow the examiner to evacuate the rectum of blood and clots
Excludes internal hemorrhoids, anorectal solitary ulcers, neoplasms, and colitis
Colonoscopy and angiography offer therapeutic intervention
Nuclear scanning is purely diagnostic

14. Evaluation subdivide patients into 3 general clinical categories
minor and self-limited
major and self-limited
major and ongoing
Major ongoing hemorrhage requires prompt intervention with angiography or surgery
Minor, self-limited may undergo colonic lavage and colonoscopy within 24 hours
Major, self-limited need diagnostic tests to determine if they require prompt therapy or observation

15. Radionuclide imaging Detects the slowest bleeding rates
0.1–0.5 mL/min
More sensitive than angiography
Unfortunately cannot reliably localize the site of hemorrhage
The specificity of small bowel versus large intestine bleeding does not reliably compare with angiography
Two general techniques
technetium sulfur colloid scans
99mTc pertechnetate-tagged RBCs

16. Radionucleotide imaging
Immediate positive blush (within the first 2 minutes of scanning)
highly predictive of a positive angiogram (60%)
predictive for surgery in 24%
If study did not demonstrate a blush
highly predictive of a negative angiogram (93%)
the need for surgery decreased to 7%

17. Colonoscopy
If the patient appears stable with self-limited hemorrhage, colonoscopy is the preferred diagnostic study
Major benefit depends on ability to provide a definitive localization of ongoing active bleeding and the potential for therapy
Many landmarks for colonoscopy may be obscured during hemorrhage
Once the endoscopist highlights a bleeding source, the region requires a tattoo to mark the site
If the hemorrhage continues and fails medical management, the tattoo assists in localizing the hemorrhage
Therapeutic armamentarium i
thermal agents such as heater probes, bipolar coagulation, and laser therapy
Injection therapy uses topical and intramucosal epinephrine
Mechanical therapy includes endoscopically applied clips

18. Angiography Diagnostic and therapeutic
Acute, major hemorrhage with ongoing bleeding requires emergency angiography
Patients with an early blush during nuclear scintigraphy may benefit from therapeutic angiography
May define a potential source for hemorrhage in occult and recurrent gastrointestinal hemorrhage
Requires a hemorrhage rate of at least 1 mL/min
Yields range from 40% to 78%

19. Angiography Highly accurate localization provides for focused therapy
Intraarterial vasopressin infusion
0.2 U/min up to 0.4 U/min
Systemic effects and cardiac impact may limit maximizing the dosage
Controls bleeding in 91% of patients
Bleeding may recur in up to 50% of patients
Arterial embolization
Superselective mesenteric angiography with microcatheters in the vasa recta
Vessels as small as 1 mm
Risk of intestinal infarctions of larger selective vessels may exceed 20%
Provides immediate arrest of the bleeding
Combination of agents to control bleeding
Gelfoam pledgets, coils, and polyvinyl alcohol particles
Arteriography also has complications
arterial thrombosis, distant arterial emboli, and renal toxicity from dye

20. Operative therapy Few patients currently require surgical treatment
Hemodynamically unresponsive to initial resuscitation
Site of hemorrhage localized, but available therapeutic interventions fail to control the bleeding
Patient mortality increases with their transfusion requirements
Once reaches 6–7 units and the hemorrhage remains ongoing, surgical intervention becomes eminent
First objective in surgery focuses on the location of the intraluminal blood with the goal of segmentally isolating the possible sources of bleeding
if no source appears obvious, may consider intestinal enteroscopy

21. Operative therapy
If the source of bleeding cannot be found, and it appears to arise from the colon, the surgeon should perform a subtotal or total colectomy
Stable patients will tolerate a primary ileosigmoid or ileorectal anastomosis
Unstable patients require an end ileostomy with closure of the rectal stump or a mucous fistula
Once stable, the patient may return for ileostomy closure.
The rectum and sigmoid colon require reexamination endoscopically to assure no bleeding persists.

22. Algorithm