Download - Lower Gi Bleed 4611

7/29/2019 Lower Gi Bleed 4611

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LOWER GI BLEEDING

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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


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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 bloodscathartic effect and rapid intestinal transit (10-

15% of cases)


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LGIB

Most often the intestinal bleeding resolvesspontaneously

Once it resolves, investigations should begin to identifythe potential sources

On occasion, the intestinal hemorrhage does notresolve Creates hemodynamic compromise

Ongoing hemorrhage demands aggressive medicaland surgical management

Oftentimes patients are plagued with significantcomorbidities that complicate their individualresuscitation

Comorbidities must be considered in the diagnosticand therapeutic phases of the care plan

Current increased patient exposure to antiplatelet


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Etiology

Diverticula

Angiodysplasia

Ischemic colitis

Inflammatory bowel disease

Intestinal tumors or malignancies

NSAID-related nonspecific colitis

Meckels diverticulum

Anorectal diseases


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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 rectapredisposes 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


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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


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Angiodysplasia

Thin-walled arteriovenous communications

located within the submucosa and mucosa of

the intestine

May be congenital or acquired, isolated ormultiple

In the acquired form, distortions of the

postcapillary venules may arise as adegenerative lesion associated with increases

in intraluminal pressure

Results in thickening and ectasia

The vessels eventually entangle as tufts within


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Angiodysplasia

Colonoscopic criteria

Mucosal surface

contains a cherry red

lesion that is typically flatGreater than 2 mm in

size

Have a fern-like

appearance

A central feeding vessel

is not always visible


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Occult Hemorrhage

Occurs infrequently

no more than 5% of all patients admitted with LGImassive hemorrhage

Frequent recurrences create chronic anemic

states in patients and require occasionaladmissions for transfusions

May harbor angiodysplasias in the small intestineor right colon

May benefit from small bowel contrastradiography or capsule endoscopy

Elective angiography with cecal magnification mayreveal small angiodysplasias


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Occult Hemorrhage

If the hemorrhage recurs and investigations fail toreveal the source, a variety of provocativediagnostic angiographic studies have beendescribed

Most studies prefer to incite bleeding using eitherheparin or thrombolytics

Once the site of bleeding is identified, it may bedifficult to control without surgery

Prepare and hold an operating room

Once the location is identified, a superselectivecatheter is left in the distal artery

During surgery, the surgeon can palpate thecatheter within the vessel and direct the surgical


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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 ofupper gastric sources for bleeding Kovacs and Jensen noted 17.9% of LGI hemorrhage

presentations involved an upper gastrointestinalsource

NG tube is effective in detecting prepylorichemorrhage


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Evaluation

Digital anorectal examination and anoscopy

Rigid proctosigmoidoscopy will allow the

examiner to evacuate the rectum of blood and

clotsExcludes internal hemorrhoids, anorectal solitary

ulcers, neoplasms, and colitis

Colonoscopy and angiography offertherapeutic intervention

Nuclear scanning is purely diagnostic


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Evaluation

subdivide patients into 3 general clinicalcategories

minor and self-limited

major and self-limited

major and ongoing

Major ongoing hemorrhage requires promptintervention with angiography or surgery

Minor, self-limited may undergo colonic lavageand colonoscopy within 24 hours

Major, self-limited need diagnostic tests todetermine if they require prompt therapy or

observation


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Radionuclide imaging

Detects the slowest bleeding rates

0.10.5 mL/min

More sensitive than angiography

Unfortunately cannot reliably localize the site ofhemorrhage

The specificity of small bowel versus largeintestine bleeding does not reliably compare withangiography

Two general techniques

technetium sulfur colloid scans

99mTc pertechnetate-tagged RBCs


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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%


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Colonoscopy

If the patient appears stable with self-limited hemorrhage,colonoscopy is the preferred diagnostic study

Major benefit depends on ability to provide a definitivelocalization of ongoing active bleeding and the potential fortherapy

Many landmarks for colonoscopy may be obscured duringhemorrhage

Once the endoscopist highlights a bleeding source, theregion 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, andlaser therapy

Injection therapy uses topical and intramucosal epinephrine

Mechanical therapy includes endoscopically applied clips


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Angiography

Diagnostic and therapeutic

Acute, major hemorrhage with ongoingbleeding requires emergency angiography

Patients with an early blush during nuclearscintigraphy may benefit from therapeuticangiography

May define a potential source for hemorrhage

in occult and recurrent gastrointestinalhemorrhage

Requires a hemorrhage rate of at least 1mL/min

Yields range from 40% to 78%


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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


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Operative therapy

Few patients currently require surgical treatment

Hemodynamically unresponsive to initial resuscitation

Site of hemorrhage localized, but available therapeuticinterventions fail to control the bleeding

Patient mortality increases with their transfusion requirements Once reaches 67 units and the hemorrhage remains

ongoing, surgical intervention becomes eminent

First objective in surgery focuses on the location of theintraluminal blood with the goal of segmentally isolating thepossible sources of bleeding

if no source appears obvious, may consider intestinalenteroscopy


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Operative therapy

If the source of bleeding cannot be found, and itappears to arise from the colon, the surgeonshould 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 nobleeding persists.


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Algorithm


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