Date post: | 14-Apr-2018 |
Category: |
Documents |
Upload: | mien-buntara |
View: | 221 times |
Download: | 0 times |
of 23
7/29/2019 Lower Gi Bleed 4611
1/23
LOWER GI BLEEDING
4/6/11
7/29/2019 Lower Gi Bleed 4611
2/23
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
7/29/2019 Lower Gi Bleed 4611
3/23
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)
7/29/2019 Lower Gi Bleed 4611
4/23
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
7/29/2019 Lower Gi Bleed 4611
5/23
Etiology
Diverticula
Angiodysplasia
Ischemic colitis
Inflammatory bowel disease
Intestinal tumors or malignancies
NSAID-related nonspecific colitis
Meckels diverticulum
Anorectal diseases
7/29/2019 Lower Gi Bleed 4611
6/23
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
7/29/2019 Lower Gi Bleed 4611
7/23
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
7/29/2019 Lower Gi Bleed 4611
8/23
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
7/29/2019 Lower Gi Bleed 4611
9/23
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
7/29/2019 Lower Gi Bleed 4611
10/23
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
7/29/2019 Lower Gi Bleed 4611
11/23
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
7/29/2019 Lower Gi Bleed 4611
12/23
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
7/29/2019 Lower Gi Bleed 4611
13/23
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
7/29/2019 Lower Gi Bleed 4611
14/23
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
7/29/2019 Lower Gi Bleed 4611
15/23
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
7/29/2019 Lower Gi Bleed 4611
16/23
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%
7/29/2019 Lower Gi Bleed 4611
17/23
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
7/29/2019 Lower Gi Bleed 4611
18/23
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%
7/29/2019 Lower Gi Bleed 4611
19/23
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
7/29/2019 Lower Gi Bleed 4611
20/23
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
7/29/2019 Lower Gi Bleed 4611
21/23
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.
7/29/2019 Lower Gi Bleed 4611
22/23
Algorithm
7/29/2019 Lower Gi Bleed 4611
23/23