Page 25 - Gastrointestinal Bleeding (Xuất huyết tiêu hóa)

CHAPTER 20 Gastrointestinal Bleeding 299

LOWER GASTROINTESTINAL BLEEDING Administration Hospital, 64% of patients with severe hemato-
chezia required a therapeutic intervention to control continued 20
27
LGI bleeding generally signifies bleeding from the colon or ano- bleeding or rebleeding : 39% underwent endoscopic hemostasis,
rectum. The annual incidence of LGI bleeding is approximately 1% underwent angiographic embolization, and 24% underwent
20 cases/100,000 population, with an increased risk in older surgery.
adults. 235 The rate of hospitalization for LGI bleeding is lower
than that for UGI bleeding. Most patients are older than 70 years Risk Factors and Risk Stratification
of age. Patients usually present with painless hematochezia and a
decrease in the hematocrit value but without orthostasis. If ortho- Nonselective NSAIDs increase the risk of LGI bleeding com-
stasis is associated with hematochezia, a briskly bleeding UGI pared with placebo. 241,242 The main risk factors for NSAID-
source should be excluded (see earlier); severe painless hema- associated LGI bleeding appear to be an age of 65 years or older
tochezia results from a foregut source in approximately 15% of and prior history of LGI bleeding. 243 Whether use of long-term
noncirrhotic patients. 236 The sites of origin within the GI tract of selective COX-2 inhibitors is associated with a lower risk of LGI
severe hematochezia at UCLA CURE are shown in Fig. 20.18. bleeding than nonselective NSAIDs is uncertain.
Patients with LGI bleeding should initially be resuscitated Table 20.9 shows clinical factors that are predictive of severe
medically. After they have been stabilized, they should generally LGI bleeding (defined as continued bleeding within the first 24
27
undergo urgent colonoscopy after a PEG purge. For patients with hours of hospitalization, with a transfusion requirement of at least
cirrhosis, a recent history of melena or hematemesis, or a history
of PUD, “panendoscopy” (upper and lower endoscopy) is recom-
mended first. 236,237 In early reports, urgent colonoscopy resulted TABLE 20.8 Colonic Causes of Severe Hematochezia (%)
in a diagnosis in approximately 70% of cases; 238,239 however, in
subsequent reports, the combination of urgent colonoscopy and, if Study
necessary, push enteroscopy, anoscopy, and capsule endoscopy has Reference Reference UCLA CURE*
resulted in a diagnosis in 95% of cases (see Fig. 20.4). 236,237 Lesion 239 240 (2018)
The most common causes of LGI bleeding are shown in Table Diverticulosis 30 33 33
20.8. Diverticulosis is the most common cause of acute LGI
bleeding and occurs in approximately 30% of cases. Colonic Colon cancer or polyps 18 21 5.2
2
polyps or cancer, colitis, and anorectal disorders each account for Colitis 17 17 N/A
approximately 20% of cases. 240 Ischemic colitis N/A 7 11.9
In most cases, acute LGI bleeding will stop spontaneously,
thereby allowing nonurgent diagnosis and treatment. For patients IBD N/A 4 3.6
with ongoing or recurrent hematochezia, urgent diagnosis and Noninfectious colitis N/A 5 2.7
treatment are required to control the bleeding. In a large series of Infectious colitis N/A 1 1.2
patients at the UCLA Medical Center and Wadsworth Veterans Angioectasia 7 6 5.0

Postpolypectomy ulcer 6 N/A 7.8
Small intestine Rectal ulcer N/A 1 8.4
5% (n = 30) Hemorrhoids N/A 20 10.3
No source identified Anorectal source (other) 4 3 1.8 †
3% (n = 18) Colon Radiation colitis 0 0.5 2.2
75% (n = 486)
Colon anastomotic ulcer N/A N/A 2.1
UGI tract Other 8 3 4.1
17% (n = 113) Unknown 16 0 0
Fig. 20.18 Frequencies of sources of severe hematochezia in patients
*N = 823.
seen at UCLA CURE. Note that in most cases (75%), severe hemato- † Anal fissure following rubber band ligation, ulcer, rectal cancer, or other
chezia is from the colon, 17% is from a UGI (esophagus, stomach, or anorectal lesion.
duodenum) source, and 5% is from a small intestinal source. CURE, CURE, Center for Ulcer Research and Education; UCLA, University of
Center for Ulcer Research and Education; UCLA, University of Califor- California, Los Angeles; N/A, not available.
nia, Los Angeles.

TABLE 20.9 Clinical Prediction Score and Outcomes of Severe Acute LGI Bleeding
Mean Number of Units
Total Risk Frequency Risk of Severe Need for Mortality Hospital Transfused (Packed
Points* (%) Bleeding (%) Surgery (%) Rate (%) Days Red Blood Cells)
0 6 6 0 0 2.8 0
1-3 75 43 1.5 2.9 3.1 1
≥4 19 79 7.7 9.6 4.6 3

*Risk factors (1 point each): aspirin use; more than 2 comorbid illnesses; heart rate ≥100/min; nontender abdominal examination; rectal bleeding within the
first 4 hr of evaluation; syncope; systolic blood pressure ≤115 mm Hg.
Severe LGI bleeding is defined as continued bleeding within the first 24 hr of hospitalization (transfusion of 2 or more units of packed red blood cells and/
or hematocrit value drop of 20% or more) and/or recurrent bleeding after 24 hr of stability (need for additional transfusions, further hematocrit value
decrease of 20% or more, or readmission to the hospital for LGI bleeding within 1 week of discharge).
Data from Strate LL, Saltzman JR, Ookubo R, et al. Validation of a clinical prediction rule for severe acute lower intestinal bleeding. Am J Gastroenterol 2005;
100:1821–7.