Page 11 - Gastrointestinal Bleeding (Xuất huyết tiêu hóa)

CHAPTER 20 Gastrointestinal Bleeding 285

No diagnosis or The lifetime risk of peptic ulcer disease from Hp infection ranges
>1 type of lesion from 3% in the US to 25% in Japan (see Chapter 52). 20
NSAIDs are the most widely used medication in the USA,
No diagnosis Ulcer 11% Other with 11% of the adult population using NSAIDs on a daily
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or >1 type basis. Many are bought over the counter and without a doctor’s
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of lesion prescription. NSAIDs, including aspirin, predominantly cause
59% 33% ulceration by inhibiting COX-mediated prostaglandin synthesis
and thereby impairing mucosal protection, rather than by causing
7% 39% direct topical injury. Gastroduodenal ulcers are found at endos-
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22% 17% copy in 15% to 45% of patients who take NSAIDs regularly. 90,91
12% Gastric ulcers are approximately 4 times as common as duodenal
ulcers in patients who take NSAIDs. In a large study of patients
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Gastroesophageal with UGI hemorrhage and NSAID-associated ulcers, however,
Other varices gastric and duodenal ulcers occurred with equal frequencies (see
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1983-1992 2000-2008 Chapter 53).
(n = 945) (n = 300)
Fig. 20.6 Frequencies of major causes of severe UGI bleeding during 2 Histopathology
time periods in patients seen at UCLA CURE. (All differences between In a landmark study by Swain and colleagues, the pathologic
the 2 time periods are statistically significant; P < 0.05.) Note that in the examination of 27 surgically resected bleeding gastric ulcers with
more recent period, the overall number of cases of severe UGI bleeding endoscopically visible vessels revealed an underlying artery in
and the percentage of cases caused by peptic ulcer have declined. 96% of specimens. Approximately 50% of the vessels protruded
33
CURE, Center for Ulcer Research and Education; UCLA, University of above the surface of the ulcer, whereas the other 50% had an
California, Los Angeles
adherent clot in continuity with a breach in the artery wall. The
bleeding arteries had a mean diameter of 0.7 mm, with a range of

BOX 20�1 Factors Predictive of a Poor Prognosis After 0.1 to 1.18 mm.
Hemorrhage From Peptic Ulcer
Endoscopic Risk Stratification
Age >60 years In the United Kingdom, Asia, and some other countries, the
Bleeding onset in hospital Forrest classification is used to categorize findings during endo-
Severe comorbid medical illness scopic evaluation of bleeding peptic ulcers as follows: active spurt-
Shock or orthostatic hypotension ing bleeding (Forrest IA), oozing of blood (Forrest IB), pigmented
Fresh blood in NG tube protuberance or nonbleeding visible vessel (NBVV [Forrest IIA]),
Coagulopathy adherent clot (Forrest IIB), flat pigmented spot (Forrest IIC), and
Multiple transfusions required clean-based ulcer (Forrest III). Descriptive terms are used in the
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Higher lesser curve gastric ulcer (adjacent to left gastric artery) USA and other countries. Overall interobserver agreement among
Posterior duodenal bulb ulcer (adjacent to gastroduodenal artery) experts for classifying these SRH to the Forrest classification is
Endoscopic finding of arterial bleeding or visible vessel only fair to moderate, with poor agreement for NBVVs. 94,95
Residual arterial blood flow after endoscopic treatment Endoscopic SRH from an ulcer is shown in Fig. 20.7, and the
risk of rebleeding associated with each stigma is shown in Fig.
20.8. Patients at high risk of rebleeding without treatment are
an increase in the rate in the subgroup of older patients taking those with active arterial bleeding (90%), an NBVV (50%), or
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NSAIDs (Fig. 20.6). The mortality rate associated with peptic an adherent clot (33%). 96,97 These patients benefit from endo-
ulcer bleeding is 5% to 10%. 61,62 The costs of hospitalization for scopic hemostasis (see later). An endoscopically identified NBVV
peptic ulcer bleeding are estimated to be more than $2 billion per that has a translucent (pearl or whitish) color has a higher risk
year in the US (see Chapter 53). Clinical and endoscopic factors of rebleeding than a darkly colored pigmented protuberance
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in patients with peptic ulcer bleeding associated with increased (clot), because the translucent stigma likely represents the arte-
morbidity and mortality are shown in Box 20.1. rial wall. 98,99 A multivariate analysis of predictors of persistent
or recurrent bleeding in patients with nonvariceal UGI bleed-
Pathogenesis ing is shown in Table 20.4. Patients with major SRH (spurting,
NBVV, or adherent clot) benefit most from endoscopic hemo-
Peptic ulcers are most commonly caused by a decrease in mucosal stasis, whereas those with a clean ulcer base do not. Patients with
defense mechanisms attributable to aspirin or other NSAIDs, Hp oozing bleeding or flat spots and no other stigma (e.g., a clot or
infection, or both (see Chapters 52 and 53). 85,86 In one large mul- NBVV) may benefit from endoscopic hemostasis but not from
ticenter study of patients with severe peptic ulcer bleeding, 57% infusion of high-dose PPI (see later).
of those with bleeding from a gastric ulcer (n = 2057) took aspirin The risk of rebleeding from a peptic ulcer decreases signifi-
or another NSAID, and 45% were infected with Hp, whereas cantly 72 hours after the initial episode of bleeding. This conclu-
53% of those with a bleeding duodenal ulcer (n = 2033) took sion is based on studies in which only active bleeding was treated
aspirin or another NSAID, or both, and 50% were infected with endoscopically, all other stigmata were observed, and all patients
Hp. Of the patients with a bleeding peptic ulcer in this study, were treated with an IV H2RA and cessation of aspirin and other
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10% had no obvious cause for the ulcer (Hp-negative, no aspirin NSAIDs. 98-102 Natural history studies of untreated NBVVs have
or other NSAID use, no cancer, no gastrinoma). found that these lesions resolve over 4 days, and adherent clots
The prevalence of Hp infection is more than 80% of the pop- tend to resolve over 2 days. 103
ulation in many developing countries and 20% to 50% in indus-
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trialized countries. Hp gastritis most commonly involves the Doppler Endoscopic Probe
antrum and predisposes patients to duodenal ulcers, whereas gas- Portable Doppler endoscopic probes (DEP) can be passed through
tric body-predominant gastritis is associated with gastric ulcers. the working channel of an endoscope and applied to an ulcer to