Page 5 - Gastrointestinal Bleeding (Xuất huyết tiêu hóa)

CHAPTER 20 Gastrointestinal Bleeding 279

levels. A low MCV and negative fecal occult blood test (FOBT) than 15 seconds, respectively. In a large study from Barcelona,
result raise the possibility of celiac disease. A high MCV (>100 fL) patients with severe UGI bleeding were randomized to receive 20
suggests chronic liver disease or folate or vitamin B 12 deficiency. transfusions either when the hemoglobin level was less than 7 g/
An elevated WBC count may occur in more than half of patients dL or when the hemoglobin level was less than 9 g/dL. The
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with UGI bleeding and has been associated with greater severity former (“restrictive”) transfusion strategy was associated with a
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of bleeding. A low platelet count can contribute to the severity higher survival rate and lower rebleeding rate in patients with
of bleeding and suggests chronic liver disease or a hematologic bleeding owing to peptic ulcer and in those with Child-Pugh class
disorder. In patients with UGI bleeding, the blood urea nitrogen A or B cirrhosis but a lower survival rate and higher rebleeding
level typically increases to a greater extent than the serum creati- rate in those with Child-Pugh class C cirrhosis (see Chapter 92).
nine level because of increased intestinal absorption of urea after Decisions about the timing of transfusion need to be individual-
the breakdown of blood proteins by intestinal bacteria. The pro- ized based on a patient’s clinical status and comorbidities and the
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thrombin time (PT) and INR assess whether a patient has impair- rapidity of blood loss.
ment of the extrinsic coagulation pathway. Values can be elevated An endoscopist should be consulted as soon as possible to
in chronic liver disease or with warfarin. expedite the patient’s assessment and determine the optimal tim-
ing of endoscopy. In hospitals with an LT program, the trans-
Clinical Determination of the Bleeding Site plantation hepatology service should also be notified if the patient
is known to have cirrhosis and is a potential transplant candidate
Presentation with hematemesis, coffee-ground emesis, or NG (see Chapter 97).
lavage with return of a large amount of blood or coffee-ground The patient’s vital signs should be monitored frequently, as
emesis indicates a UGI source of bleeding. A small amount of appropriate to the level of hospitalization. Laboratory-deter-
coffee-ground material or pink-tinged fluid that clears easily may mined hematocrit and hemoglobin values (not fingerstick hema-
represent mucosal trauma from the NG tube rather than active tocrit values, which are less reliable) should be obtained every 4
bleeding from a UGI source. A clear (nonbloody) NG aspirate to 8 hours until the hematocrit and hemoglobin values are stable.
does not necessarily indicate a more distal GI source bleeding, In patients with active bleeding, an indwelling urinary catheter
because at least 16% of patients with actively bleeding UGI should be placed to monitor the patient’s urine output.
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lesions have a clear NG aspirate. The presence of bile in the NG Endotracheal intubation should be considered in patients with
aspirate makes acute UGI bleeding unlikely but can be seen with active ongoing hematemesis or with altered mental status to pre-
an intermittently bleeding UGI source. vent aspiration pneumonia. Patients who are older than 60 years
Melena generally indicates a UGI source but can be seen with of age, have chest pain, or have a history of cardiac disease should
small intestinal or proximal colonic bleeding. Hematochezia gen- be evaluated for myocardial infarction with electrocardiography
erally implies a colonic or anorectal source of bleeding unless the and serial troponin measurements. A chest x-ray should also be
patient is hypotensive, which could indicate a severe, brisk UGI considered.
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bleed with rapid transit of blood through the GI tract. Maroon-
colored stool can be seen with an actively bleeding UGI source or Initial Medical Therapy
a small intestinal or proximal colonic source.
Administration of a PPI is useful for reducing rebleeding rates in
Hospitalization patients with PUD (see later). Starting a PPI in the emergency
department or ICU before endoscopy is performed in patients
Patients with severe GI bleeding require hospitalization, whereas with severe UGI bleeding has become a common practice but
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those who present with only mild acute bleeding (self-limited is still controversial. Several clinical studies and meta-analyses
hematochezia or infrequent melena) and who are hemody- have shown that infusion of a PPI in a high dose before endos-
namically stable (not suspected to be volume depleted), have copy accelerates the resolution of endoscopic stigmata of recent
normal blood test results, and can be relied on to return to the hemorrhage (SRH) in ulcers (see later) and reduces the need for
hospital if symptoms recur, may be candidates for semiurgent endoscopic therapy but does not result in improvement in clinical
outpatient endoscopy rather than direct admission to the hos- major outcomes. 16-19 Patients with a strong suspicion of portal
pital. 10,11 Patients should be hospitalized in an ICU if they have hypertension and variceal bleeding should be started empiri-
large amounts of red blood in the NG tube or per rectum, have cally on IV octreotide (bolus followed by infusion [see later and
unstable vital signs, or have had severe acute blood loss that may Chapter 92]), which can reduce the risk of rebleeding to a rate
exacerbate other underlying medical conditions. Patients who similar to that following endoscopic therapy (Fig. 20.2; also see
have had an acute GI bleed but are hemodynamically stable Fig. 20.1). 20,21
can be admitted to a monitored bed (step-down unit) or stan-
dard hospital bed, depending on their clinical condition. Urgent Endoscopy
endoscopy performed in the emergency department in patients
with a suspected UGI bleed can help determine optimal hospital GI endoscopy will identify the bleeding site and permit thera-
placement. 12,13 peutic hemostasis in most patients with GI bleeding. There
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is a controversy about the timing of endoscopy for patients
Resuscitation with severe UGI bleeding. The consensus is that for patients
with severe comorbidities (such as American Society of
Resuscitation efforts should be initiated at the same time as initial Anesthesiologists Physical Status class 3 to 4) (see Chapter 42),
assessment in the emergency department and continue during the the optimal period for performing EGD associated with the least
patient’s hospitalization. At least 1 large-bore (14- or 16-gauge) mortality is after the patient has been hemodynamically resus-
catheter should be placed intravenously, and 2 should be placed citated but within 12 to 20 hours of presentation. Emergency
when the patient has ongoing bleeding. Normal saline is infused endoscopy before or after this interval is associated with higher
as fast as needed to keep the patient’s systolic blood pressure mortality rates. For hemodynamically stable patients with less
higher than 100 mm Hg and pulse lower than 100/min. Patients severe comorbidity (American Society of Anesthesiologists class
should be transfused with packed RBCs, platelets, and fresh fro- 1 to 2), EGD within 24 hours is associated with lower mortal-
zen plasma as necessary to keep the hemoglobin level greater ity. Endoscopy should be done only when it is safe to do so
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than 7 g/dL, platelet count higher than 50,000/mm , and PT less and when the information obtained from the procedure will