Page 2 - Gastrointestinal Bleeding (Xuất huyết tiêu hóa)

P. 2

20 Gastrointestinal Bleeding

Thomas J. Savides, Dennis M. Jensen

CHAPTER OUTLINE blood, which suggests recent or ongoing bleeding, and dark mate-
rial (coffee-ground emesis), which suggests bleeding that stopped
INITIAL ASSESSMENT AND MANAGEMENT OF ACUTE some time ago. Melena is defined as black tarry stool and results
from degradation of blood to hematin or other hemochromes by
GASTROINTESTINAL BLEEDING ��276 intestinal bacteria. Melena can signify bleeding that originates
History ��276 from a UGI, small bowel, or proximal colonic source and gen-
Physical Examination��276 erally occurs when 50 to 100 mL or more of blood is delivered
Laboratory Studies ��278 into the GI tract (usually the upper tract), with passage of charac-
Clinical Determination of the Bleeding Site ��279 teristic stool occurring several hours after the bleeding event.
2,3
Hospitalization ��279 Hematochezia refers to bright red blood per rectum and suggests
Resuscitation ��279 colonic or anorectal bleeding or active UGI or small bowel bleed-
Initial Medical Therapy ��279 ing. Occult GI bleeding refers to subacute bleeding that is not clini-
Endoscopy ��279 cally visible. Obscure GI bleeding is bleeding from a site that is not
Endoscopic Hemostasis ��282 apparent after routine endoscopic evaluation with EGD (upper
endoscopy), and colonoscopy, and possibly push enteroscopy. An
Imaging ��283 algorithm for the initial management of severe acute UGI bleed-
Surgery ��283 ing is shown in Fig. 20.1.
UPPER GASTROINTESTINAL BLEEDING ��283
Epidemiology ��283 INITIAL ASSESSMENT AND MANAGEMENT OF ACUTE
Risk Factors and Risk Stratification ��283 GASTROINTESTINAL BLEEDING
Upper Endoscopic Technique ��284
Peptic Ulcer ��284 History
Other Nonvariceal Causes ��294 Initial assessment of the patient with acute GI bleeding includes
LOWER GASTROINTESTINAL BLEEDING ��299 taking a medical history, obtaining vital signs, performing a phys-
Risk Factors and Risk Stratification ��299 ical examination, including a rectal examination, and NG lavage.
Mortality ��300 Patients should be questioned about risk factors such as medica-
Diagnostic and Therapeutic Approach ��300 tion that may cause ulcers or bleeding, prior GI surgeries, and
Causes and Management ��301 historical features that help identify diagnostic possibilities for
OBSCURE OVERT GASTROINTESTINAL BLEEDING ��306 the bleeding source (Table 20.1).
Causes ��306 Physical Examination
Diagnostic Tests ��309
OBSCURE OCCULT GASTROINTESTINAL BLEEDING AND On initial evaluation, physical examination should focus on the
IRON DEFICIENCY ANEMIA ��311 patient’s vital signs, with attention to signs of hypovolemia such
as hypotension, tachycardia, and orthostasis. The abdomen should
Fecal Occult Blood ��311 be examined for surgical scars, tenderness, and masses. Signs of
Iron Deficiency Anemia ��311 chronic liver disease include spider telangiectasias, palmar ery-
thema, gynecomastia, ascites, splenomegaly, caput medusae, and
Dupuytren contracture. The skin, lips, and buccal mucosa should
be examined for telangiectasias, which are suggestive of HHT, or
The annual rate of hospitalization for any type of GI hemorrhage Osler-Weber-Rendu disease. Subungual telangiectasias and char-
in the US is estimated to be 350 hospital admissions/100,000 acteristic changes of the skin of the fingers may indicate sclero-
1
population, with more than 1,000,000 hospitalizations each year. derma (systemic sclerosis), which is associated with GAVE or UGI
Approximately 50% of admissions for GI bleeding are for UGI telangiectasias. Pigmented lip lesions may suggest Peutz-Jeghers
bleeding (from the esophagus, stomach, and duodenum), 40% are syndrome. Purpuric skin lesions may suggest Henoch-Schönlein
for LGI bleeding (from the colon and anorectum), and 10% are purpura. Acanthosis nigricans may suggest underlying malig-
for obscure bleeding (from the small intestine). nancy, especially gastric cancer. The patient’s feces should be
Severe GI bleeding is defined as documented GI bleeding observed to identify melena or maroon and red stool; however, the
(hematemesis, melena, hematochezia, or positive NG lavage) subjective description of stool color varies greatly among patients
accompanied by shock or orthostatic hypotension, a decrease in and physicians. 4
the hematocrit value by at least 6% (or a decrease in the hemo- NG or orogastric tube placement to aspirate and visually char-
globin level of at least 2 g/dL), or transfusion of at least 2 units acterize gastric contents can be useful for determining the pres-
of packed red blood cells (RBCs). Most patients with severe GI ence or absence of large amounts of red blood, coffee-ground
bleeding are admitted to the hospital for resuscitation and treat- material, or nonbloody fluid; it is particularly useful in patients
ment. Overt bleeding implies visible signs of blood loss from the with melena in the absence of hematemesis. Occult blood testing
GI tract. Hematemesis is defined as vomiting of blood, which is of an NG tube aspirate is not useful, however, because trauma
indicative of bleeding from the nasopharynx, esophagus, stom- from the NG tube may induce sufficient, although scant, bleeding
ach, or duodenum. Hematemesis includes vomiting of bright red to cause a false-positive result. Patients who have coffee-ground
276

1 2 3 4 5 6 7