A. Introduction. Gastrointestinal (GI) bleeding is both a common and a serious problem in the United States.
a. Classification. GI bleeding is traditionally classified as “upper” or “lower,” depending on whether the bleed originates above or below the ligament of Treitz, respectively.
i. Hematemesis is vomitus which contains blood. Often blood is quickly degraded by stomach acid, causing it to look like “coffee grounds.”
ii. Hematochezia is red or maroon-colored blood in the stool. Hematochezia can occur with both lower GI bleeds and rapidly bleeding upper GI bleeds.
In about 10% of patients with hematochezia, the source of bleeding is the upper GI tract.
iii. Melena is black, tarry stool that represents digested blood. Melena usually indicates an upper GI bleed because the blood has been digested to hematin by gastric acid, but small bowel and right-sided colonic hemorrhages may also produce melena. Melena has three characteristics that help to distinguish it from other causes of dark stool: it is dark black, it has a characteristic odor (patients say it smells far worse than normal stool), and it has a consistency that is loose and tarry (or oily). It only takes 50 mL of GI blood loss per day to cause melena.
Bismuth subsalicylate, iron, spinach, and charcoal can produce black stools. However, these substances are not associated with a positive stool guaiac. Additionally, modern stool testing (fecal immunochemical testing [FIT]) only detects lower GI blood loss and rapid upper GI bleeding.
B. Causes of Gastrointestinal Bleeding
MNEMONIC: Gastrointestinal Bleeding—Upper Gastrointestinal Sources (“GUM BLEEDING”)
Gastritis (erosions secondary to nonsteroidal antiinflammatory drugs [NSAIDs], alcohol, or stress)
Ulcers (often caused by Helicobacter pylori or NSAIDs)
Mallory-Weiss tear (often secondary to excessive vomiting)
Biliary (hemobilia, usually secondary to trauma or recent hepatobiliary procedure)
Large varices (a source of catastrophic bleeding seen in patients with portal hypertension)
Esophagitis or Esophageal ulcer
Enteroaortic fistula (usually seen in patients with aortic grafts, typically years after the original surgery)
Duodenitis or Dieulafoy’s lesion (an ectatic artery in the stomach)
Inflammatory bowel disease (upper tract Crohn’s disease)
Neovascularization (arteriovenous malformation), usually seen in older adults; more commonly causes lower GI bleeding
b. Lower GI source. Use the following mnemonic to remember the causes of lower GI tract bleeding—you may need a “DRAIN” to collect the blood.
MNEMONIC: Gastrointestinal Bleeding—Lower Gastrointestinal Sources (“DRAIN”)
Arteriovenous malformation (angiodysplasia)
Ischemia, Inflammation, or Infection
i. Diverticulosis is the most common cause of lower GI bleeding. The disorder is painless and is almost never a cause of chronic blood loss. Because bleeding is an unusual finding in diverticulitis, painful bleeding suggests a nondiverticular source.
ii. Radiation proctitis can occur at any time following radiation therapy. It commonly occurs after radiation of the prostate (men) or cervix/uterus (women).
iii. Arteriovenous malformations (angiodysplasia) occur primarily in older adults and may cause both acute and chronic blood loss.
iv. Ischemia. In widespread mesenteric ischemia, for example, the patient often experiences pain out of proportion to the examination. However, ischemic colitis in the “watershed” area of the left colon typically presents with left lower quadrant pain and bleeding. In many instances, it can be painless.
v. Inflammatory bowel disease is usually accompanied by diarrhea and rarely causes massive bleeding.
vi. Infectious colitis is also usually accompanied by diarrhea.
vii. Neoplasms (benign or malignant) usually cause chronic, rather than acute, blood loss.
C. Approach to the Patient
a. Patient history. The history is helpful for distinguishing between an upper and lower source of bleeding but is poor for determining the exact cause of the bleeding. It is important to inquire about the following:
i. Number of episodes
ii. Most recent episode
iii. Use of NSAIDs, aspirin, or other antiplatelet agents
iv. Use of anticoagulants
v. Use of proton pump inhibitors (regular use makes an upper GI source less likely)
vi. Cirrhosis (which increases the likelihood of portal hypertensive causes of bleeding, such as varices)
vii. Alcohol abuse
viii. Vomiting before hematemesis
ix. Presence and location of abdominal pain
x. Prior aortic surgery
xi. Previous history of GI bleeding, if any
b. Physical examination
i. Vital signs. Check orthostatics—if your patient “tilts” (i.e., moving from a supine position to an upright position causes his or her pulse to increase by more than 20 beats/min or systolic blood pressure to decrease by more than 10 mm Hg), then intravascular volume is 10%–20% below normal. Patients taking β-blockers might have a “normal” pulse rate, despite a large volume loss. Additionally, older adult or diabetic patients may have orthostasis even without bleeding.
ii. HEENT. Check for scleral icterus, which may indicate liver disease with associated varices. Rule out epistaxis and oral lesions as a source of upper GI tract bleeding.
iii. Lungs and heart. Check for evidence of left ventricular dysfunction, which can increase the risk for volume overload with fluid administration. Also look for a characteristic systolic ejection murmur of aortic stenosis, which increases the risk for arteriovenous malformations (Heyde’s syndrome).
iv. Abdomen. Given the cathartic nature of blood, the absence of bowel sounds may suggest an intraabdominal catastrophe. Look carefully for rigidity, involuntary guarding, and rebound tenderness, which may suggest peritonitis. Presence of borborygmi (bowel sounds heard without a stethoscope) indicates increased motility from blood in the small bowel (typically suggesting an upper GI source). If the amount of blood being passed from above or below is not consistent with the patient’s clinical picture, consider intraperitoneal bleeding.
v. Rectum. Palpate for rectal masses. A stool guaiac can be performed if the stools are not clearly bloody, but this highly sensitive test is not specific for acute blood loss. Moreover, FIT testing is insensitive for upper GI bleeding.
vi. Neurologic examination. Check for asterixis (evidence of liver disease).
vii. Skin. Look for signs of liver disease, such as jaundice, spider angiomas, and palmar erythema.
c. Diagnostic tests. Important initial tests to consider include:
i. Blood typing and cross-matching
ii. Complete blood count (CBC) with platelets (though the CBC may be normal early in the course)
iii. Electrolyte panel
iv. Blood urea nitrogen (BUN) and creatinine levels (BUN can be elevated in upper GI bleeding independent of volume loss)
v. Liver tests
vi. Prothrombin time (PT) and partial thromboplastin time (PTT)
viii. Electrocardiogram (EKG)
d. General guidelines for the management of a patient with GI bleeding. In a patient with GI bleeding, do not delay management because you have not figured out the cause of the bleeding! GI bleeding is a situation in which the initial management is similar, regardless of the exact cause.
i. Always begin by evaluating the ABCs (airway, breathing, circulation) and assessing the patient’s clinical status.
ii. Begin fluid replacement. Intravenous access should be obtained immediately, preferably with two large-bore (18-gauge or larger) intravenous lines.
iii. Insert a nasogastric tube (NGT) if there is any possibility an upper GI bleed exists. Remember that some patients with upper GI bleeding will have hematochezia. Bolus with at least 500 mL of water, then withdraw the fluid through the NGT; keep a tab of how much water it takes for the aspirate to become almost clear.
1. The NGT aspirate may be negative, even in the presence of upper GI bleeding, if:
a. The source of the bleeding is below the end of the nasogastric tube (e.g., if the nasogastric tube ends in the stomach, bleeding from a duodenal ulcer may not be apparent in the aspirate).
b. The bleeding is transient.
c. Nasogastric lavage that does not contain bile is not adequate to assess duodenal bleeding.
2. The tube should be kept in place if there is active bleeding or signs of small bowel obstruction. Otherwise, the tube can be removed after the aspirate has been assessed.
iv. Hold antihypertensive or diuretic therapy. In addition, the patient should receive nothing by mouth.
v. Decide whether to admit the patient to the intensive care unit (ICU).
1. If your patient needs to take a trip to the ICU, he or she will need a “VISA.” Patients generally require admission if any of the following criteria are met:
MNEMONIC: Criteria for Admittance to ICU with a Gastrointestinal Bleed (“VISA”)
Variceal bleeding (suspected or confirmed)
Instability of vital signs
Serious comorbid conditions (e.g., coronary artery disease, chronic obstructive pulmonary disease [COPD])
Active GI bleeding or Advanced age (which is a negative prognostic indicator)
2. All patients admitted to the ICU should be seen by a gastroenterologist immediately. However, remember that resuscitation should not be delayed while awaiting a consult with a gastroenterologist.
No diagnostic testing (endoscopic or radiologic imaging) can be performed without significant risk until the patient is adequately volume-resuscitated.
a. Older adult patients or those with coronary artery disease are often transfused to keep their hematocrit greater than 30% (or hemoglobin greater than 10 mg/dL), although data suggest that aggressive transfusion is not associated with better outcomes. At least 2 units of typed and cross-matched packed red blood cells (pRBCs) should be kept in the blood bank at all times for these patients, regardless.
b. In a patient with active bleeding, consider a platelet transfusion if the patient’s platelet count is less than 50,000/μL, or if the patient is on antiplatelet agents. Fresh-frozen plasma should be used if the patient’s international normalized ratio (INR) is greater than 1.5.
2. Intravenous proton pump inhibitors should be administered, especially if an upper GI source of bleeding is suspected.
3. Octreotide can be considered in patients with upper GI bleeding from any cause but especially in those with a portal hypertensive cause (to reduce splanchnic blood flow).
4. Vitamin K should be administered if the patient’s PT or PTT is abnormal.
Transfusion of one unit of blood should raise the patient’s hemoglobin level by approximately 1 g/dL. Failure to rise may indicate hemolysis or ongoing blood loss.
vii. Ancillary tests
1. After resuscitation, patients with evidence of ongoing upper GI bleeding should undergo upper endoscopy within a few hours. This “urgent” endoscopy will not only help assess the source of bleeding but also allow for an attempt to achieve hemostasis through endoscopic interventions. In patients with no clear ongoing bleeding, endoscopy should typically be performed within 12–24 hours. Keep in mind that early endoscopy is not necessarily better than late endoscopy; ensuring the patient is adequately resuscitated and stable is key.
2. In the setting of suspected lower GI bleeding that stops, a colonoscopy is typically indicated. Stable patients can often be prepped for colonoscopy the night of admission after consultation with the gastroenterologist such that colonoscopy can be performed the following morning. Unstable patients can be “rapid prepped” (with a nasogastric tube) for emergent colonoscopy.
3. In patients with ongoing significant GI bleeding without an obvious source, or in patients with presumed lower GI bleeding who are not amenable to endoscope evaluation, a technetium-99m (99mTc)- labeled red blood cell scan can be performed. This scan may help identify and localize a small bowel or colonic source of bleeding. The amount of bleeding must be at least 0.05–0.1 mL/min for this test to be useful (compared with 0.5–1.0 mL/min with angiography).
4. A visceral angiogram is typically indicated when a source has been identified on a labeled red blood cell scan. Angiography can be done for both diagnostic and therapeutic (embolization) purposes.
5. Capsule endoscopy. Capsule endoscopy is performed primarily to assess bleeding from the small bowel. This is typically performed in the setting of chronic GI bleeding with negative colonoscopy and upper endoscopy. However, it can be done in semi-acute bleeding suggestive of a small bowel source. The capsule endoscope is a diagnostic modality; it does not provide therapeutic options. Capsule endoscopy should be preceded by a “patency capsule” in patients with suspected small bowel neoplasia or inflammatory bowel disease to ensure that the capsule will not become lodged in the small bowel.
Suggested Further Readings
Clair DG, Beach JM. Mesenteric ischemia. N Engl J Med 2016;374:959–68.Find this resource:
Gralnek IM, Neeman Z, Strate LL. Acute lower gastrointestinal bleeding. N Engl J Med 2017;376:1054–63.Find this resource:
Laine L. Clinical practice. Upper gastrointestinal bleeding due to a peptic ulcer. N Engl J Med 2016;374:2367–76.Find this resource:
Srygley FD, Gerardo CJ, Tran T, Fisher DA. Does this patient have a severe upper gastrointestinal bleed? JAMA 2012;307:1072–9.Find this resource: