Gastrointestinal Bleeding

Published on 10/02/2015 by admin

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33 Gastrointestinal Bleeding

Sheryl L. Heron, Patricia Baines

Key Points

• Morbidity and mortality from gastrointestinal bleeding increase significantly if aggressive resuscitation is not initiated immediately in the emergency department.^1,²

• Assessment and management of gastrointestinal bleeding depend on the site of the hemorrhage—that is, whether the bleeding is from an upper or lower gastrointestinal tract source.

• Gastroenterology consultation should be obtained immediately to arrange for diagnostic and therapeutic endoscopy or colonoscopy for cases of active bleeding.

• Causes of gastrointestinal bleeding in children vary considerably with age; most cases are benign and self-limited, although Meckel diverticulum, midgut volvulus, and intussusception can result in massive rectal bleeding.

Scope

Demographic risk factors for patients with gastrointestinal (GI) bleeding include older age, male gender, and the use of alcohol, tobacco, aspirin, or nonsteroidal antiinflammatory drugs (NSAIDs).³ Risk for bleeding is significantly higher in elderly patients who have recently started a regimen of NSAIDs or regular-dose aspirin than in long-term users of these agents.⁴ Additional independent risk factors are unmarried status, cardiovascular disease, difficulty performing activities of daily living, use of multiple medications, and use of oral anticoagulants.⁵

Intensive resuscitation in the emergency department (ED) significantly decreases mortality in patients with hematemesis (vomiting blood), hematochezia (red bloody stools), or melena (black tarry stools).² Application of the predictive mnemonic BLEED (ongoing bleeding, low systolic blood pressure, elevated prothrombin time, erratic mental status, unstable comorbid disease) at the initial ED evaluation can predict hospital outcomes in patients with acute upper or lower GI hemorrhage.⁶ Although the incidence of peptic ulcer bleeding has decreased, the decline in incidence has occurred only in patients younger than 70 years,⁷ and mortality from multiorgan failure, cardiopulmonary conditions, or terminal malignancy has remained constant.¹

Lower GI bleeding (LGIB) afflicts 20 to 27 of every 100,000 persons annually in the United States.⁸ The rate of LGIB increases more than 200-fold from the third to the ninth decade of life, with 25% to 35% of all cases occurring in elderly patients. It is one of the common medical emergencies that can become life-threatening in elderly patients.^9,¹⁰ Risk stratification for LGIB by Strate et al. has identified seven predictors of severe bleeding: heart rate higher than 100 beats/min, systolic blood pressure lower than 115 mm Hg, syncope, nontender abdominal examination, gross rectal bleeding, aspirin use, and more than two comorbid conditions. Patients with more than three risk factors have an 84% risk for severe bleeding, defined as transfusion of more than 2 units of red blood cells.¹¹^–¹³

Pediatric GI bleeding is fairly common worldwide; however, the incidence of severe GI bleeding in U.S. children is very low.¹⁴ LGIB is a more common complaint in the practice of general pediatrics, and it accounts for 10% to 15% of referrals to a pediatric gastroenterologist.¹⁵^–¹⁷ In most children, bleeding is not life-threatening and ceases spontaneously, with only supportive care being required.^16,¹⁷ The age of the child guides the clinician toward specific diagnoses.^16,¹⁸

Pathophysiology

Upper Gastrointestinal Bleeding

Upper GI bleeding (UGIB) is defined as bleeding from a source proximal to the ligament of Treitz, which is located at the junction of the duodenum and jejunum. UGIB accounts for three quarters of cases of GI tract hemorrhage, with duodenal and gastric ulcers being the specific sources in more than half of patients with an upper tract cause.

Tips and Tricks

Patients with upper gastrointestinal bleeding should be instructed to avoid nonsteroidal antiinflammatory drugs (NSAIDs).^19,²⁰ Studies have shown that the risk for recurrent bleeding is significantly higher in long-term users of NSAIDs or regular-dose aspirin, especially if patients are elderly. For short-term users of NSAIDs or aspirin, cotreatment with proton pump inhibitors (but not with histamine H₂ blockers) may reduce the risk for bleeding to less than the risk in nonusers.⁴

Hematochezia is generally a symptom of LGIB but may be associated with brisk upper tract hemorrhage. UGIB sources are identified in 11% of patients in whom LGIB was initially suspected.³ Melena most commonly results from bleeding proximal to the jejunum and should be considered a marker of UGIB.

Variceal hemorrhage is the most serious complication of portal hypertension and occurs in one third of patients with esophageal varices.³ It is more common in patients with Child B and C cirrhosis.²¹ The extent of severe bleeding depends on portal pressure, variceal size, and variceal wall thickness.²² Esophageal varices should be suspected in any alcoholic with unexplained anemia or obvious GI bleeding.

One study noted a decline in the frequency of peptic ulcer disease in patients with UGIB and reported that the proportion of bleeding ulcers with a nonvisible vessel is now 20%, which is less than previously reported.²³ Such decline may be related to improved treatment of Helicobacter pylori infection.

In children, the pathophysiology of the bleeding is determined by the specific causes of hemorrhage for each age group.²⁴

Lower Gastrointestinal Bleeding

LGIB refers to bleeding that originates from an intestinal source distal to the ligament of Treitz. The majority of patients with hematochezia bleed from a colonic source. Diverticular disease, angiodysplasia, and neoplasm are the leading causes of LGIB in adults. Anal fissure and hemorrhoids are the most benign causes of LGIB. Approximately 10% of all patients will never have a source identified, and up to 40% of patients with LGIB have more than one potential bleeding source.¹¹

Comorbid illnesses and decreased physiologic reserve make elderly patients more vulnerable to the adverse consequences of acute blood loss and prolonged hospitalization.^10,²⁵ Specifically, hematochezia is more commonly associated with syncope, dyspnea, altered mental status, stroke, falls, fatigue, and acute anemia in older patients. Poor prognostic indicators also include continued bright red rectal bleeding, excessive transfusions, orthostasis, shock, and altered mental status on admission.⁹

Red Flags

Use of nonsteroidal antiinflammatory drugs

Coagulopathies

Long-term alcohol use

Neoplasms

Previous aortic surgery

Recent nosebleeds

Data from Swaim M, Wilson J. GI emergencies: rapid therapeutic responses for older patients. Geriatrics 1999;54:20.

Ulcerative colitis accounts for the majority of cases of massive LGIB in young adults in the second or third decade of life. Diverticulosis and arteriovenous malformation are found in older adults.¹⁵

The independent risk factors listed earlier are useful prognostic indicators, and outcomes are poorer in patients with either upper or lower tract bleeding.⁵ Specifically, use of over-the-counter NSAIDs may represent an important cause of peptic ulcer disease and ulcer-related hemorrhage in those with UGIB.^4,²⁶

Although most causes of LGIB in children are self-limited and benign, it is imperative to consider Meckel diverticulum, midgut volvulus, and intussusception in appropriate age groups.¹⁵

Clinical Presentation

Patients with GI bleeding can be rapidly assessed by their reported volume of blood loss and initial hemodynamic status. Massive hemorrhage is associated with signs or symptoms of hemodynamic instability, including tachycardia (heart rate greater than 100 to 120 beats/min), systolic blood pressure less than 90 to 100 mm Hg, symptomatic orthostasis, syncope, ongoing bright red or maroon hematemesis, transfusion requirements in the first 24 hours, and inability to stabilize the patient.²⁷

Vital signs and postural changes should be assessed in patients who appear sufficiently stable. An increase of 20 beats/min or more in pulse or a decrease of 20 mm Hg in systolic blood pressure between the supine and upright positions indicates loss of more than 20% of blood volume in normal adult patients.⁹ Tachycardia, low blood pressure, reduced urine output, and conjunctival pallor in patients with GI bleeding are signs that mandate immediate volume replacement. Hypovolemic shock implies at least a 40% loss of blood volume. Note that abnormalities in vital signs, especially postural vital sign, are unreliable in pediatric and elderly patients.

The history should focus on the quantity, frequency, and duration of bleeding (differentiating between melena and hematochezia) to characterize the nature of the GI bleeding. Comorbid status, including other GI disorders, anticoagulant use, syncope, weight loss, alcohol intake, and cardiovascular disease, should be assessed.

In addition to continuous monitoring of vital signs, physical examination should include assessment of mental status, skin (for jaundice or pallor), and pulmonary and cardiovascular compromise (especially in the elderly because of ischemia from blood loss), as well as a thorough abdominal examination for distension, tenderness, or masses. Digital rectal examination and testing of stool for gross or occult blood should be performed in patients with suspected GI bleeding.

Complaints associated with LGIB include hematochezia or melena, although patients may have additional findings, such as anemia, light-headedness, hypovolemia, weakness, malaise, chest pain, and dyspnea. It is important to note that patients with LGIB may be asymptomatic and have complaints seemingly unrelated to intestinal bleeding (e.g., fatigue, weight loss); dramatic findings consisting of massive rectal bleeding in acutely ill and unstable patients are less common.²⁸

Delayed black tarry stools may occur from a source of bleeding in the small bowel or ascending colon and may not be noted by the patient until several days after the bleeding has stopped.²⁹

A thorough history and complete physical examination are important for evaluation of a child with GI bleeding. Bright red blood that coats but is not mixed with stool suggests an anorectal source. Hematochezia indicates bleeding from the distal part of the small bowel or proximal part of the colon. Bloody diarrhea usually suggests colonic bleeding. Currant-jelly stools are indicative of the vascular congestion and hyperemia seen with intussusception.

Food allergy may lead to GI bleeding from food-induced colitis and could result in dehydration in infants younger than 3 months.¹⁷ Anal fissures are common in infants and produce red streaks or spots of blood in the diaper.¹⁵ Other causes of dark stool are iron, charcoal, flavored gelatin, red fruits, bismuth, and food dyes. Maternal blood swallowed by neonates during delivery may be diagnosed with the Apt test.¹⁷