Gastrointestinal Bleeding¶
Chapter 51 | Gastrointestinal Bleeding
KEY CLINICAL POINTS¶
- Gastrointestinal bleeding (GIB) is categorized as overt (hematemesis, melena, hematochezia) or occult (anemia, positive fecal occult blood).
- Upper GIB (UGIB) accounts for ~50% of GIB hospitalizations, with peptic ulcers as the most common cause.
- Lower GIB (LGIB) is often due to diverticulosis, hemorrhoids, or vascular ectasias, with diverticular bleeding being abrupt and painless.
- The Glasgow-Blatchford score guides risk stratification for UGIB, with scores ≤ 1 indicating low risk for rebleeding or mortality.
- Endoscopic therapy (e.g., PPI, hemostatic agents) is the first-line treatment for high-risk UGIB, while surgical intervention is reserved for refractory cases.
1. DEFINITION & OVERVIEW¶
Gastrointestinal bleeding (GIB) is classified as overt (visible blood) or occult (subtle signs of blood loss). Overt GIB includes hematemesis, melena, and hematochezia, while occult GIB presents with anemia or positive fecal occult blood. GIB is further categorized by anatomical location: upper (esophagus, stomach, duodenum), lower (colon, small intestine), or obscure (unknown source).
Table 51-1 Glasgow-Blatchford Score¶
| RISK FACTORS AT ADMISSION | SCORE | |
|---|---|---|
| Blood urea nitrogen (mg/dL) | 18.2 to <22.4 | 2 |
| Blood urea nitrogen (mg/dL) | 22.4 to <28.0 | 3 |
| Blood urea nitrogen (mg/dL) | 28.0 to <70.0 | 4 |
| Blood urea nitrogen (mg/dL) | ‡70.0 | 6 |
| Hemoglobin (g/dL) | 12.0 to <13.0 (men); 10.0 to <12.0 (women) | 1 |
| Hemoglobin (g/dL) | 10.0 to <12.0 (men) | 3 |
| Hemoglobin (g/dL) | <10.0 | 6 |
| Systolic blood pressure (mmHg) | 100–109 | 1 |
| Systolic blood pressure (mmHg) | 90–99 | 2 |
| Systolic blood pressure (mmHg) | <90 | 3 |
1.1 Overt vs. Occult Bleeding¶
Overt GIB manifests as hematemesis (vomited blood), melena (black tarry stool), or hematochezia (bright red blood). Occult GIB presents with symptoms of blood loss (e.g., lightheadedness, syncope) or iron-deficiency anemia. Diagnosis requires fecal occult blood testing or endoscopic evaluation.
1.2 Upper vs. Lower GIB¶
Upper GIB (UGIB) originates from the esophagus, stomach, or duodenum, while lower GIB (LGIB) arises from the colon or small intestine. UGIB is more commonly associated with peptic ulcers, varices, or erosions, whereas LGIB often involves diverticula, vascular ectasias, or neoplasms.
2. EPIDEMIOLOGY¶
UGIB accounts for ~530,000 annual hospitalizations in the U.S., with a case fatality rate of ~2%. LGIB is less common but also significant. Risk factors include older age, NSAID use, H. pylori infection, portal hypertension, and comorbidities like cirrhosis or cardiovascular disease.
2.1 Incidence and Mortality¶
UGIB is the most common gastrointestinal condition leading to hospitalization, with ~530,000 annual admissions. Mortality is ~2%, primarily due to complications of underlying illnesses rather than exsanguination.
2.2 Demographics¶
UGIB is more common in men, while LGIB is more prevalent in older adults. Risk factors include age >65, NSAID use, H. pylori infection, and portal hypertension.
3. ETIOLOGY & PATHOPHYSIOLOGY¶
UGIB is caused by peptic ulcers, varices, erosions, or Mallory-Weiss tears. LGIB often involves diverticulosis, vascular ectasias, or neoplasms. Stress-related mucosal injury occurs in critically ill patients, while occult bleeding may arise from ischemia or neoplasms.
3.1 Upper GIB Sources¶
Peptic ulcers (50% of UGIB cases), esophageal varices, Mallory-Weiss tears, and erosions. NSAID use, H. pylori, and acid hypersecretion are key pathogenic factors.
3.2 Lower GIB Sources¶
Diverticulosis (most common), hemorrhoids, vascular ectasias, and neoplasms. Chronic bleeding from diverticula is common, with spontaneous cessation in ~90% of cases.
4. CLINICAL FEATURES¶
UGIB presents with hematemesis, melena, or hematochezia. LGIB is often painless with hematochezia. Occult bleeding may present with anemia, syncope, or iron-deficiency. Hemodynamic instability (tachycardia, hypotension) indicates significant blood loss.
4.1 Symptoms and Signs¶
Hematemesis (bright red blood), melena (black tarry stool), hematochezia (bright red blood), syncope, lightheadedness, and iron-deficiency anemia. Hemodynamic instability (tachycardia, hypotension) indicates significant blood loss.
4.2 Complications¶
Hypovolemic shock, anemia, and mortality from underlying comorbidities. Rebleeding is common in high-risk ulcers or variceal bleeding.
5. DIFFERENTIAL DIAGNOSIS¶
Differentiate UGIB from LGIB using hematemesis (UGIB) vs. hematochezia (LGIB). Exclude other causes like hemobilia, hematemesis from gastritis, or melena from upper GI bleeding.
5.1 UGIB vs. LGIB¶
Hematemesis and melena suggest UGIB, while hematochezia indicates LGIB. However, brisk bleeding from an upper lesion may mimic LGIB. Bile-stained nasogastric aspirate may suggest UGIB, but is not definitive.
6. INVESTIGATIONS & DIAGNOSIS¶
Initial assessment includes vital signs, hemoglobin, and Glasgow-Blatchford score. Endoscopy is the gold standard for diagnosis and therapy. Imaging (CT angiography, angiography) is used for obscure bleeding.
6.1 Diagnostic Algorithms¶
UGIB: Endoscopy within 24 h. LGIB: Colonoscopy or CT angiography. Obscure bleeding: Angiography or surgical exploration. Glasgow-Blatchford score guides risk stratification and disposition.
6.2 Laboratory Tests¶
CBC, electrolytes, renal function, coagulation profile, and fecal occult blood. Hemoglobin may be normal early in acute bleeding due to plasma dilution.
7. MANAGEMENT & TREATMENT¶
Initial management includes PPIs, hemodynamic stabilization, and endoscopic therapy. Surgical intervention is reserved for refractory cases. Anticoagulants and NSAIDs require careful management.
7.1 Endoscopic Therapy¶
High-dose PPIs, hemostatic agents (e.g., epinephrine, clips), and endoscopic ligation for varices. Endoscopic therapy reduces rebleeding and mortality in high-risk ulcers.
7.2 Medical Management¶
PPIs for acid suppression, octreotide for variceal bleeding, and antibiotics for infected ulcers. Avoid NSAIDs in patients with active bleeding.
7.3 Surgical Intervention¶
Resection for refractory diverticular bleeding or massive small intestinal bleeding. TIPS for recurrent variceal bleeding in cirrhosis.
8. PROGNOSIS & COMPLICATIONS¶
Mortality is ~2% for UGIB, primarily due to comorbidities. Rebleeding rates are high in high-risk ulcers (42% at 7 years without PPI). Complications include anemia, hypovolemic shock, and mortality from underlying disease.
8.1 Mortality and Rebleeding¶
UGIB mortality is ~2%, with rebleeding rates up to 45% in high-risk ulcers. Variceal bleeding has higher mortality due to portal hypertension and liver disease.
8.2 Long-Term Outcomes¶
Patients with chronic occult bleeding may develop iron-deficiency anemia. PPI therapy reduces rebleeding in ulcers and varices.
9. SPECIAL CONSIDERATIONS¶
In elderly patients, weight loss or anorexia may mask GI bleeding. Pregnancy requires careful management of anticoagulants and NSAIDs. Cirrhotic patients with variceal bleeding need octreotide and antibiotics.
9.1 Elderly Patients¶
Elderly patients may present with atypical symptoms (e.g., syncope) and have higher comorbidity rates. PPIs are preferred for acid suppression.
9.2 Cirrhosis and Varices¶
Variceal bleeding in cirrhosis requires endoscopic ligation, octreotide, and TIPS for refractory cases. PPIs are contraindicated in patients with severe hepatic encephalopathy.
10. KEY POINTS & CLINICAL PEARLS¶
- Use the Glasgow-Blatchford score to guide disposition for UGIB. 2. Endoscopic therapy is the first-line treatment for high-risk UGIB. 3. Diverticular bleeding is the most common cause of LGIB. 4. PPIs reduce rebleeding in ulcers and varices. 5. Avoid NSAIDs in patients with active GI bleeding.