Gastrointestinal Bleeding
Bleeding of the GI tract may manifest clinically as hematemesis (vomiting of blood), melena (passage of black tarry stools), or hematochezia (passage of red bloody stools).
The GI tract has many potential sites of bleeding. The most common sites, in descending order, are the anorectum, stomach, colon, small intestine, and esophagus. Blood that originates in the mouth, the nasopharynx, or the lung can be swallowed and mimic gastric bleeding. The liver, pancreas, and aorta are unusual bleeding sites.
In the elderly, hemorrhoids and colorectal cancer are the most common causes of minor bleeding; peptic ulcer, diverticular disease, and angiodysplasia are the most common causes of major bleeding. Massive GI bleeding is tolerated poorly by elderly patients. Diagnosis must be made quickly, and treatment must be started sooner than in younger patients, who can better tolerate repeated episodes of bleeding.
Resuscitation: While evaluation is being performed, the patient must be adequately resuscitated. Patients who present with bleeding must have adequate IV access (two large-bore IV lines) in anticipation of hemodynamic compromise. While giving large volumes of fluid to elderly patients often frightens clinicians, inadequate replacement is potentially lethal. A Foley catheter should be placed to assess adequacy of resuscitation while awaiting results of renal function tests. It is important to note that, with aging, renal concentrating ability decreases, so that urine output may continue in the face of decreasing intravascular volume until the patient suddenly becomes anuric. Especially for debilitated patients with hypotension or brisk upper GI bleeding, endotracheal intubation may be needed for airway protection.
Diagnosis
The history, physical examination, blood tests, endoscopy, selective arteriography, radionuclide studies, barium contrast studies, and exploratory laparotomy aid in identifying the bleeding site. Often, determining whether bleeding originates in the upper or lower GI tract is difficult. Thus, ongoing diagnostic evaluation and treatment are essential while bleeding continues.
The history provides important clinical information. Alcoholism and a previous massive upper GI hemorrhage suggest bleeding caused by esophageal varices in young adults, but in elderly patients, the more likely cause is peptic ulcer disease. If a patient has an aortic aneurysm or an abdominal aortic graft, erosion into the duodenum should be suspected. Massive colonic bleeding is most likely caused by diverticular disease or angiodysplasia. Streaks of red blood on the toilet paper usually indicate hemorrhoids, but polyps and cancer must be ruled out.
Aspirin ingestion may explain GI bleeding. One aspirin tablet can prolong bleeding times for at least 6 days, while a larger dose can cause aspirin-induced gastritis. Nevertheless, the physician should not be influenced too strongly by such a history, because many patients who take aspirin bleed from other causes. Alcohol, anticoagulants, nonsteroidal anti-inflammatory drugs (eg, ibuprofen), and coagulopathies (eg, those associated with metastatic disease or chemotherapy) may cause gastritis or bleeding, and the origin of such bleeding may not be determined by endoscopy or an operation.
Physical examination can help estimate the amount of bleeding. As a rough guide, orthostatic hypotension suggests a 15 to 25% blood loss; shock while recumbent represents at least a 30 to 40% loss. Pulse and blood pressure must be monitored whenever continued or recurrent bleeding is suspected. Hepatomegaly suggests portal hypertension or metastatic disease. Rectal and vaginal examinations are essential. Palpable masses along the course of the colon suggest colon cancer; masses in the left hypogastrium suggest gastric cancer.
Blood tests include serial Hct or hemoglobin levels, red blood cell and platelet counts, and smears for red blood cell, white blood cell, and platelet morphologic studies. Microcytosis can indicate chronic bleeding, even if acute bleeding is superimposed. Determinations of prothrombin time and partial thromboplastin time should be promptly performed routinely; these tests are essential if the patient is taking anticoagulants or has jaundice. Electrolytes, blood urea nitrogen, and creatinine should be measured to assess renal function; results aid in determining whether the patient is significantly fluid-depleted. All patients with bright red blood issuing from the mouth or anus must have adequate blood samples with the blood banking laboratory.
Nasogastric lavage is an essential diagnostic procedure for all patients with bright red bleeding from the mouth or anus. If the nasogastric tube returns bloody fluid, then saline lavage should be performed until the effluent is clear and then endoscopy performed. If the tube returns bilious nonbloody fluid, then the source of bleeding is most likely distal to the ligament of Treitz and colonoscopy should be performed first. If nasogastric lavage is nonbloody but no bile returns, then both colonoscopy and esophagogastroduodenoscopy should be performed.
Endoscopy (including esophagogastroduodenoscopy, anoscopy, rigid sigmoidoscopy, flexible sigmoidoscopy, and colonoscopy) can be used diagnostically and therapeutically and should be performed as rapidly as the patient's clinical status allows. The route of first approach (upper or lower) is determined from the results of nasogastric tube lavage. Often, a bleeding lesion in the stomach or duodenum can be controlled by a heater probe, bipolar electrocautery, or epinephrine injection. For colonoscopy, brisk bleeding is usually sufficiently cathartic that no other preparation is needed in the acute setting; however, colonoscopy is most accurate when the patient is bleeding slowly enough to allow a preprocedure polyethylene glycol preparation. For the patient with brisk lower GI bleeding in whom colonoscopy reveals no lesion and no blood in the proximal colon, anoscopy is mandatory; often a bleeding hemorrhoid or a rectal ulcer can be controlled with epinephrine injection and sutures. If bleeding continues and adequate endoscopic examination has been performed, the following procedures should be considered.
Selective arteriography is important for identifying the bleeding site (especially in patients for whom endoscopy has not localized the bleeding point) provided blood loss is >= 0.5 to 1.0 mL/minute. This procedure helps localize lesions in the stomach, small bowel, and colon and may be combined with exploratory laparotomy.
Two types of radionuclide studies are generally used in adults. The most common requires withdrawing about 10 mL of blood, labeling red blood cells with a technetium radionuclide, and reinjecting them into the patient. The procedure, which takes about an hour, demonstrates the bleeding site if the loss is >= 0.1 to 0.5 mL/minute, even if bleeding is intermittent. The second study involves injecting the patient with a prepared sulfur colloid radionuclide. If the patient is bleeding, the bleeding site can be identified in a few minutes. Both methods are less useful with upper GI bleeding because of the amount of background scatter. Technetium scans occasionally demonstrate Meckel's diverticulum because of selective uptake by gastric mucosa, which may be present in the lesion; however, Meckel's diverticulum is a rare cause of bleeding in elderly patients.
Barium contrast studies can be sensitive and specific but should be used only when endoscopy, selective arteriography, and radionuclide studies are unavailable. Barium studies cannot determine whether a structural abnormality is bleeding, and the presence of barium in the GI tract can obscure the findings of the more sensitive and specific studies described above.
Laparotomy should be reserved for treating an identified source of bleeding. However, if endoscopy has adequately excluded a gastric, duodenal, esophageal, or colonic lesion or if angiography indicates a lesion in the small bowel, exploratory laparotomy may be appropriate. Examination of the abdominal viscera, especially the small bowel, can identify many lesions (eg, angiomas, leiomyomas, diverticula). Selective arteriography during exploratory laparotomy might help identify bleeding lesions in the small bowel, allowing resection of the involved segment, but this modality is unlikely to be available to most general surgeons.
Prognosis and Treatment
For patients > 60, the mortality rate is close to zero if patients undergo immediate surgery and is about 15% if they are first treated medically but then require surgery for persistent or recurrent bleeding.
Treating an elderly person who has bleeding other than minor rectal bleeding, tarry stools, or hematemesis as an outpatient is dangerous. Bleeding assumed to be from hemorrhoids or other limited rectal bleeding requiring only diagnostic colonoscopy or barium enema may be treated in an outpatient setting, provided time is not lost in making the diagnosis.
A nasogastric tube may clear bleeding by lavage. For upper GI bleeding, if blood does not clear with lavage, a choice must be made between selective arteriography and immediate exploratory laparotomy; patients with massive GI bleeding can experience cardiovascular collapse in the angiographic suite. Consequently, the operating room is the safest place for a briskly bleeding patient. Once the patient is in the operating room, an attempt at therapeutic endoscopy before laparotomy is acceptable if the patient is stable.
Essentially the same therapeutic choices are applicable whether the bleeding site is in the stomach, duodenum, or colon. The choice depends on the patient's age and cardiovascular status and the rate and quantity of blood loss. Options include expectant treatment by medical measures (eg, intubation, lavage), endoscopy using electrocoagulation or heater probe, selective arteriography with local or peripheral vasopressin or octreotide (a long-acting somatostatin analog) infusion or embolization, and surgery.
When the bleeding site has been identified using selective arteriography, the catheter may be used to inject vasopressin directly. This injection immediately controls bleeding in > 80% of cases. Peripheral vasopressin 0.4 U/minute (or octreotide) is also an option, although caution is necessary because cardiac arrhythmias occur. If the vasopressin infusion fails, embolization with an absorbable gelatin sponge or coils may be attempted. However, there is danger of postembolic necrosis arising in the wall of a viscus or of the liver from a dislodged embolus.
At times, bleeding is so massive that emergency surgery is the only reasonable treatment. If a patient is apparently bleeding from the stomach or the colon but the bleeding site cannot be determined and severe blood loss continues, the only option is to perform a blind gastrectomy or colectomy.
Bleeding in the Esophagus
Esophagitis may cause slow but persistent bleeding. Treatment with H2 blockers or proton pump inhibitors usually is very helpful because bleeding results from ulceration due to acid reflux. However, cancer must be excluded by endoscopy and biopsy. Severe bleeding requiring surgery rarely occurs in the elderly.
Varices secondary to portal hypertension are uncommon in the elderly. The initial symptom is usually massive upper GI hemorrhage. When varices occur, the primary treatment is immediate endoscopic sclerotherapy or endoscopic variceal ligation. If this treatment is unavailable, a Sengstaken-Blakemore tube is inserted.
Bleeding in the Stomach
Mallory-Weiss tears usually result from repeated vomiting. They can be identified and often cauterized or hemostatically injected through the endoscope. When necessary, surgery involves suturing the lacerations.
Bleeding ulcers are more likely to be gastric ulcers than duodenal ulcers, and controlling bleeding by conservative measures is less certain in gastric than in duodenal ulcers. The usual operation for intractable gastric ulcer bleeding is partial gastrectomy with or without vagotomy. The usual procedure for duodenal ulcer bleeding is ligation of the bleeding vessel and gastric resection or pyloroplasty and vagotomy.
Anastomotic ulcers may occur just distal to the suture line in patients who had previous peptic surgery even after medical measures stop the bleeding; these ulcers occur commonly when vagotomy or posterior gastroenterostomy is performed. Gastric resection and vagotomy are usually indicated.
Gastritis can cause bleeding; if bleeding is not controlled medically, only a radical subtotal gastrectomy with vagotomy or total gastrectomy achieves hemostasis.
Stress ulcers are similar to gastritis but occur after trauma, surgery, burns, or infections. Nasogastric suction, sucralfate, IV H2 blockers, proton pump inhibitors, or oral antacids to control gastric pH and IV alimentation are the main medical treatments for bleeding from stress ulcers, gastritis, or peptic ulcer disease. Endoscopic electrocoagulation often is successful. Laser coagulation is dangerous because of the risk of perforation. Nasogastric intubation is necessary to keep the stomach empty, to monitor bleeding, and to administer antacids.
Vascular lesions (cirsoid [racemose] aneurysm, or Dieulafoy's ulcer) are localized arteriovenous malformations and communications in the gastric mucosa. More common in the fundus, they may be impossible to see during endoscopy or surgery unless they are bleeding. If they are bleeding, endoscopic therapy is sometimes possible. Surgically, these lesions require simple oversewing or limited excision; occasionally, a high or total gastrectomy is necessary to achieve hemostasis.
Tumors may cause any type of bleeding. Slow, persistent bleeding is more typical of malignant than benign tumors. Benign leiomyomas often lead to massive bleeding that requires emergency laparotomy.
Bleeding in the Small Intestine
Diverticular disease can lead to massive bleeding. Meckel's diverticulum of the distal ileum may rarely produce an ulcer of the adjacent normal ileal mucosa, leading to bleeding. Varices secondary to portal hypertension at times may involve the small intestine and lead to bleeding. Multiple arteriovenous malformations usually are discovered in children but also may develop later in life.
Tumors, although uncommon in the small intestine, may produce bleeding. Massive bleeding usually results from large leiomyomas. Slow, persistent bleeding is more typical of angiomas.
Bleeding in the Colon
Angiodysplasia and diverticular disease cause massive bleeding and occur with equal frequency in the elderly. Angiodysplasia refers to small (1 to 5 mm in diameter) single or multiple lesions found chiefly in the cecum or ascending colon and resembling submucosal arteriovenous malformations on microscopy. The average age at diagnosis for angiodysplasia and bleeding diverticula is 70 years.
The diagnosis of angiodysplasia can be made by colonoscopy in some cases, and the lesions can be destroyed by electrocoagulation. However, if bleeding is profuse, selective arteriography is the best diagnostic modality. The characteristic angiographic finding in angiodysplasia is an early-filling vein in the region of the ileocecal valve.
Carcinoma of the cecum may first present as anemia. Many tumors are diagnosed on the basis of a positive stool occult blood test. With cancer or a polyp, the amount of visible blood in the stool is usually small.
The exact cause of massive bleeding from the colon cannot be determined in about 10% of cases. In these cases, the surgeon performs a subtotal colectomy; the ileorectal anastomosis is placed within reach of the rigid sigmoidoscope, or < 25 cm from the anal verge (anastomosis just above the sacral promontory usually suffices).
Bleeding in the Liver and Pancreas
Trauma is the cause of bleeding from the liver and pancreas in nearly all cases. Diagnosis is made during abdominal CT with IV contrast (when a blush of arterial bleeding is noted), by selective arteriography (in which case therapeutic embolization is an option), or during exploratory laparotomy (in which bleeding vessels are oversewn).
Bleeding in an Aortic Graft
In elderly patients, a relatively sudden onset of massive GI bleeding can occur months or years after an abdominal aortic aneurysm has been excised and replaced with a vascular graft. A fistula between the graft and the small intestine is the most likely cause. Although aortoduodenal fistulas predominate, erosion into any section of the small intestine may occur. Endoscopy to the distal duodenum is usually diagnostic. Arteriography also may be helpful.
Treatment is difficult because infection is common and is a strong deterrent to graft replacement. The usual procedure is to remove the graft and establish an extra-anatomic bypass graft, usually between axillary and femoral arteries.
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