Lower Gastrointestinal Bleeding
52 LOWER GASTROINTESTINAL BLEEDING
Kathleen Liscum M.D.
1. Describe the treatment of a patient who presents with lower gastrointestinal (GI) bleeding.
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Treatment begins with the ABCs (airway, breathing, circulation). Place two large-bore intravenous (IV) catheters in the upper extremities. Obtain hemoglobin and hematocrit levels, blood type, and cross-match. A Foley catheter should be placed to help monitor volume status.
2. What is the next step in evaluating the patient?
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A nasogastric tube should be placed to rule out an upper GI source. If the aspirate is bilious, the examiner can be fairly certain that the source is distal to the ligament of Treitz. However, if the aspirate reveals no bile, the patient may still be bleeding in the duodenum with a competent pylorus.
3. What are the two most common causes of massive lower GI bleeding?
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Diverticular hemorrhage (diverticulosis) and bleeding vascular ectasias. Diverticular disease was previously thought to be the most common cause of lower GI bleeding, but vascular ectasias are now quite frequent.
4. What are the other causes of blood per rectum? Show answer
* Colon cancer
* Polyps
* Ischemic colitis
* Infectious colitis
* Inflammatory bowel disease
* Anorectal disorders (e.g., hemorrhoids, fissure)
* Meckel’s diverticulum
5. After a thorough history and physical examination, what is the first step toward identifying the specific site of bleeding?
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Anoscopy and rigid proctosigmoidoscopy to rule out anorectal fissures and an extraperitoneal source.
6. Name four options for localizing lower GI bleeding.
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1. Tagged red blood cell scan
2. Sulfur colloid scan
3. Angiography
4. Colonoscopy
7. Discuss the differences between sulfur colloid scan and tagged red blood cell (RBC) scan.
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The sulfur colloid scan can be accomplished quickly and detects bleeding as minimal as 0.1 mL/min. The radiolabeled sulfur colloid is cleared quickly by the liver and spleen, which may obscure the bleeding site if it is located in the hepatic or splenic flexure. The test is complete within 20 minutes of administration of the radionuclide.
The tagged red blood cell scan requires a 60-minute delay while the autologous RBCs are labeled with isotope. The test detects bleeding as slow as 0.5 mL/min. Because the tagged cells stay in the patient’s system, it is also helpful in identifying the source when the patient is bleeding intermittently. The study takes at least 2 hours.
8. What is the role of angiography?
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Angiography detects bleeding rates of 0.5-1.0 mL/min but only if the patient is actively bleeding. When a bleeding site is identified, the angiographic appearance may provide further insight into the cause of the bleeding. Whereas diverticular bleeding is often seen as extravasation of contrast, vascular ectasias may be identified by a vascular tuft or early filling vein.
9. What therapeutic options are available with angiography?
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(1) Infusion of vasopressin (Pitressin) into a selected vessel and (2) embolization of the bleeding vessel.
KEY POINTS: LOWER GI BLEEDING
1. The most common causes of massive lower GI bleeding are diverticular hemorrhage and bleeding vascular ectasias.
2. The most common cause of lower GI bleeding in children is Meckel’s diverticulum.
3. After a thorough history and physical exam, the first steps in identifying the specific site of bleeding are anoscopy and rigid proctosigmoidoscopy.
4. Tagged red blood cell scan, sulfur colloid scan, colonoscopy, and angiography are four options for localizing lower GI bleeding.
5. Indications for surgery include patients who have received 6 U of blood without resolution of bleeding and patients who continue to bleed after vasopressin or embolization.
10. Which patients should have angiographic embolization of the bleeding site?
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Most surgeons believe that embolization should be reserved for patients who are poor operative risks in that a 15% complication rate is associated with the procedure. Patients may perforate or develop a stricture as a result of bowel wall ischemia.
11. What is the role of vasopressin infusion?
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Vasopressin is only a temporizing measure. Control of the bleeding with vasopressin allows time for resuscitation and essentially converts an emergent case into an urgent one. Vasopressin occasionally may be used as the only treatment for diverticular bleeding. If the patient has a repeated episode of bleeding after weaning from vasopressin, the surgeon must decide between embolization and surgery.
12. Do lower GI hemorrhages ever spontaneously resolve?
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Spontaneous resolution occurs in 75% of patients with vascular ectasias and 90% of patients with diverticular bleeding.
13. What are the indications for operative intervention?
Show answer
When the patient has received 6 units of blood (two thirds of the patient’s blood volume in 24 hours) without resolution of bleeding. Any patient who continues to bleed or has recurrent bleeding after vasopressin or embolization should undergo resection.
14. What is the role of blind subtotal colectomy in the management of patients with massive lower GI bleeding?
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Blind subtotal colectomy is limited to the small group of patients in whom a specific bleeding source cannot be identified. The procedure is associated with a 16% mortality rate. Younger patients tend to tolerate the procedure better than elderly patients. Older patients often suffer with severe diarrhea, urgency, and incontinence. However, blind segmental colectomy is associated with an even higher mortality rate (40%) and a 50% rebleeding rate.
15. What is the most common cause of lower GI hemorrhage in the pediatric population?
Show answer
Meckel’s diverticulum.
References
BIBLIOGRAPHY
1. American Society for Gastrointestinal Endoscopy: The role of endoscopy in the patient with lower gastrointestinal bleeding. Gastrointest Endosc 48:685-688, 1998.
2. Belaiche J, Louis E, D’Haens G, et al: Acute lower gastrointestinal bleeding in Crohn’s disease: Characteristics of a unique series of 34 patients. Belgian IBD Research Group. Am J Gastroenterol 94:2177-2181, 1999. Full article
3. Cynamon J, Atar E, Steiner A, et al: Catheter-induced vasospasm in the treatment of acute lower gastrointestinal bleeding. J Vasc Interv Radiol 14:211-216, 2003. Medline Similar articles
4. Gunderman R, Leef JA, Lipton MJ, Reba RC: Diagnostic imaging and the outcome of acute lower gastrointestinal bleeding. Acad Radiol Suppl 2:S303-S305, 1998.
5. Mallant-Hent RC, Van Bodegraven AA, Meuwissen SG, Manoliu RA: Alternative approach to massive gastrointestinal bleeding in ulcerative colitis: Highly selective transcatheter embolization. Eur J Gastroenterol Hepatol 15:189-193, 2003. Medline Similar articles Full article
6. So JB, Kok K, Hgoi SS: Right-diverticular disease as a source of lower gastrointestinal bleeding. Am Surg 65:299-302, 1999. Medline Similar articles
7. Wilcox CM, Clark WS: Causes and outcome of upper and lower gastrointestinal bleeding: The Grady Hospital experience. South Med J 92:44-50, 1999. Medline Similar articles
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Abernathy’s Surgical Secrets, Updated Edition (Book w / Student Consult)
Author / s: Harken Alden H., Abernathy Charles, Moore Ernest Eugene
Year: 2004
Pages: 473
Publishers: Elsevier Mosby; 5th Bk & Acc edition
ISBN: 0323034160
