NMS. Casos Clínicos

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Chapter 8 ♦ Lower Gastrointestinal Disorders

Once the resuscitation is under way, it is necessary to take a more careful history and perform a more detailed physical examination to evaluate for preexisting diseases, prior surgery, and other problems that might influence decision-making. Constant reevaluation of the resuscitation should be a high priority. Q: What are the most likely diagnoses? A: The most common causes of rapid lower GI bleeding are bleeding diverticula and vas- cular ectasias . Other causes of bright red blood per rectum include Meckel diverticu- lum, aortoenteric fistula, ischemic colitis, IBD, hemorrhoidal disease, and rectal varices. Colonic neoplasms are also a possibility, although colon cancer rarely causes massive lower GI bleeding. After receiving IV fluids, the patient’s BP and heart rate improve, and the patient seems more energetic. Laboratory studies reveal a hematocrit of 38% and a mildly elevated serum Na at 148 mEq/L and a blood urea nitrogen (BUN) of 30 mg/dL. Since your initial exam, there has been no further rectal bleeding. The NG aspirate contains bile, and anoscopy reveals no bleeding source. Q: What are the next management steps? A: Admission for stabilization, observation for further GI bleeding, and diagnostic workup is warranted. Close monitoring in an intermediate or intensive care unit is necessary. Although the initial hematocrit is 38%, it takes several hours for the hematocrit to equili- brate before it is an accurate measure of blood cell volume; it should be checked frequently. If it continues to decrease, a blood transfusion may still be required. The patient has remained stable overnight with a heart rate of 80 beats per minute, a normal BP with no orthostatic changes, and a hematocrit that has drifted down to 32%. No further episodes of rectal bleeding have occurred. The patient is currently hungry and feeling much better. Q: What is the likelihood that this patient will experience another episode of bleeding? A: The likelihood that the patient will bleed again depends on the cause of the GI bleed. The natural course of diverticular bleeds is to stop spontaneously . Bleeding colonic divertic- ula have less than 25% likelihood of rebleeding, although 20% of affected patients continue to bleed and require operative intervention. Patients with vascular ectasias stop bleeding spontaneously in about 90% of cases , although the risk of rebleeding is approximately 25% and 46% after 1 year and 3 years, respectively. Q: What is the next step? A: It is necessary to determine the cause of the GI bleed. In this case, in which the bleeding has stopped, the most valuable procedure is colonoscopy . Whether colonoscopy is performed during this admission or as an out- patient, it is critical to not overlook this procedure. Although colon cancer is unlikely, a missed cancer is a major oversight. If it occurs during admission, a bowel “prep” is appropriate. If vascular ectasia is evident, treatment with coagulation with a monopolar current is appropriate. The most significant risk is colonic perforation from colonic coagula- tion. Bleeding colonic diverticula are not amenable to endoscopic treatment , but this approach does permit localization of the bleeding site on occasion. Bleeding polyps may be SAMPLE