A 72-year-old man with end-stage renal disease comes to the emergency department due to abdominal pain for the past 6 hours. The pain started in the lower left abdomen at the end of the hemodialysis session and has remained steady in intensity. The pain does not radiate and is unchanged with movement. The patient rushed to the hospital after noticing bright red blood in the bowel movement 30 minutes ago. He has had mild nausea but no vomiting, back pain, fever, or urinary symptoms. Medical problems include hypertension, type 2 diabetes mellitus, hyperlipidemia, depression, and gastritis. The patient developed anuric end-stage renal disease due to hypertensive and diabetic nephropathy and has been receiving maintenance hemodialysis for the past several years. He reports no recent antibiotic use or travel and has not eaten anything out of the ordinary. The patient is a former smoker with a 30-pack-year history and does not use alcohol or illicit drugs.
Temperature is 37.4 C (99.3 F), blood pressure is 110/80 mm Hg, pulse is 88/min and regular, and respirations are 16/min. Abdominal examination shows tenderness in the left lower quadrant with decreased bowel sounds, but there is no rebound tenderness or rigidity. Rectal examination reveals stool mixed with bright red blood.
Laboratory results are as follows:
Which of the following is the best next step in management of this patient?

Question

A 72-year-old man with end-stage renal disease comes to the emergency department due to abdominal pain for the past 6 hours.  The pain started in the lower left abdomen at the end of the hemodialysis session and has remained steady in intensity.  The pain does not radiate and is unchanged with movement.  The patient rushed to the hospital after noticing bright red blood in the bowel movement 30 minutes ago.  He has had mild nausea but no vomiting, back pain, fever, or urinary symptoms.  Medical problems include hypertension, type 2 diabetes mellitus, hyperlipidemia, depression, and gastritis.  The patient developed anuric end-stage renal disease due to hypertensive and diabetic nephropathy and has been receiving maintenance hemodialysis for the past several years.  He reports no recent antibiotic use or travel and has not eaten anything out of the ordinary.  The patient is a former smoker with a 30-pack-year history and does not use alcohol or illicit drugs.
Temperature is 37.4 C (99.3 F), blood pressure is 110/80 mm Hg, pulse is 88/min and regular, and respirations are 16/min.  Abdominal examination shows tenderness in the left lower quadrant with decreased bowel sounds, but there is no rebound tenderness or rigidity.  Rectal examination reveals stool mixed with bright red blood.
Laboratory results are as follows:
 Which of the following is the best next step in management of this patient?

Quizplus · Accepted Answer

11ec193a_9609_b977_853d_b53114eb7013_MD0002_00 This patient's presentation of acute-onset abdominal pain and hematochezia is typical for colonic ischemia, the most common form of ischemic bowel disease affecting the elderly. Colonic ischemia is usually due to hypovolemia or decreased effective arterial blood volume, leading to an abrupt and temporary decrease in blood flow to the watershed areas (eg, splenic flexure, rectosigmoid colon). Hemodialysis, myocardial infarction, major vascular surgery, strenuous exercise (eg, long-distance running), or drugs (eg, diuretics) can increase the risk of ischemic colitis. Abdominal CT scan with intravenous contrast is preferred (including in anuric patients on hemodialysis) to rule out extensive bowel damage indicating the need for colonic resection. However, imaging may show nonspecific findings. Colonoscopy (without bowel preparation or air insufflation to prevent perforation) is usually done subsequently to confirm the diagnosis of ischemic colitis (Choice A). It may show pale mucosa with petechial bleeding, bluish hemorrhagic nodules, or cyanotic mucosa with hemorrhage. (Choice C) Because most cases of colonic ischemia are nonocclusive, MR angiography is not useful for diagnosis due to the low possibility of finding a thrombus or embolus. Moreover, gadolinium contrast dye should not be used in patients with significant renal impairment due to the risk for nephrogenic systemic fibrosis. (Choice D) Clostridium difficile colitis may present similarly to ischemic colitis with lower quadrant abdominal pain, leukocytosis, and diarrhea; however, this patient lacks recent antibiotic exposure and frank hematochezia is rare in C difficile infection. (Choice E) This patient is hemodynamically stable and has no signs of upper gastrointestinal bleed (eg, hematemesis, melena); therefore, upper endoscopy is not indicated. Educational objective: Ischemic colitis usually presents with abrupt onset of abdominal pain over the affected large bowel, with subsequent hematochezia. CT scan is the preferred initial diagnostic study to rule out extensive bowel injury. Diagnosis is subsequently confirmed with colonoscopy. __________ References: Clinical approach to colonic ischemia. (http://www.ncbi.nlm.nih.gov/pubmed/19570972)

A 72-Year-Old Man with End-Stage Renal Disease Comes to the Emergency