A 27-year-old man comes to the physician because of a 10-day history of crampy lower abdominal pain and diarrhea that awakens him at night. He says he might have some blood in his stool, but he is not sure. He also complains of fatigue. His past medical history is unremarkable. He takes a daily multivitamin and exercises regularly. He has a stable male partner and uses condoms regularly. His mother died of lymphoma and his older brother suffers from ulcerative colitis.
He is afebrile. His blood pressure is 130/88 mm Hg, pulse is 90/min, and respirations are 12/min. His bowel sounds are normoactive. There is mild abdominal tenderness in both lower quadrants without rebound tenderness. His examination is otherwise unremarkable.
The patient's labs reveal:

Which of the following is the best next step in managing this patient?

Question

A 27-year-old man comes to the physician because of a 10-day history of crampy lower abdominal pain and diarrhea that awakens him at night.  He says he might have some blood in his stool, but he is not sure.  He also complains of fatigue.  His past medical history is unremarkable.  He takes a daily multivitamin and exercises regularly.  He has a stable male partner and uses condoms regularly.  His mother died of lymphoma and his older brother suffers from ulcerative colitis.
He is afebrile.  His blood pressure is 130/88 mm Hg, pulse is 90/min, and respirations are 12/min.  His bowel sounds are normoactive.  There is mild abdominal tenderness in both lower quadrants without rebound tenderness.  His examination is otherwise unremarkable.
The patient's labs reveal:

Which of the following is the best next step in managing this patient?

Quizplus · Accepted Answer

11ec193a_98f2_f74a_853d_d9d90689c4b7_MD0002_00 This patient's presentation (anemia, thrombocytopenia, and acute kidney injury after a recent diarrheal illness) is concerning for hemolytic-uremic syndrome (HUS), most commonly caused by a shiga toxin-producing enterohemorrhagic E. coli. HUS is more common in children (but can also be seen in adults) and is similar to thrombotic thrombocytopenic purpura (TTP), which is more commonly seen in adults. However, HUS is associated with more renal disease and fewer primary neurological symptoms than TTP. E. coli The diagnosis of HUS is made clinically in patients who present with the classic triad after a prodromal diarrheal illness. As a result, a peripheral blood smear should be done next to look for schistocytes (fragmented blood cells), indicating a microangiopathic hemolytic anemia. (Choice A) Antimotility drugs (anticholinergics and narcotics) do not decrease the gastrointestinal symptoms, but can worsen HUS by increasing the risk of central nervous system dysfunction. As a result, antimotility agents are not recommended for a patient with suspected HUS from enterohemorrhagic E. coli. E. coli (Choice C) Empiric antibiotics do not decrease the duration of gastrointestinal symptoms and can possibly worsen HUS by increasing shiga toxin release. (Choice D) Sigmoidoscopy is indicated to evaluate for colitis, which can sometimes mimic HUS. However, the thrombocytopenia and renal injury are usually not seen in colitis and makes it less likely in this patient. (Choice E) Stool cultures are not as sensitive to detect enterohemorrhagic E. coli, since the bacteria may only be present in the stool for a few days after the onset of the illness. Serologic testing for E. coli is more sensitive. E. coli E. coli Educational objective: Hemolytic-uremic syndrome is associated with a prodromal diarrheal illness, usually caused by a shiga toxin-producing enterohemorrhagic E. coli leading to microangiopathic hemolytic anemia, thrombocytopenia, and acute kidney injury. The diagnosis is made clinically and can be evaluated with peripheral blood smear to look for schistocytes as well as serologic testing for enterohemorrhagic E. coli. E. coli E. coli __________ References: Sporadic diarrhea-associated thrombotic thrombocytopenic purpura-hemolytic uremic syndrome: an adult and paediatric comparison. (http://www.ncbi.nlm.nih.gov/pubmed/18422775) Hemolytic uremic syndrome associated with Shiga toxin producing Escherichia coli infection in a healthy adult woman. (http://www.ncbi.nlm.nih.gov/pubmed/15335194)

A 27-Year-Old Man Comes to the Physician Because of a 10-Day