Successful Colectomy for Hemorrhagic Colitis with Hemolytic Uremic Syndrome and Acute Encephalopathy due to Escherichia coli O157 Infection
An 81-year-old man was admitted to a primary hospital with complaints of lower abdominal pain and bloody diarrhea. He had no specific past medical history. Abdominal computed tomography revealed thickness of the descending colon wall. He was given intravenous hydration and antibiotic therapy (cefotiam, levofloxacin) with a diagnosis of ischemic colitis. On hospital day 2, follow-up abdominal computed tomography showed ascites and thickness of the entire colon wall. On hospital day 4, the patient was transferred to our hospital because of renal dysfunction and a convulsion. In the first aid station, the patient's consciousness was slightly clouded; temperature was 38.0°C, blood pressure 140/92 mm Hg and heart rate 95/min. His skin was cold and moist. The abdomen was distended and tympanic, with generalized tenderness. Laboratory studies revealed severe inflammation, anemia, a low platelet count and renal dysfunction. Blood gas analysis showed hypoxemia, metabolic acidosis and a low CO2 level due to tachypnea. Colonoscopy revealed diffuse mucosal edema, ulcer formation and bleeding from the rectum to the ascending colon (fig. ). There was no evidence of free air, but the whole colon wall was markedly thickened, with huge ascites on abdominal computed tomography (fig. ). Gradually, the patient's vital signs deteriorated (blood pressure 60/40 mm Hg, heart rate 115/min), with severe disturbance of consciousness, and generalized cyanosis could be seen. He was diagnosed as having necrotic ischemic colitis with septic shock and underwent emergency surgery. The operative findings showed a large amount of ascites. From the rectum to the cecum, the colon wall was markedly edematous and sclerotic. In particular, inflammation of the transverse colon extended to the greater omentum with necrosis. An extended right hemicolectomy and ileostomy were performed. The resected specimen showed hemorrhagic necrosis of the transverse colon (fig. ). Pathological findings showed mucosal hemorrhagic necrosis with submucosal edema. There was venous dilatation and congestion of blood, which suggested ischemic colitis. In the stool culture before the operation, O157 and verotoxin were found. This case was therefore diagnosed as hemorrhagic colitis with HUS and acute encephalopathy due to O157 infection. After the operation, the patient was treated in the intensive care unit with ventilation because of delayed emergence from anesthesia due to encephalopathy and poor oxygenation. However, with intensive care, the HUS and encephalopathy improved gradually without dialysis. He was finally discharged on the 33rd postoperative day (fig. ).