Diffuse small-bowel ischemia in hypotensive adults after blunt trauma (shock bowel): CT findings and clinical significance.

OBJECTIVE: The purpose of this study is to describe CT findings of shock bowel (diffuse abnormality of the small bowel observed in hypotensive or hypoperfused patients after blunt abdominal trauma) and to determine the clinical significance of CT-diagnosed shock bowel.
MATERIALS AND METHODS: A data base search of a radiology data registry indicated 13 patients had CT scans obtained at admission that showed diffuse abnormalities of the small bowel and a corresponding medical history of profound clinical shock preceding CT study. All patients sustained blunt abdominal trauma: nine were involved in motor vehicle collisions, three were struck by motor vehicles, and one had a crushing injury. Vehicular impacts were typically high speed, inducing multisystem injury. Admission and follow-up CT studies were reviewed to characterize and assess the evolution of the abdominal CT findings that occur with shock bowel. Medical records were reviewed to determine blood pressure at the accident scene or on admission, surgical findings, and patient outcome.
RESULTS: All patients were severely hypotensive in the field or on admission; three were in cardiac arrest at the scene of the accident. CT scans showed diffuse thickening of the small-bowel wall in all patients, ranging from 7 mm to 15 mm (mean, 11 mm); fluid-filled, dilated small bowel in nine patients; subjectively increased contrast enhancement of the small-bowel wall in six patients; and a flattened inferior vena cava (< 9 mm anteroposterior diameter at renal veins) in 10 patients. The colon appeared normal in all cases. Celiotomy in eight patients revealed normal-appearing small bowel by inspection in two and localized bowel injuries, with the remaining bowel appearing normal in six. Three patients, including one who had celiotomy, had normal-appearing small bowel on repeat CT scans obtained within 5 days of admission, and three had no clinical evidence of small-bowel disease. Three patients died of causes unrelated to bowel pathology.
CONCLUSION: In trauma patients with hypotension, early abdominal CT may show diffuse abnormalities of the small bowel due to prolonged hypoperfusion--shock bowel--with a normal appearing colon. In this study, the CT findings of shock bowel were reversible and were not associated with clinical symptoms.