A 20-year-old college football player is brought to the emergency department due to fever and worsening abdominal and right flank pain. The day prior, he received a direct blow to the central upper abdomen during a tackle and had to sit out the rest of practice. The patient also has nausea but no emesis or diarrhea. He has no chronic medical conditions. Temperature is 39.4 C (102.9 F). Blood pressure is 100/64 mm Hg, pulse is 112/min, and respirations are 18/min. Heart and lung sounds are normal. The abdomen is diffusely tender with guarding over the epigastrium. Abdominal imaging reveals free air in the retroperitoneum. Which of the following is the most likely diagnosis for this patient?
Approximately 1 day after sustaining blunt abdominal trauma (BAT), this patient has fever, diffuse abdominal tenderness with epigastric guarding, and retroperitoneal free air on imaging. This delayed presentation is concerning for a perforated viscus within the retroperitoneum, such as a duodenal tear.
When a hollow viscus (eg, duodenum, ascending or descending colon) perforates within the retroperitoneum, gastrointestinal spillage may be initially sequestered away from the intraperitoneal space (which is separated from the retroperitoneum by the posterior peritoneal lining). This may delay the development of classic symptoms and signs of perforation (eg, fever, diffuse abdominal pain), as in this patient. In addition, back or flank pain (eg, right flank pain) may be present due to retroperitoneal inflammation.
Aspects of duodenal anatomy that increase the duodenum's susceptibility to perforation include:
Duodenal perforation is typically treated with surgical repair.
(Choices B and D) The stomach and transverse colon are also susceptible to rupture from rapid change in intraluminal pressure during BAT. However, both are intraperitoneal (vs retroperitoneal) structures. Therefore, intraperitoneal free air (eg, free air under the diaphragm on chest x-ray) would be expected on imaging (vs retroperitoneal free air seen in this patient).
(Choices C and E) BAT can injure the pancreas or kidney, causing spillage of pancreatic enzymes or urine into the retroperitoneal space. Although both renal pelvis laceration and traumatic pancreatitis could result in a delayed presentation of abdominal and right flank pain, they would typically cause free fluid rather than free air on imaging.
Educational objective:
Rapid compression of the bowel during blunt abdominal trauma can cause a perforated viscus. When viscus perforation occurs within the retroperitoneum (eg, duodenal tear), classic symptoms and signs (eg, fever, diffuse abdominal pain) may be delayed. Retroperitoneal free air may be present on abdominal imaging.