Presentation
Prior polytrauma, prolonged rehabilitation complicated by C. difficile colitis. Diffuse abdominal pain, guarding and rigidity. ?ileus, perforation
Patient Data
Left lateral decubitus radiographs show grossly distended abdomen with a striking pneumoperitoneum. All large organs including spleen and liver are compressed and displaced towards the midline.
Altogether findings show unequivocal tension pneumoperitoneum. Urgent abdominocentesis was recommended.
Upon emergency abdominocentesis, a large amount of gas was released from the peritoneal space. The patient was subsequently transferred to the CT suite for further evaluation.
Firstly we see that the abdominocentesis has substantially reduced the pneumoperitoneum. The position of the large organs has normalized, thus the most sinister complications such as large vessel compression could be avoided. Copious amount of free gas remains in unusual locations (such as the periportal spaces) too due to the formerly abnormal high intraabdominal pressure. The source of the free air, therefore, cannot be clearly established.
The left colon and sigmoid shows inflammatory wall thickening with mild stranding, thus making these hollow viscera the primary suspects.
Other findings: gallstones, kidney cysts, inguinal hernia on the left, umbilical hernia, prior known vertebral compressions and left radius fracture.
During subsequent laparotomy numerous tiny perforations of the inflamed distal large bowel were found. Thus, considering the poor integrity of the bowel wall an extended Hartmann's resection was performed.
Case Discussion
Tension pneumoperitoneum is a rare clinical condition, and to some extent the risks stem from this. The key point (similarly to tension pneumothorax) is to first reduce the excessive abdominal pressure to avoid imminent fatal complications, and only proceed with further imaging thereafter. The radiologist plays a key role in guiding management, first and foremost to emphasize that pressure reduction has higher priority than cross-sectional imaging.
In my opinion a fulminant toxic megacolon was the most likely underlying condition, leading to multiple small perforations of the bowel wall already weakened by the colitis.
Also contributed by Dr. Gabriella Mirosnyicsenko