"The hypothesised mechanism for ectopic gas production mimicking pseudopneumoperitoneum is by vacuum phenomenon. Rapid changes in local tissue pressure, acute fractures or acute soft tissue disruption can cause dissolution of nitrogen gas from the adjacent soft tissues resulting in small pockets of gas visible on CT 14. The association of benign post-traumatic pseudopneumoperitoneum with high-velocity trauma supports this theory, by the fact that rapid changes in local tissue pressure from an external impact or local tissue disruption (diaphragmatic ligament attachment tears or costochondral microfractures) could create the required microenvironment for vacuum phenomenon."
"Benign post-traumatic pseudopneumoperitoneum is the presence of ectopic gas typically between the 5th-10th intercostal spaces after high-energy trauma in the absence of other causes of pseudopneumoperitoneum such as pneumomediastinum 9."
Expected headings
"Associations"
"There is a statistically significant association with high-velocity trauma (with an incidence of 12.5% of all high-velocity trauma) 9."