Circumstances:
(1) accidental discharge
(2) prank
(3) while using compressed air to clean dust off clothing
(4) criminal intent
Facts:
(1) Clothing does not protect.
(2) The closer the nozzle to the anus, the greater the risk, but rupture can occur even with the nozzle some distance away from the anus.
(3) A pressure of 4.07 psi (0.29 kg per square cm) is sufficient to cause a transmural rupture. The pressure in a compressed air system is often more than 10 times this level.
(4) One second of high pressure is sufficient to cause injury.
(5) The rate at which air is introduced may be more important than pressure in the air hose.
Colonic rupture:
(1) There may be a single or multiple sites of rupture.
(2) The onset of symptoms may immediate or it may be delayed several days. Some patients may be asymptomatic at first.
(3) While most injuries occur at the rectosigmoid junction and sigmoid colon, perforations can occur in the ascending colon, at the splenic flexure, in the transverse colon, or at the hepatic flexure.
(4) Air can dissect along the length of the colon, with the site of actual rupture distant from the point of mucosal disruption.
Complications:
(1) rhabdomyolysis
(2) pneumoperitoneum, pneumothorax, subcutaneous emphysema and/or pneumomediastinum
(3) peritonitis
(4) shock
