Fatal arterial gas embolism: detection by chest radiography and imaging before autopsy.

Two recent cases are reported from north Queensland of deaths from massive arterial gas embolism occurring in tourists scuba diving on the Great Barrier Reef. The diagnosis was established in each case by an external examination of the body, followed by a plain erect chest radiograph soon after death and before autopsy; in one of the cases it was further confirmed before autopsy by computed tomography (CT) of the head, neck and thorax. The diagnosis was also supported by analysis of a diving profile, inspection and investigation of diving equipment, and autopsy. In the light of previously published advice and reports, the experience gained from these two cases now dictates that investigation of an unexplained death occurring after exposure to, and change from, hyperbaric or hypobaric conditions, should begin with plain erect chest radiography on the body before autopsy. Combining this with a pre-autopsy supine chest film before standing the body erect, and CT scanning of the head, neck and chest, is also recommended.