The response of human cadavers and live anesthetized and postmortem primates and canines to blunt lateral thoraco-abdominal impact was investigated using a 10 kgm. free-flying mass. Injuries were evaluated by gross autopsy, and for live subjects, also by sequential peritoneal lavage and biochemical assays. Mechanical measurements included force time history, intra-aortic pressure, and high-speed cineradiography. The X-ray cineradiograph was shown to be invaluable as an in vivo, noninvasive technique for quantifying the motion of internal structures during impact. The heart's response during the time of contact was affected by interactions with other material bodies (diaphragm, thoraco-abdominal wall, and lung tissue). During impacts of 12 msec. or less, the hepatic system acted as a deformable structure. Injury severity (Abbreviated Injury Scale) was lower for the unpressurized postmortem subjects than for the live subjects. Elevated levels of the enzymes glutamic-oxalacetic transaminase and glutamic-pyruvic transaminase occurred in both the circulatory system and the peritoneal cavity within one half hour following blunt abdominal impact trauma. Evaluation of abdominal injury severity by gross autopsy was found to lack interpretation of such critical factors as hemorrhaging.
Abstract