Trauma can be defined as an injury to living tissue caused by an extrinsic agent. Trauma was estimated to have caused 10% of all deaths occurring in 1990 world-wide. The leading causes of trauma death are blunt trauma, motor vehicle collisions and falls. Mortality can be grouped into immediate, early, and late deaths. Immediate deaths are caused by a fatal injury of the great vessels, heart, or neurologic system. Early trauma deaths result from failed oxygenation of the vital organs, massive central nervous system injury, or both. The mechanisms of failed tissue oxygenation include inadequate ventilation, impaired oxygenation, circulatory collapse, and insufficient end-organ perfusion. Massive central nervous system trauma leads to inadequate ventilation and/or disruption of brainstem regulatory centers. Late trauma mortality peaks from days to weeks after the injury and is primarily due to sepsis and multiple organ failure.