Polytrauma and multiple trauma are medical terms describing the condition of a person who has been subjected to multiple traumatic injuries, such as a serious head injury in addition to a serious burn. The term is defined via an Injury Severity Score (ISS) equal to or greater than 16. It has become a commonly applied term by US military physicians in describing the seriously injured soldiers returning from Operation Iraqi Freedom in Iraq and Operation Enduring Freedom in Afghanistan. The term is generic, however, and has been in use for a long time for any case involving multiple trauma. In civilian life, polytraumas often are associated with motor vehicle crashes. This is because car crashes often occur at high velocities, causing multiple injuries. On admission to hospital any trauma patient should immediately undergo x-ray diagnosis of their cervical spine, chest, and pelvis, commonly known as a 'trauma series', to ascertain possible life-threatening injuries. Examples would be a fractured cervical vertebra, a severely fractured pelvis, or a haemothorax. Once this initial survey is complete, x-rays may be taken of the limbs to assess the possibility of other fractures. It also is quite common in severe trauma for patients to be sent directly to CT or a surgery theatre, if they require emergency treatment. Extracorporeal membrane oxygenation (ECMO) may be effective in treating some polytrauma patients with pulmonary or cardiopulmonary failure. Military medicine Polytrauma often results from blast injuries sustained from improvised explosive devices, or by a hit with a rocket-propelled grenade, with "Improvised explosive devices, blasts, landmines, and fragments account[ing] for 65 percent of combat injuries ...". The combination of high-pressure waves, explosive fragments, and falling debris may produce multiple injuries including brain injury, loss of limbs, burns, fractures, blindness, and hearing loss, with 60 percent of those injured in this way, having some degree of traumatic brain injury.