Trauma Care After Resuscitation (TCAR) Practice Exam

Secondary brain injury refers to damage that evolves after the initial insult and worsens outcome. The listed processes—tissue ischemia/hypoxia, inflammation, and edema—are all examples of secondary injury. Ischemia or hypoxia reduces oxygen delivery to brain tissue after the injury, often from systemic hypotension, impaired blood flow, or swelling that compresses vessels. Inflammation is a post-injury response involving microglial activation and cytokine release that can expand the injury area and damage neurons and glia. Edema arises from disruption of the blood-brain barrier and cellular injury, increasing intracranial pressure and further reducing perfusion. These processes often interact, fueling a cycle that amplifies injury beyond the initial event. Thus, all of the listed phenomena are secondary brain injuries.