Intravascular or fragmentation hemolysis results from what type of injury?

Intravascular or fragmentation hemolysis primarily results from trauma to red blood cells (RBCs) while in circulation. This type of hemolysis occurs when RBCs encounter physical damage or shear stress that leads to their fragmentation. Such injuries can be caused by various factors, including mechanical forces from turbulence in blood flow, presence of prosthetic heart valves, or severe microangiopathic conditions, where small blood vessels are obstructed or damaged.

This physical trauma disrupts the integrity of the red blood cell membranes, ultimately causing the cells to rupture and release their hemoglobin into the bloodstream. This process is distinct from other forms of hemolysis, which might involve antibody-mediated destruction or other systemic factors. The characteristics of intravascular hemolysis include increased levels of free hemoglobin in the plasma and signs of hemolysis such as elevated lactate dehydrogenase (LDH) and decreased haptoglobin.

In summary, the correct answer emphasizes the role of mechanical trauma in causing intravascular hemolysis, distinguishing it from other mechanisms of hemolysis linked to different pathophysiological processes.