Traumatic hemolytic anemiaIntroduction: When
there are multiple injuries to a person from a motor vehicle accident or from
an assault, red blood cells can get damaged from the transmitted forces and blood
vessel compression. On
a microscopic level the hematologist can see red blood cell fragments with odd
shapes in a blood smear. The hematologist will term these with names such as helmet
shapes, triangles etc. Medically they are also known as “schistocytes”(see
arrows) . The bone marrow, spleen and liver are lined with special cells, called
reticulocytes that will remove these red blood cell fragments. The spleen and
the liver are particularly well equipped to do this cleansing of the blood. If
the trauma stops and was limited, a steady state is reintroduced by the release
of reticulocytes from the bone marrow that is the last precursor of new red blood
cells. Traumatic hemolytic anemia can occur also in other clinical situations
such as with calcific aortic stenosis, with malfunctioning artificial aortic valves,
with repetitive foot striking from marching (called “march hemoglobinuria”).
Other such conditions are extremely high blood pressure (malignant hypertension),
thrombotic thrombocytopenic purpura, disseminated intravascular coagulation (DIC),
disseminated cancer, hemolytic-uremic syndrome, lupus erythematosus and polyarteritis
nodosa that can also lead to traumatic hemolytic anemia because of damaged small
blood vessels. Diagnostic tests: The blood tests
show the hallmarks of a hemolytic anemia with a low mean corpuscular volume (MCV),
but a high distributions width due to the fragments of red blood cells in the
blood. Iron deficiency occurs, when there has been a chronic hemosiderinuria (loss
of iron through urine). Treatment: Treatment is directed at the
underlying cause. Iron loss can be remedied with iron replacement therapy for
a period of time. |
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