Introduction
Traumatic hemolytic anemia can develop when there are multiple injuries to a person from a motor vehicle accident or from an assault; this is when red blood cells can get damaged from the transmitted forces and blood vessel compression.
Hemolytic anemias from changes outside of the RBC
1. Autoimmune hemolytic anemias (link accessible from “Related Topics” below)
2. Traumatic hemolytic anemia (this page)
3. Splenomegaly and Hypersplenism (link accessible from “Related Topics” below)
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.
References
1. Merck Manual (Home edition): Anemia
2. Noble: Textbook of Primary Care Medicine, 3rd ed., Mosby Inc. 2001
3. Goldman: Cecil Medicine, 23rd ed., Saunders 2007: Chapter 162 – APPROACH TO THE ANEMIAS
