Thrombotic microangiopathy

This code represents thrombotic microangiopathy (TMA), a group of disorders characterized by microvascular thrombosis, thrombocytopenia, and microangiopathic hemolytic anemia. It involves damage to small blood vessels, leading to the formation of tiny blood clots that consume platelets and fragment red blood cells.

Use this code when documentation explicitly states a diagnosis of thrombotic microangiopathy, such as in cases of atypical hemolytic uremic syndrome (aHUS), thrombotic thrombocytopenic purpura (TTP), or drug-induced TMA. Supporting documentation should detail evidence of microangiopathic hemolytic anemia (e.g., schistocytes on blood smear), thrombocytopenia, and organ dysfunction related to microvascular thrombosis.

• Differentiate from other causes of hemolytic anemia or thrombocytopenia; TMA is a specific diagnosis.
• Code any underlying conditions or associated disorders, such as autoimmune diseases or infections, as additional diagnoses.
• Ensure documentation clearly distinguishes between primary TMA and secondary TMA, if known, as this may impact treatment and further coding.