If TTP is suspected, laboratory testing should include lactate dehydrogenase (LDH), haptoglobin, and a smear for schistocytes to check for microangiopathic hemolytic anemia (MAHA). A test to assess for ADAMTS-13 level may also be considered. The next best step in treatment is to admit the patient to the intensive care unit (ICU) with an urgent hematology consult to begin plasmapheresis.
TTP is a rare but serious condition of unknown etiology that is characterized by thrombocytopenia and MAHA. Clinical findings may include skin purpura as well as gastrointestinal and/or neurologic issues. The classic pentad can be remembered by the mnemonic PATCH: Pyrexia, Azotemia, Thrombocytopenia, CNS findings, and Hemolysis; however, it is rare to find all 5 elements in a patient presenting with TTP. Stimulant drugs or certain medications may cause TTP, as do infection, pregnancy, and cancer.
Treatment for TTP should begin with admission to the ICU with an urgent hematology consult for immediate initiation of plasmapheresis. Complications that arise can be either hemorrhagic or thrombotic and may include myocardial infarction, cerebrovascular accident, organ ischemia, and central nervous system or gastrointestinal bleeding. Early treatment has been shown to decrease both morbidity and mortality from TTP.
Initially, LDH and bilirubin levels were elevated but no schistocytes were found. Treatment did not begin until the day after admission the ICU; by this time, the patient’s platelet count had dropped from 85 × 103/μL to 9 × 103/μL. Repeat blood count now revealed schistocytes. The patient received multiple rounds of plasma exchange and recovered fully.
Brady Pregerson, MD, is an emergency physician at Cedars-Sinai Medical Center in Los Angeles and at Tri-City Medical Center in Oceanside, California.
Pregerson DB. Emergency Medicine 1-Minute Consult Pocketbook. EMresource.org. 2017;5.