You are called to a patient room to evaluate for new onset fever and altered mental status. Upon chart review: 56 year old female in the hospital for nausea and vomiting with acute kidney injury. Patient has known history of HTN on hydrochlorothiazide. Nursing staff says the patient was AOx4 earlier in the day.
Meds: IV Saline for hydration, HCTZ.
Vitals: T: 101.8F, RR 18, HR: 90, BP 98/50, Sat: 98%
PE: Pt slightly diaphoretic, AOx0, RRR, Clear lungs, no abdominal tenderness. Moving all 4 extremities, EMOI, PERRL. No skin lesions noted.
Repeat labs were ordered significant for:
WBC 11.7
RBC 9.0
Platelets: 21 (previous day 72)
Creatinine: 2.50 (previous day 1.79)
Additional labs ordered:
LDH - Elevated
Fibrinogen - Decreased
Blood smear: Schistocytes and decreased platelets
Thrombotic thrombocytopenic purpura (TTP) is a disorder that affects 2 patients per million each year, affecting women and African American patients more often. TTP is thought to be caused by a genetic or idiopathic deficiency in ADAMTS13 or a decrease in ADAMTS13 secondary to autoimmune antibodies. ADAMTS13 is an enzyme that cleaves von Willebrand Multimers that are thrombotic. Idiopathic deficiency of ADAMTS13 can be caused by infection, autoimmune diseases, pregnancy, medications, or cancer.
Clinical Presentation:
Classically TTP presents with the Pentad of:
Fever
Anemia (MAHA)
Thrombocytopenia
Renal abnormalities
Neurologic changes
The acronym FAT RN has been used to remember the pentad. The pentad presents in <5% of all patients; it is usually a marker of a patient in the late stages of TTP.
Laboratory Presentation:
Thrombocytopenia
Elevated LDH - Signaling elevated Hemolysis
Elevated Bilirubin (Indirect)
Schistocytes on blood smear
Fibrinogen - Normal
Treatment:
In the emergency department starting Methylprednisolone 1.5mg/kg/day is appropriate.
Treatment is based around replacement of ADAMTS13 or removing the offending antibody.
Plasma Exchange
In conjunction with hematology
If hematology is unavailable, FFP may be started pending transfer.
Platelet Transfusion
Controversial, consultation with a hematologist is recommended.
References:
Miguel Christopher San, Kaide Colin. Thrombocytopenia. In: Mattu A and Swadron S, ed. CorePendium. Burbank, CA: CorePendium, LLC. https://www.emrap.org/corependium/chapter/recsZKZRF5K3gPAJV/Thrombocytopenia#h.aw7klus4krob. Updated December 14, 2019. Accessed December 14, 2019.