Case Presentation by Dr. Sam Sadler
41 yo female presents to the ARC with chief complaint of “rash and not feeling well.” She says her symptoms have been present for 7 days consisting of malaise initially and today she developed a rash on her bilateral upper and lower extremities. She had a few episodes of chills associated with tactile fevers. No sick contacts. No runny nose, cough, abdominal pain, vomiting or diarrhea.
Since this is the ARC you quickly go to your physical exam expecting of course to find a whole lot of nothing since obviously this patient cant possibly be sick as they have been triaged to the “low acuity” area….
constitutional: tactile fevers
PMH: No HTN or illnesses
FH: HTN, DM, Rheumatoid Arthritis
SH: Smokes, drinks etoh, smokes marijuana denies other illicits, multiple partners
PE: BP: 145/88, HR: 72, RR: 20, Temp: 37.9
Constitutional: Anxious appearing obese female.
Skin: Non blanching rash as seen below:
Resp: CTA b/l
Card: S1S2 no abnormal heart sounds
Gastro: Soft, Nondistended
Neurologic: Smiles symmetrically, protrude the tongue is midline, 5 out of 5 strength in the upper and lower extremities, no loss of feeling in a dermatomal distributions of the upper or lower extremities. Normal cerebellar testing and normal gait.
Just as you are about to walk out of the room and re-triage this patient she drops her cell phone and shrieks “my arm is numb!!” You examine her right upper extremity and notice that her strength is 0/5 on grip testing, bicep/tricep testing and shoulder girdle the rest of her neuro exam is unchanged.
You race to your attending and share the history. When the attending evaluates the patient the neurologic exam is completely normal. Fully aware that petechia are bad and something must be done your transfer your patient to module 4 where Tabby and the intern are working… When you call module 4 Tabby says “We are in the weeds over here can you put some orders in for that patient?” You agree thinking to yourself I have no idea what orders to put in…. but send a CBC, lytes and coagulation studies.
1) If you could only order one study to make a definitive diagnosis which would it be?
a. CT Scan
b. CBC alone
c. CBC with peripheral smear
d. Urine electrolytes
e. Comprehensive metabolic panel
The nurse informs you of a panic value plt count of 8,000.
2) Which symptoms are the most common in the presentation of this disease?
a. petechia and fever
b. thrombocytopenia, hemolytic anemia, and acute renal failure
c. thrombocytopenia, fever, hemolytic anemia, and acute renal failure
d. thrombocytopenia, microangiopathic hemolytic anemia, and neurologic deficit
The patients other labs return showing normal basic metabolic profile, hemoglobin of 6.2 mg/dL and . She now has abdominal pain and her arm isn’t working again.
3) Which of the following therapies is an absolute contraindication to the definitive therapy for this disease?
c. 2L D5W 0.9 NaCL bolus
c, d, d
The diagnosis for this patient is TTP. distinguishing this from say ITP important as the prognosis is significantly different. Thrombotic thrombocytopenia purpura is rare however if left untreated mortalitity is 100% but with proper treatment it is reduced to 10-20% It is a true hematologic emergency, one of very few. So it must be on the radar and we must know what to do for these patients. ITP an autoimmune disease that targets platelets on the otherhand is relatively benign. They are generally going to have a drop in platelets to less than 50,000/mm3 with associated petechia or purpura. It is associated with other autoimmune diseases. These patients should get basic labs including coags but they will essentially have a isolated thrombocytopenia. ITP treatment in the emergency department is simple with steroids and admission only necessary when patients are actively bleeding or cannot arrange timely outpatient follow up.
The diagnosis of TTP is mostly based on history and physical but you will likely need labs to get a hematologist out of bed…
The textbook will say that there is a pentad of findings: some neurologic finding, thrombocytopenia, fever, hemolytic anemia, and acute renal failure however these are only all present 1/3 of the time. However ¾ of the time a triad is present: thrombocytopenia, microangiopathic hemolyctic anemia (MAHA) and neurologic deficit. Thrombocytopenia is commonly defined as anything below 50/ml. MAHA is the presents of schistocytes on smear. And the neurologic symptoms are usually focal and transient almost like TIA they may not be active at the time of presentation so it is important to ask about it in the history. On physical exam you will find the petechia, jaundice and most patients have splenomegaly as the spleen tries to sequester all of the schistocytes. Risk factors are obesity, african american, female, rheumatologic diseases, HIV and taking plavix.
For labs you are going to need a CBC for platelet count a smear, Lytes for renal failure although not always present at time of presentation, unconjugated bilirubin, UA for hematuria. The CBC with smear is most important because it will demonstrate the schistocytes and low platelets confirming microangiopathic hemolytic anemia and thrombocytopenica. Bonus points from your hematologist if you send off an ADAMTS13 study to included level, activity level and function. This is a protease which is key in the pathophysiology of TTP. It’s job is to cleave vWF therefor the lack and/or decreased function of it forms long chains in the middle of capillaries which the platelets adhere to resulting in platelet aggregation which leads to consumption and clotting.
Definitive treatment is plasma exchange transfusion which will remove the bad proteases (ADAMTS13) and replace them with functional proteases. However this needs to be initiated usually by the hematologist or really by the blood bank so in a bind you could call them directly. Regardless early consult with the hematologist is imperative. In the meantime steroids and fluids are really the mainstay of treatment in the emergency department. FFP can also be given as this will provide ADAMTS13 but again the definitive treatment is exchange transfusion. Patients who are anemic are going to need PRBC’s as well. Any blood product containing platelets is absolutely contraindicated as more platelets will only fuel the fire. With appropriate treatment mortality goes from 100% to 10-20%.
Kessler et al. Thrombotic thrombocytopenic purpura: a hematological emergency. J Emerg Med. 2012 Sep;43(3):538-44.
Rosen’s Emergency Medicine. 7th ed. 2010. Marx.