A 22-year-old female is brought to the emergency room by her mother because of fever (38.7ºC) and changed mental status. Mother states that her daughter has been behaving very strangely for the last 8 hours. It appears that she does not know what time it is or where she is. From time to time she appears very frightened and mumbles without sense. She has been healthy before this episode. Her menstrual cycle has been regular in the past, but now she has had a menstrual cycle almost 2 weeks before her regular time. Her vital signs are as follows: Temp - 38.1ºC (after one 500 mg tablet of acetaminophen given by mother at home), BP - 138/87, pulse – 123 min, and respirations – 22 min. On physical examination patient is frightened, uncooperative, at moments combative. She does not answer even simple questions. She has no major neurologic deficit as judged from spontaneous movement of all extremities, normal muscle power, and obvious reactions to sounds, changes in light or touch. There is no appreciable facial asymmetry. There are no signs of injury. Laboratory findings are as follows: Na – 142, K – 4.3, Cl – 108, CO2 –25, Glucose – 88, BUN – 27, Cr – 1.4, WBC – 8.3, AST – 27, ALT – 34, LDH - 1124, Bilirubin – 3.4, Hb – 9.2, Hct – 28.1, Platelets – 43 000, PT – 11.2, INR – 1.1, PTT – 27. Toxicology screen is negative. Urinalysis reveals some proteinuria and is otherwise within normal limits. Peripheral blood smear is shown on the picture. What is the diagnosis?
The presence of thrombotic thrombocytopenic purpura –
hemolytic uremic syndrome (TTP – HUS) should be suspected
when a patient presents with the characteristic set of
clinical and laboratory findings without another
clinically apparent etiology.
These findings are:
- Microangiopathic hemolytic anemia (seen in
peripheral blood smear as a prominent red
cell fragmentation (schistiocytes), and
laboratory findings of increased LDH,
indirect bilirubin and reduction in serum
haptoglobin)
- Thrombocytopenia (often associated with
purpura, but usually without severe bleeding)
- Acute renal insufficiency that may be so
severe that it requires acute dialysis
(urinalysis is usually near normal or
only with mild proteinuria, and few cells
or casts
- Neurologic abnormalities (most commonly
confusion and headache, but seizures and
coma have been described)
- Fever
Differentiation from disseminated intravascular coagulation (DIC) may be difficult at times, but DIC is associated with different disorders than TTP – HUS (such are sepsis, shock, and preeclampsia and eclampsia). Also, DIC causes consumption coagulopathy characterized by low circulating levels of fibrinogen and factors V and VIII, prolongation of prothrombin, and partial thromboplastin time.
Sepsis should be in differential diagnosis especially if fever is spiking, very high, and associated with chills.
Acute drug induced psychosis is much less likely in this patient because of the presence of typical signs and symptoms of hemolytic anemia and renal insufficiency as suggested by the negative results of toxicology screen. In addition, it is unlikely that this patient suffers from sickle cell disease because of negative history and atypical presentation.
The patient in question has all attributes of the syndrome and should be treated emergently.
