Brief HPI:

A middle-aged female with no known medical history is brought to the emergency department with altered mental status. Her family notes worsening confusion over the past 2-3 days associated with vomiting and yellow discoloration of skin and eyes.

Initial vital signs were normal, though with borderline hypotension (99/64mmHg). Examination demonstrated an alert, but lethargic patient with jaundice and scleral icterus, no skin lesions were appreciated. Laboratory studies were obtained:

Imaging:

CT Head: No acute intracranial process.

ED Course:

The patient developed worsening respiratory failure with hypoxia and tachypnea requiring endotracheal intubation. Thrombotic thrombocytopenic purpura was suspected and while awaiting emergent plasma exchange transfusion, the patient arrested and resuscitation efforts were unsuccessful.

The patient’s ADAMTS13 activity level was <3%. Autopsy demonstrated consolidation of the right middle lobe with possible lymphoproliferative mass, and lung petechial hemorrhages from microvascular thrombi.

Differential Diagnosis of Thrombocytopenia ^1-7

Algorithm for the Evaluation of Thrombocytopenia ⁸

Workup ^10,11

• hCG
• Repeat CBC
  • Detect spurious measure
  • Neutrophil-predominant leukocytosis: bacterial infection
  • Immature leukocytes (blasts): leukemia, myelodysplasia
• Peripheral smear
  • Schistocytes: microangiopathic process (DIC, TTP, HUS)
  • Atypical lymphocytes: viral infection
  • Intracellular parasites: malaria
  • Hypersegmented neutrophils: nutritional deficiency
• Infectious features: HIV, HCV, EBV, H.pylori, blood cultures
• Autoimmune features: ANA, APL-Ab
• Suspected occult liver disease: LFT, PT/PTT/INR
• Suspected thrombotic microangiopathy: PT/PTT/INR, haptoglobin, LDH, fibrinogen, FDP, d-dimer

Specific Conditions ^2-6,9,12-20

Disease	Cause	Presentation	Laboratory Findings	Treatment
DIC	Sepsis Trauma Burn Malignancy	Bleeding Multi-organ failure Shock	INR Fibrinogen FDP D-dimer	Directed at underlying cause Transfusion thresholds for hemorrhage: FFP for INR >1.5 Platelets if <50k Cryoprecipitate of fibrinogen <100mg/dL
TTP	Insufficient ADAMTS-13 activity	Non-specific constitutional symptoms (ex. weakness) Neuro: headache, AMS, focal neuro deficit GI: abdominal pain, nausea/vomiting	LDH Reticulocyte Unconjugated bilirubin Haptoglobin	Plasma exchange
HUS	Shiga-toxin-producing bacteria, E. coli O157:H7	Bloody diarrhea, anuria, oliguria, and hypertension		Aggressive supportive care
HELLP	Spectrum of eclampsia	Hypertension Visual symptoms Headache RUQ abdominal pain	AST/ALT Uric acid Unconjugated bilirubin LDH Reticulocyte Haptoglobin	Delivery, MgSO4
ITP	Primary ITP Secondary ITP – Drug – Autoimmune – Infection – Malignancy	Usually asymptomatic, may have petechiae or easy bruising	Isolated thrombocytopenia	Steroids
HIT	Exposure to heparin or LMWH	Thrombocytopenia or a 50 percent reduction in platelet count between 5-10d exposure New thrombosis or skin necrosis 4 T’s score	Platelet factor 4 antibodies	Withdraw heparin

References

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