DIC vs TTP
How to tell DIC and TTP apart when a board question makes them look alike.
Step 2 CK pairs are in open beta while clinical review finishes. Spot an issue? Tell us.
Normal PT and aPTT with MAHA points to TTP rather than DIC.
Side by side
Schistocytes with prolonged PT and aPTT plus low fibrinogen suggest disseminated intravascular coagulation.
Schistocytes with thrombocytopenia and normal coagulation times suggest thrombotic thrombocytopenic purpura.
Systemic tissue factor activation causes diffuse thrombin generation with consumption of platelets and clotting factors.
Severe ADAMTS13 deficiency causes large von Willebrand multimers and platelet-rich microthrombi.
DIC profile includes platelets often below 100000/uL, PT prolonged, aPTT prolonged, fibrinogen below 150 mg/dL, and markedly elevated D-dimer.
TTP profile includes platelets often below 30000/uL, normal PT and aPTT, hemolysis with LDH elevation, and ADAMTS13 activity below 10 percent when resulted.
The trap
Waiting for ADAMTS13 results before treatment can be fatal in TTP. If MAHA and thrombocytopenia occur with preserved coagulation studies and neurologic changes, start plasma exchange immediately.
The repair move
Next best step: start urgent daily plasma exchange and high-dose methylprednisolone for presumed TTP, avoid platelet transfusion unless life-threatening bleeding, and send ADAMTS13 testing without delaying therapy. Treat DIC instead by controlling the trigger source and replacing blood products when bleeding or procedures require correction.
Try a free question
CoreA 55-year-old man with septic shock has oozing from IV sites, schistocytes, platelets 54000/uL, PT 22 seconds, aPTT 54 seconds, and fibrinogen 90 mg/dL. What is the next best step in management?
Show answer and explanation
Answer: A. Treat underlying sepsis and give blood product support as indicated. This coagulation profile indicates DIC, so management targets the trigger and corrects bleeding risk with guided transfusion.
Why the other choices are tempting
- B. Wrong. Plasma exchange is for TTP with normal coagulation studies.
- C. Wrong. Isolated platelet transfusion is incomplete and unsafe in active DIC.
- D. Wrong. Heparin is selective, not universal, and not first in bleeding septic DIC.
- E. Wrong. Untreated DIC can rapidly progress to multiorgan failure and hemorrhage.
Flashcards
Tap a card to flip it.
Which coagulation profile separates TTP from DIC in a thrombocytopenic hemolytic patient?
Normal PT and aPTT favor TTP, while prolonged PT and aPTT favor DIC.
What fibrinogen pattern is typical in DIC?
Low fibrinogen with elevated D-dimer from consumptive coagulopathy.
Quick answers
What is the fastest way to tell DIC from TTP?
Normal PT and aPTT with MAHA points to TTP rather than DIC.
What is the key clue for DIC?
Schistocytes with prolonged PT and aPTT plus low fibrinogen suggest disseminated intravascular coagulation.
What is the key clue for TTP?
Schistocytes with thrombocytopenia and normal coagulation times suggest thrombotic thrombocytopenic purpura.
What is the common trap with DIC vs TTP?
Waiting for ADAMTS13 results before treatment can be fatal in TTP. If MAHA and thrombocytopenia occur with preserved coagulation studies and neurologic changes, start plasma exchange immediately.