Episode 016: Heme/Onc Emergencies, Pt. 5: DIC and Intro to TMAs
Emergencies happen in hematology and oncology. This is a fact. But how do we manage these emergencies? Look no further.
In this episode, we talk all about our second hematologic emergency: disseminated intravascular coagulation (DIC) with an added bonus of an intro to thrombotic microangiopathic anemias (TMAs).
Disseminated intravascular coagulation (DIC):
Be sure to check out episode 009 on thrombocytopenia for a general approach and differential!
Workup:
CBC
CMP
PT, PTT, INR
Fibrinogen
Peripheral smear - concern for schistocytes. Example of these cells from ASH image bank here
Basic mechanism of DIC is consumption of clotting factors leading to coagulopathy
Need to be weary of thrombotic microangiopathy:
Small blood clots forming in the small vessels leading to endothelial damage, which cause shear stress on the RBCs, which then break down into a schistocyte (AKA triangulocyte or helmet cell)
Examples: DIC, thrombotic thrombocytopenic purpura (TTP), and hemolytic uremic syndrome (HUS)
Management (our opinion!):
Repeat coags q4-6 hours initially (but base interval based on patient)
NOTE: INR Is NOT a good assessment of “clotting status” in these situations
Repeat fibrinogen q4-6 hours initially (but base interval based on patient); keep fibrinogen >100 with cryoprecipitate in more stable patients; consider higher thresholds for more acutely ill patients (such as >150)
Repeat CBC q6-8 hours initially; can provide platelets if low, especially if they are bleeding
Workup and treatment for trigger of DIC (infection, trauma, medications, etc.)
How does cirrhosis affect data interpretation?
Use clinical context to determine if labs are acutely abnormal or if they have signs/symptoms to suggest underlying liver dysfunction
In the acute setting, always just replace what is missing!
How can you tell the difference between nutritional deficiencies vs. consumption (as in with DIC?)
Factor activity levels!
Consider checking: Factor 8 (made in endothelium), Factor 5 (Vit K independent), Factor 7 (vitamin K dependent)
If all down, then most likely DIC
If Vit K-dependent low but factor 5 normal, then nutritional deficiency
If Factor 5 and Factor 7 low but Factor 8 normal, then related to liver disease +/- nutritional
Reference:
https://ashpublications.org/blood/article/131/8/845/104418/How-I-treat-disseminated-intravascular-coagulation - Great How I Treat article from Blood
