USMLE Prep - Medical Reference Library

Disseminated Intravascular Coagulation — Diagnosis & Treatment

System: Hematology Oncology • Reviewed: Aug 31, 2025 • Step 1Step 2Step 3

Synopsis:

DIC is a consumptive coagulopathy from systemic activation of coagulation (sepsis, malignancy, trauma, obstetric). Diagnose with clinical context and labs (↑PT/INR, ↑aPTT, ↓fibrinogen, ↑D‑dimer, thrombocytopenia). Treat cause; provide targeted blood products; consider heparin in chronic DIC.

Key Points

  • Stabilize ABCs; begin targeted evaluation without delaying life-saving therapy.
  • Use system-specific risk tools to guide testing and disposition.
  • Order high-yield tests first; escalate imaging when indicated.
  • Start evidence-based initial therapy and reassess frequently.

Algorithm

  1. Primary survey and vitals; IV access and monitors.
  2. Focused history/physical; identify red flags and likely etiologies.
  3. Order system-appropriate labs and imaging (see Investigations).
  4. Initiate guideline-based empiric therapy (see Pharmacology).
  5. Reassess response; arrange consultation and definitive management.

Clinical Synopsis & Reasoning

For Disseminated Intravascular Coagulation Diagnosis Treatment, frame the differential by acuity and pathophysiology, then align diagnostics to the leading hypotheses. Prioritize stabilization while obtaining high‑yield studies such as CBC with diff (Cytopenias/leukocytosis), Coags (Bleeding/clotting), Smear (Morphology). Incorporate bedside imaging and targeted labs to define severity and identify complications; synthesize results with clinical trajectory to refine the working diagnosis and disposition needs.


Treatment Strategy & Disposition

Initiate disease‑directed therapy alongside supportive care, titrating to objective response. Pharmacologic options commonly include Anti-pseudomonal β-lactam. Use validated frameworks (e.g., ISTH DIC Score (Simplified)) to guide escalation and site of care. Address precipitating factors, de‑escalate empiric therapies with data, and arrange follow‑up for monitoring and risk‑factor modification; admit patients with instability, high risk of deterioration, or needs for close monitoring.


Management Notes

Avoid prophylactic transfusion without bleeding. Use viscoelastic testing (TEG/ROTEM) only as adjunct. Distinguish from TTP/HUS (schistocytes, severe ADAMTS13 deficiency).


Epidemiology / Risk Factors

  • Cytotoxic chemotherapy, neutropenia; lines

Investigations

TestRole / RationaleTypical FindingsNotes
CBC with diffCytopenias/leukocytosisAbnormal counts
CoagsBleeding/clottingAbnormalities
SmearMorphologyAbnormal cells

ISTH DIC Score (Simplified)

ParameterPoints
Platelets>100k=0, 50–100k=1, <50k=2
D‑dimer/FDPNo increase=0, moderate=2, strong=3
PT prolongation<3s=0, 3–6s=1, >6s=2
Fibrinogen≥100 mg/dL=0, <100=1
Score ≥5Overt DIC (supportive of diagnosis)

Pharmacology

MedicationMechanismOnsetRole in TherapyLimitations
Treat underlying causeN/AImmediateCornerstone therapy—; ED use
Cryoprecipitate/FFP/PlateletsReplace factors/plateletsHoursBleeding with lab derangementsTransfusion reactions; ED use
Heparin (selected)Antithrombin activationHoursPredominant thrombosisBleeding; ED use

Prognosis / Complications

  • Tied to depth/duration of neutropenia and comorbidities

Patient Education / Counseling

  • Explain red flags and when to seek emergent care.
  • Reinforce medication adherence and follow-up plan.

References

  1. ISTH DIC Guidance — Link