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Haematology & Oncology

Disseminated Intravascular Coagulation (DIC)

Disseminated intravascular coagulation is a dynamic, acquired syndrome of systemic coagulation activation driven by another serious illness, causing microvascular thrombosis while consuming platelets and clotting factors; treat the trigger first and support bleeding selectively.

In a nutshell

DIC is a dynamic consumptive coagulopathy caused by severe underlying illness. It can cause bleeding, thrombosis or both; diagnose it from the clinical context and serial results, treat the cause urgently, and give blood components for bleeding or a high-risk procedure rather than abnormal numbers alone.

Classic presentation

A septic or otherwise severely unwell patient develops oozing from lines or wounds, falling platelets, prolonged PT or APTT, changing fibrinogen and raised D-dimer, with or without organ dysfunction or acral ischaemia.

Key points

  • DIC is always secondary: look for sepsis, trauma, acute promyelocytic leukaemia, disseminated malignancy or an obstetric emergency.
  • No single test diagnoses DIC; combine the clinical context with serial FBC, PT, APTT, fibrinogen and fibrin degradation markers. An ISTH score of 5 or more supports overt DIC.
  • Treat the trigger and any source of infection urgently; source control can be as important as antibiotics.
  • In bleeding or before a high-risk procedure, use the BSH and local transfusion protocol to decide when platelets, plasma or fibrinogen replacement are indicated.
  • Do not transfuse a stable, non-bleeding patient just to normalise the coagulation screen; use specialist and local transfusion advice.
  • Non-bleeding critically ill patients generally need VTE prophylaxis when safe; therapeutic heparin is a specialist decision for thrombosis-predominant DIC or another confirmed indication.

First-line investigation

Serial FBC, blood film, PT, APTT, fibrinogen and D-dimer or local fibrin degradation markers, alongside cultures, lactate, organ-function tests and targeted investigation of the underlying trigger.

Management

Escalate and identify the phenotype

  • Use ABCDE, senior review and early haematology or critical-care involvement. Look immediately for major or critical-site bleeding, shock, organ dysfunction, acral ischaemia and the underlying trigger.1,4

Confirm a dynamic consumptive pattern

  • Send FBC, blood film, PT, APTT, fibrinogen, D-dimer or local fibrin degradation markers, group and crossmatch, renal and liver tests, lactate and trigger-directed tests; repeat according to severity and local protocol.1,4
  • Use the ISTH score only with an appropriate underlying disorder and clinical assessment; a score of 5 or more supports overt DIC, while an evolving lower score needs serial reassessment.1

Treat the cause and support organs

  • Treat sepsis through the current NICE risk-based pathway, including timely antibiotics and early source-control assessment; use urgent disease-specific pathways for trauma, obstetric emergencies, acute promyelocytic leukaemia and malignancy.1,4,5,6
  • Resuscitate and support organ function through the local sepsis or major-haemorrhage protocol, activating coordinated transfusion support for life-threatening bleeding.4,7

Replace components only for clinical need

  • For clinically significant bleeding or a high-risk procedure, consider platelets when the count is below 50 × 10^9/L, plasma for clinically relevant prolonged PT or APTT, and fibrinogen replacement or cryoprecipitate when severe fibrinogen depletion below 1 g/L persists; follow specialist and local transfusion guidance.1,3,2
  • For thrombosis-predominant DIC, confirmed VTE or a non-bleeding critically ill patient, involve haematology to balance therapeutic anticoagulation or VTE prophylaxis against bleeding risk; therapeutic heparin is not routine DIC treatment.1

Trend recovery and safety-net deterioration

  • Repeat examination and coagulation results until the trigger and consumptive pattern are improving; revisit source control or the diagnosis if bleeding, organ dysfunction, thrombosis or laboratory deterioration persists.1,4

Exam traps

  • DIC is not the same as isolated thrombocytopenia: falling platelets with changing clotting and fibrin markers should trigger a search for a systemic cause.
  • Schistocytes can occur in DIC but also in TTP and other microangiopathies; a normal coagulation screen in a compatible presentation should prompt urgent consideration of TTP rather than reassurance.
  • A normal or near-normal fibrinogen does not exclude early or compensated DIC, especially when inflammation is increasing fibrinogen production.
  • Do not give platelets or FFP solely to correct laboratory values in a stable, non-bleeding patient.
  • Acute promyelocytic leukaemia with DIC is a haematological emergency requiring an urgent disease-specific pathway; do not wait for a complete routine work-up before seeking specialist advice.
  • The older BSH DIC page contains historical treatment advice that is no longer current; do not reproduce obsolete activated protein C recommendations.

Illustrations

Schistocytes on the blood filmA blood film showing fragmented red cells (schistocytes) and reduced platelets, with a note that schistocytes indicate microangiopathic injury but are not specific for DIC.Prof. Osaro Erhabor, Wikimedia Commons · CC0

Key sources

  1. British Society for Haematology, Guidelines for the diagnosis and management of disseminated intravascular coagulation (Published 13 February 2009; last review 9 January 2012; used for diagnosis, serial assessment, cause-directed treatment and selective component support)Published 13 Feb 2009 | Updated 9 Jan 2012
  2. British Society for Haematology, Spectrum of fresh frozen plasma and cryoprecipitate products (Published 12 March 2018; last review 17 October 2023, including the current addendum)Published 12 Mar 2018 | Updated 17 Oct 2023
  3. British Society for Haematology, Guidelines for the use of platelet transfusions (Adult platelet transfusion guidance; published 23 December 2016 and last reviewed 14 January 2022)Published 23 Dec 2016 | Updated 14 Jan 2022
  4. NICE NG253, Suspected sepsis in people aged 16 or over: recognition, assessment and early management (Current NICE sepsis recommendations, including investigation, risk-based antibiotics and reassessment)Published 19 Nov 2025 | Updated 5 Dec 2025
  5. NICE NG253, source control and specialist management recommendations (Current NICE recommendations on early source-control assessment and intervention in suspected sepsis)Published 19 Nov 2025 | Updated 5 Dec 2025
  6. NICE NG253, antibiotics and reassessment in suspected sepsis (Current NICE risk-stratified timing and review recommendations; regimen selection remains source- and local-guideline-specific)Published 19 Nov 2025 | Updated 5 Dec 2025
  7. British Society for Haematology, Haematological management of major haemorrhage (Published 10 June 2022; addendum last reviewed 22 July 2025)Published 10 Jun 2022 | Updated 22 Jul 2025

This page is exam revision material, not medical advice, and must not be used for patient care. Always check drug doses against the BNF and current guidance. Full disclaimer.